added the async code from Vert.x and Netty

NOTICE.txt

@@ -1,4 +1,30 @@
-The work in org.xbib.event.async is based upon the work in
+The work in org.xbib.event.async is based upon io.vertx.core in
+
+https://github.com/eclipse-vertx/vert.x
+
+branched as of 26 Apr 2023.
+
+/*
+ * Copyright (c) 2011-2019 Contributors to the Eclipse Foundation
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
+ * which is available at https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
+ */
+
+The work in org.xbib.event, org.xbib.event.thread, org.xbib.event.loop, org.xbib.event.util is based on netty
+
+https://github.com/netty/netty/
+
+branch 4.1 as of 26 Apr 2023.
+
+Licence: Apache 2.0
+
+
+The work in org.xbib.event.io is based upon the work in
 
 https://github.com/javasync/RxIo
 

gradle.properties

@@ -1,5 +1,5 @@
 group = org.xbib
 name = event
-version = 0.0.1
+version = 0.0.2
 
 org.gradle.warning.mode = ALL

gradle/ide/idea.gradle

@@ -5,9 +5,9 @@ idea {
         outputDir file('build/classes/java/main')
         testOutputDir file('build/classes/java/test')
     }
-}
+    project {
-
+        jdkName = '17'
-if (project.convention.findPlugin(JavaPluginConvention)) {
+        languageLevel = '17'
-    //sourceSets.main.output.classesDirs = file("build/classes/java/main")
+        vcs = 'Git'
-    //sourceSets.test.output.classesDirs = file("build/classes/java/test")
+    }
 }

src/main/java/module-info.java

@@ -1,12 +1,14 @@
 module org.xbib.event {
     exports org.xbib.event;
-    exports org.xbib.event.async;
     exports org.xbib.event.bus;
     exports org.xbib.event.clock;
     exports org.xbib.event.persistence;
     exports org.xbib.event.queue;
     exports org.xbib.event.syslog;
     exports org.xbib.event.yield;
+    exports org.xbib.event.io;
+    exports org.xbib.event.loop;
+    exports org.xbib.event.loop.selector;
     requires org.xbib.datastructures.api;
     requires org.xbib.datastructures.common;
     requires org.xbib.datastructures.json.tiny;

src/main/java/org/xbib/event/AbstractFuture.java

@@ -0,0 +1,43 @@
+package org.xbib.event;
+
+import java.util.concurrent.CancellationException;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+
+/**
+ * Abstract {@link Future} implementation which does not allow for cancellation.
+ *
+ * @param <V>
+ */
+public abstract class AbstractFuture<V> implements Future<V> {
+
+    @Override
+    public V get() throws InterruptedException, ExecutionException {
+        await();
+
+        Throwable cause = cause();
+        if (cause == null) {
+            return getNow();
+        }
+        if (cause instanceof CancellationException) {
+            throw (CancellationException) cause;
+        }
+        throw new ExecutionException(cause);
+    }
+
+    @Override
+    public V get(long timeout, TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException {
+        if (await(timeout, unit)) {
+            Throwable cause = cause();
+            if (cause == null) {
+                return getNow();
+            }
+            if (cause instanceof CancellationException) {
+                throw (CancellationException) cause;
+            }
+            throw new ExecutionException(cause);
+        }
+        throw new TimeoutException();
+    }
+}

src/main/java/org/xbib/event/CompleteFuture.java

@@ -0,0 +1,135 @@
+package org.xbib.event;
+
+import org.xbib.event.loop.EventExecutor;
+
+import java.util.Objects;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * A skeletal {@link Future} implementation which represents a {@link Future} which has been completed already.
+ */
+public abstract class CompleteFuture<V> extends AbstractFuture<V> {
+
+    private final EventExecutor executor;
+
+    /**
+     * Creates a new instance.
+     *
+     * @param executor the {@link EventExecutor} associated with this future
+     */
+    protected CompleteFuture(EventExecutor executor) {
+        this.executor = executor;
+    }
+
+    /**
+     * Return the {@link EventExecutor} which is used by this {@link CompleteFuture}.
+     */
+    protected EventExecutor executor() {
+        return executor;
+    }
+
+    @Override
+    public Future<V> addListener(GenericFutureListener<? extends Future<? super V>> listener) {
+        DefaultPromise.notifyListener(executor(), this, Objects.requireNonNull(listener, "listener"));
+        return this;
+    }
+
+    @Override
+    public Future<V> addListeners(GenericFutureListener<? extends Future<? super V>>... listeners) {
+        for (GenericFutureListener<? extends Future<? super V>> l:
+                Objects.requireNonNull(listeners, "listeners")) {
+
+            if (l == null) {
+                break;
+            }
+            DefaultPromise.notifyListener(executor(), this, l);
+        }
+        return this;
+    }
+
+    @Override
+    public Future<V> removeListener(GenericFutureListener<? extends Future<? super V>> listener) {
+        // NOOP
+        return this;
+    }
+
+    @Override
+    public Future<V> removeListeners(GenericFutureListener<? extends Future<? super V>>... listeners) {
+        // NOOP
+        return this;
+    }
+
+    @Override
+    public Future<V> await() throws InterruptedException {
+        if (Thread.interrupted()) {
+            throw new InterruptedException();
+        }
+        return this;
+    }
+
+    @Override
+    public boolean await(long timeout, TimeUnit unit) throws InterruptedException {
+        if (Thread.interrupted()) {
+            throw new InterruptedException();
+        }
+        return true;
+    }
+
+    @Override
+    public Future<V> sync() throws InterruptedException {
+        return this;
+    }
+
+    @Override
+    public Future<V> syncUninterruptibly() {
+        return this;
+    }
+
+    @Override
+    public boolean await(long timeoutMillis) throws InterruptedException {
+        if (Thread.interrupted()) {
+            throw new InterruptedException();
+        }
+        return true;
+    }
+
+    @Override
+    public Future<V> awaitUninterruptibly() {
+        return this;
+    }
+
+    @Override
+    public boolean awaitUninterruptibly(long timeout, TimeUnit unit) {
+        return true;
+    }
+
+    @Override
+    public boolean awaitUninterruptibly(long timeoutMillis) {
+        return true;
+    }
+
+    @Override
+    public boolean isDone() {
+        return true;
+    }
+
+    @Override
+    public boolean isCancellable() {
+        return false;
+    }
+
+    @Override
+    public boolean isCancelled() {
+        return false;
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * @param mayInterruptIfRunning this value has no effect in this implementation.
+     */
+    @Override
+    public boolean cancel(boolean mayInterruptIfRunning) {
+        return false;
+    }
+}

src/main/java/org/xbib/event/DefaultFutureListeners.java

@@ -0,0 +1,71 @@
+package org.xbib.event;
+
+import java.util.Arrays;
+
+final class DefaultFutureListeners {
+
+    private GenericFutureListener<? extends Future<?>>[] listeners;
+    private int size;
+    private int progressiveSize; // the number of progressive listeners
+
+    @SuppressWarnings("unchecked")
+    DefaultFutureListeners(
+            GenericFutureListener<? extends Future<?>> first, GenericFutureListener<? extends Future<?>> second) {
+        listeners = new GenericFutureListener[2];
+        listeners[0] = first;
+        listeners[1] = second;
+        size = 2;
+        if (first instanceof GenericProgressiveFutureListener) {
+            progressiveSize ++;
+        }
+        if (second instanceof GenericProgressiveFutureListener) {
+            progressiveSize ++;
+        }
+    }
+
+    public void add(GenericFutureListener<? extends Future<?>> l) {
+        GenericFutureListener<? extends Future<?>>[] listeners = this.listeners;
+        final int size = this.size;
+        if (size == listeners.length) {
+            this.listeners = listeners = Arrays.copyOf(listeners, size << 1);
+        }
+        listeners[size] = l;
+        this.size = size + 1;
+
+        if (l instanceof GenericProgressiveFutureListener) {
+            progressiveSize ++;
+        }
+    }
+
+    public void remove(GenericFutureListener<? extends Future<?>> l) {
+        final GenericFutureListener<? extends Future<?>>[] listeners = this.listeners;
+        int size = this.size;
+        for (int i = 0; i < size; i ++) {
+            if (listeners[i] == l) {
+                int listenersToMove = size - i - 1;
+                if (listenersToMove > 0) {
+                    System.arraycopy(listeners, i + 1, listeners, i, listenersToMove);
+                }
+                listeners[-- size] = null;
+                this.size = size;
+
+                if (l instanceof GenericProgressiveFutureListener) {
+                    progressiveSize --;
+                }
+                return;
+            }
+        }
+    }
+
+    public GenericFutureListener<? extends Future<?>>[] listeners() {
+        return listeners;
+    }
+
+    public int size() {
+        return size;
+    }
+
+    public int progressiveSize() {
+        return progressiveSize;
+    }
+}

src/main/java/org/xbib/event/DefaultProgressivePromise.java

@@ -0,0 +1,116 @@
+package org.xbib.event;
+
+import org.xbib.event.loop.EventExecutor;
+
+public class DefaultProgressivePromise<V> extends DefaultPromise<V> implements ProgressivePromise<V> {
+
+    /**
+     * Creates a new instance.
+     *
+     * It is preferable to use {@link EventExecutor#newProgressivePromise()} to create a new progressive promise
+     *
+     * @param executor
+     *        the {@link EventExecutor} which is used to notify the promise when it progresses or it is complete
+     */
+    public DefaultProgressivePromise(EventExecutor executor) {
+        super(executor);
+    }
+
+    protected DefaultProgressivePromise() { /* only for subclasses */ }
+
+    @Override
+    public ProgressivePromise<V> setProgress(long progress, long total) {
+        if (total < 0) {
+            // total unknown
+            total = -1; // normalize
+            if (progress < 0) {
+                throw new IllegalArgumentException("progress must not be less than zero");
+            }
+        } else if (progress < 0 || progress > total) {
+            throw new IllegalArgumentException(
+                    "progress: " + progress + " (expected: 0 <= progress <= total (" + total + "))");
+        }
+
+        if (isDone()) {
+            throw new IllegalStateException("complete already");
+        }
+
+        notifyProgressiveListeners(progress, total);
+        return this;
+    }
+
+    @Override
+    public boolean tryProgress(long progress, long total) {
+        if (total < 0) {
+            total = -1;
+            if (progress < 0 || isDone()) {
+                return false;
+            }
+        } else if (progress < 0 || progress > total || isDone()) {
+            return false;
+        }
+
+        notifyProgressiveListeners(progress, total);
+        return true;
+    }
+
+    @Override
+    public ProgressivePromise<V> addListener(GenericFutureListener<? extends Future<? super V>> listener) {
+        super.addListener(listener);
+        return this;
+    }
+
+    @Override
+    public ProgressivePromise<V> addListeners(GenericFutureListener<? extends Future<? super V>>... listeners) {
+        super.addListeners(listeners);
+        return this;
+    }
+
+    @Override
+    public ProgressivePromise<V> removeListener(GenericFutureListener<? extends Future<? super V>> listener) {
+        super.removeListener(listener);
+        return this;
+    }
+
+    @Override
+    public ProgressivePromise<V> removeListeners(GenericFutureListener<? extends Future<? super V>>... listeners) {
+        super.removeListeners(listeners);
+        return this;
+    }
+
+    @Override
+    public ProgressivePromise<V> sync() throws InterruptedException {
+        super.sync();
+        return this;
+    }
+
+    @Override
+    public ProgressivePromise<V> syncUninterruptibly() {
+        super.syncUninterruptibly();
+        return this;
+    }
+
+    @Override
+    public ProgressivePromise<V> await() throws InterruptedException {
+        super.await();
+        return this;
+    }
+
+    @Override
+    public ProgressivePromise<V> awaitUninterruptibly() {
+        super.awaitUninterruptibly();
+        return this;
+    }
+
+    @Override
+    public ProgressivePromise<V> setSuccess(V result) {
+        super.setSuccess(result);
+        return this;
+    }
+
+    @Override
+    public ProgressivePromise<V> setFailure(Throwable cause) {
+        super.setFailure(cause);
+        return this;
+    }
+}

src/main/java/org/xbib/event/DefaultPromise.java

@@ -0,0 +1,854 @@
+package org.xbib.event;
+
+import org.xbib.event.loop.BlockingOperationException;
+import org.xbib.event.loop.EventExecutor;
+import org.xbib.event.thread.InternalThreadLocalMap;
+
+import java.util.Objects;
+import java.util.concurrent.CancellationException;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import static java.util.concurrent.TimeUnit.MILLISECONDS;
+
+public class DefaultPromise<V> extends AbstractFuture<V> implements Promise<V> {
+    private static final Logger logger = Logger.getLogger(DefaultPromise.class.getName());
+    private static final Logger rejectedExecutionLogger =
+            Logger.getLogger(DefaultPromise.class.getName() + ".rejectedExecution");
+    private static final int MAX_LISTENER_STACK_DEPTH = Math.min(8,
+            Integer.getInteger("org.xbib.defaultPromise.maxListenerStackDepth", 8));
+    @SuppressWarnings("rawtypes")
+    private static final AtomicReferenceFieldUpdater<DefaultPromise, Object> RESULT_UPDATER =
+            AtomicReferenceFieldUpdater.newUpdater(DefaultPromise.class, Object.class, "result");
+    private static final Object SUCCESS = new Object();
+    private static final Object UNCANCELLABLE = new Object();
+    private static final CauseHolder CANCELLATION_CAUSE_HOLDER = new CauseHolder(
+            StacklessCancellationException.newInstance(DefaultPromise.class, "cancel(...)"));
+    private static final StackTraceElement[] CANCELLATION_STACK = CANCELLATION_CAUSE_HOLDER.cause.getStackTrace();
+
+    private volatile Object result;
+    private final EventExecutor executor;
+    /**
+     * One or more listeners. Can be a {@link GenericFutureListener} or a {@link DefaultFutureListeners}.
+     * If {@code null}, it means either 1) no listeners were added yet or 2) all listeners were notified.
+     *
+     * Threading - synchronized(this). We must support adding listeners when there is no EventExecutor.
+     */
+    private Object listeners;
+    /**
+     * Threading - synchronized(this). We are required to hold the monitor to use Java's underlying wait()/notifyAll().
+     */
+    private short waiters;
+
+    /**
+     * Threading - synchronized(this). We must prevent concurrent notification and FIFO listener notification if the
+     * executor changes.
+     */
+    private boolean notifyingListeners;
+
+    /**
+     * Creates a new instance.
+     *
+     * It is preferable to use {@link EventExecutor#newPromise()} to create a new promise
+     *
+     * @param executor
+     *        the {@link EventExecutor} which is used to notify the promise once it is complete.
+     *        It is assumed this executor will protect against {@link StackOverflowError} exceptions.
+     *        The executor may be used to avoid {@link StackOverflowError} by executing a {@link Runnable} if the stack
+     *        depth exceeds a threshold.
+     *
+     */
+    public DefaultPromise(EventExecutor executor) {
+        this.executor = Objects.requireNonNull(executor, "executor");
+    }
+
+    /**
+     * See {@link #executor()} for expectations of the executor.
+     */
+    protected DefaultPromise() {
+        // only for subclasses
+        executor = null;
+    }
+
+    @Override
+    public Promise<V> setSuccess(V result) {
+        if (setSuccess0(result)) {
+            return this;
+        }
+        throw new IllegalStateException("complete already: " + this);
+    }
+
+    @Override
+    public boolean trySuccess(V result) {
+        return setSuccess0(result);
+    }
+
+    @Override
+    public Promise<V> setFailure(Throwable cause) {
+        if (setFailure0(cause)) {
+            return this;
+        }
+        throw new IllegalStateException("complete already: " + this, cause);
+    }
+
+    @Override
+    public boolean tryFailure(Throwable cause) {
+        return setFailure0(cause);
+    }
+
+    @Override
+    public boolean setUncancellable() {
+        if (RESULT_UPDATER.compareAndSet(this, null, UNCANCELLABLE)) {
+            return true;
+        }
+        Object result = this.result;
+        return !isDone0(result) || !isCancelled0(result);
+    }
+
+    @Override
+    public boolean isSuccess() {
+        Object result = this.result;
+        return result != null && result != UNCANCELLABLE && !(result instanceof CauseHolder);
+    }
+
+    @Override
+    public boolean isCancellable() {
+        return result == null;
+    }
+
+    private static final class LeanCancellationException extends CancellationException {
+        private static final long serialVersionUID = 2794674970981187807L;
+
+        // Suppress a warning since the method doesn't need synchronization
+        @Override
+        public Throwable fillInStackTrace() {   // lgtm[java/non-sync-override]
+            setStackTrace(CANCELLATION_STACK);
+            return this;
+        }
+
+        @Override
+        public String toString() {
+            return CancellationException.class.getName();
+        }
+    }
+
+    @Override
+    public Throwable cause() {
+        return cause0(result);
+    }
+
+    private Throwable cause0(Object result) {
+        if (!(result instanceof CauseHolder)) {
+            return null;
+        }
+        if (result == CANCELLATION_CAUSE_HOLDER) {
+            CancellationException ce = new LeanCancellationException();
+            if (RESULT_UPDATER.compareAndSet(this, CANCELLATION_CAUSE_HOLDER, new CauseHolder(ce))) {
+                return ce;
+            }
+            result = this.result;
+        }
+        return ((CauseHolder) result).cause;
+    }
+
+    @Override
+    public Promise<V> addListener(GenericFutureListener<? extends Future<? super V>> listener) {
+        Objects.requireNonNull(listener, "listener");
+
+        synchronized (this) {
+            addListener0(listener);
+        }
+
+        if (isDone()) {
+            notifyListeners();
+        }
+
+        return this;
+    }
+
+    @Override
+    public Promise<V> addListeners(GenericFutureListener<? extends Future<? super V>>... listeners) {
+        Objects.requireNonNull(listeners, "listeners");
+
+        synchronized (this) {
+            for (GenericFutureListener<? extends Future<? super V>> listener : listeners) {
+                if (listener == null) {
+                    break;
+                }
+                addListener0(listener);
+            }
+        }
+
+        if (isDone()) {
+            notifyListeners();
+        }
+
+        return this;
+    }
+
+    @Override
+    public Promise<V> removeListener(final GenericFutureListener<? extends Future<? super V>> listener) {
+        Objects.requireNonNull(listener, "listener");
+
+        synchronized (this) {
+            removeListener0(listener);
+        }
+
+        return this;
+    }
+
+    @Override
+    public Promise<V> removeListeners(final GenericFutureListener<? extends Future<? super V>>... listeners) {
+        Objects.requireNonNull(listeners, "listeners");
+
+        synchronized (this) {
+            for (GenericFutureListener<? extends Future<? super V>> listener : listeners) {
+                if (listener == null) {
+                    break;
+                }
+                removeListener0(listener);
+            }
+        }
+
+        return this;
+    }
+
+    @Override
+    public Promise<V> await() throws InterruptedException {
+        if (isDone()) {
+            return this;
+        }
+
+        if (Thread.interrupted()) {
+            throw new InterruptedException(toString());
+        }
+
+        checkDeadLock();
+
+        synchronized (this) {
+            while (!isDone()) {
+                incWaiters();
+                try {
+                    wait();
+                } finally {
+                    decWaiters();
+                }
+            }
+        }
+        return this;
+    }
+
+    @Override
+    public Promise<V> awaitUninterruptibly() {
+        if (isDone()) {
+            return this;
+        }
+
+        checkDeadLock();
+
+        boolean interrupted = false;
+        synchronized (this) {
+            while (!isDone()) {
+                incWaiters();
+                try {
+                    wait();
+                } catch (InterruptedException e) {
+                    // Interrupted while waiting.
+                    interrupted = true;
+                } finally {
+                    decWaiters();
+                }
+            }
+        }
+
+        if (interrupted) {
+            Thread.currentThread().interrupt();
+        }
+
+        return this;
+    }
+
+    @Override
+    public boolean await(long timeout, TimeUnit unit) throws InterruptedException {
+        return await0(unit.toNanos(timeout), true);
+    }
+
+    @Override
+    public boolean await(long timeoutMillis) throws InterruptedException {
+        return await0(MILLISECONDS.toNanos(timeoutMillis), true);
+    }
+
+    @Override
+    public boolean awaitUninterruptibly(long timeout, TimeUnit unit) {
+        try {
+            return await0(unit.toNanos(timeout), false);
+        } catch (InterruptedException e) {
+            // Should not be raised at all.
+            throw new InternalError();
+        }
+    }
+
+    @Override
+    public boolean awaitUninterruptibly(long timeoutMillis) {
+        try {
+            return await0(MILLISECONDS.toNanos(timeoutMillis), false);
+        } catch (InterruptedException e) {
+            // Should not be raised at all.
+            throw new InternalError();
+        }
+    }
+
+    @SuppressWarnings("unchecked")
+    @Override
+    public V getNow() {
+        Object result = this.result;
+        if (result instanceof CauseHolder || result == SUCCESS || result == UNCANCELLABLE) {
+            return null;
+        }
+        return (V) result;
+    }
+
+    @SuppressWarnings("unchecked")
+    @Override
+    public V get() throws InterruptedException, ExecutionException {
+        Object result = this.result;
+        if (!isDone0(result)) {
+            await();
+            result = this.result;
+        }
+        if (result == SUCCESS || result == UNCANCELLABLE) {
+            return null;
+        }
+        Throwable cause = cause0(result);
+        if (cause == null) {
+            return (V) result;
+        }
+        if (cause instanceof CancellationException) {
+            throw (CancellationException) cause;
+        }
+        throw new ExecutionException(cause);
+    }
+
+    @SuppressWarnings("unchecked")
+    @Override
+    public V get(long timeout, TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException {
+        Object result = this.result;
+        if (!isDone0(result)) {
+            if (!await(timeout, unit)) {
+                throw new TimeoutException();
+            }
+            result = this.result;
+        }
+        if (result == SUCCESS || result == UNCANCELLABLE) {
+            return null;
+        }
+        Throwable cause = cause0(result);
+        if (cause == null) {
+            return (V) result;
+        }
+        if (cause instanceof CancellationException) {
+            throw (CancellationException) cause;
+        }
+        throw new ExecutionException(cause);
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * @param mayInterruptIfRunning this value has no effect in this implementation.
+     */
+    @Override
+    public boolean cancel(boolean mayInterruptIfRunning) {
+        if (RESULT_UPDATER.compareAndSet(this, null, CANCELLATION_CAUSE_HOLDER)) {
+            if (checkNotifyWaiters()) {
+                notifyListeners();
+            }
+            return true;
+        }
+        return false;
+    }
+
+    @Override
+    public boolean isCancelled() {
+        return isCancelled0(result);
+    }
+
+    @Override
+    public boolean isDone() {
+        return isDone0(result);
+    }
+
+    @Override
+    public Promise<V> sync() throws InterruptedException {
+        await();
+        rethrowIfFailed();
+        return this;
+    }
+
+    @Override
+    public Promise<V> syncUninterruptibly() {
+        awaitUninterruptibly();
+        rethrowIfFailed();
+        return this;
+    }
+
+    @Override
+    public String toString() {
+        return toStringBuilder().toString();
+    }
+
+    protected StringBuilder toStringBuilder() {
+        StringBuilder buf = new StringBuilder(64)
+                .append(getClass().getSimpleName())
+                .append('@')
+                .append(Integer.toHexString(hashCode()));
+
+        Object result = this.result;
+        if (result == SUCCESS) {
+            buf.append("(success)");
+        } else if (result == UNCANCELLABLE) {
+            buf.append("(uncancellable)");
+        } else if (result instanceof CauseHolder) {
+            buf.append("(failure: ")
+                    .append(((CauseHolder) result).cause)
+                    .append(')');
+        } else if (result != null) {
+            buf.append("(success: ")
+                    .append(result)
+                    .append(')');
+        } else {
+            buf.append("(incomplete)");
+        }
+
+        return buf;
+    }
+
+    /**
+     * Get the executor used to notify listeners when this promise is complete.
+     * <p>
+     * It is assumed this executor will protect against {@link StackOverflowError} exceptions.
+     * The executor may be used to avoid {@link StackOverflowError} by executing a {@link Runnable} if the stack
+     * depth exceeds a threshold.
+     * @return The executor used to notify listeners when this promise is complete.
+     */
+    protected EventExecutor executor() {
+        return executor;
+    }
+
+    protected void checkDeadLock() {
+        EventExecutor e = executor();
+        if (e != null && e.inEventLoop()) {
+            throw new BlockingOperationException(toString());
+        }
+    }
+
+    /**
+     * Notify a listener that a future has completed.
+     * <p>
+     * This method has a fixed depth of {@link #MAX_LISTENER_STACK_DEPTH} that will limit recursion to prevent
+     * {@link StackOverflowError} and will stop notifying listeners added after this threshold is exceeded.
+     * @param eventExecutor the executor to use to notify the listener {@code listener}.
+     * @param future the future that is complete.
+     * @param listener the listener to notify.
+     */
+    protected static void notifyListener(
+            EventExecutor eventExecutor, final Future<?> future, final GenericFutureListener<?> listener) {
+        notifyListenerWithStackOverFlowProtection(
+                Objects.requireNonNull(eventExecutor, "eventExecutor"),
+                Objects.requireNonNull(future, "future"),
+                Objects.requireNonNull(listener, "listener"));
+    }
+
+    private void notifyListeners() {
+        EventExecutor executor = executor();
+        if (executor.inEventLoop()) {
+            final InternalThreadLocalMap threadLocals = InternalThreadLocalMap.get();
+            final int stackDepth = threadLocals.futureListenerStackDepth();
+            if (stackDepth < MAX_LISTENER_STACK_DEPTH) {
+                threadLocals.setFutureListenerStackDepth(stackDepth + 1);
+                try {
+                    notifyListenersNow();
+                } finally {
+                    threadLocals.setFutureListenerStackDepth(stackDepth);
+                }
+                return;
+            }
+        }
+
+        safeExecute(executor, new Runnable() {
+            @Override
+            public void run() {
+                notifyListenersNow();
+            }
+        });
+    }
+
+    /**
+     * The logic in this method should be identical to {@link #notifyListeners()} but
+     * cannot share code because the listener(s) cannot be cached for an instance of {@link DefaultPromise} since the
+     * listener(s) may be changed and is protected by a synchronized operation.
+     */
+    private static void notifyListenerWithStackOverFlowProtection(final EventExecutor executor,
+                                                                  final Future<?> future,
+                                                                  final GenericFutureListener<?> listener) {
+        if (executor.inEventLoop()) {
+            final InternalThreadLocalMap threadLocals = InternalThreadLocalMap.get();
+            final int stackDepth = threadLocals.futureListenerStackDepth();
+            if (stackDepth < MAX_LISTENER_STACK_DEPTH) {
+                threadLocals.setFutureListenerStackDepth(stackDepth + 1);
+                try {
+                    notifyListener0(future, listener);
+                } finally {
+                    threadLocals.setFutureListenerStackDepth(stackDepth);
+                }
+                return;
+            }
+        }
+
+        safeExecute(executor, new Runnable() {
+            @Override
+            public void run() {
+                notifyListener0(future, listener);
+            }
+        });
+    }
+
+    private void notifyListenersNow() {
+        Object listeners;
+        synchronized (this) {
+            // Only proceed if there are listeners to notify and we are not already notifying listeners.
+            if (notifyingListeners || this.listeners == null) {
+                return;
+            }
+            notifyingListeners = true;
+            listeners = this.listeners;
+            this.listeners = null;
+        }
+        for (;;) {
+            if (listeners instanceof DefaultFutureListeners) {
+                notifyListeners0((DefaultFutureListeners) listeners);
+            } else {
+                notifyListener0(this, (GenericFutureListener<?>) listeners);
+            }
+            synchronized (this) {
+                if (this.listeners == null) {
+                    // Nothing can throw from within this method, so setting notifyingListeners back to false does not
+                    // need to be in a finally block.
+                    notifyingListeners = false;
+                    return;
+                }
+                listeners = this.listeners;
+                this.listeners = null;
+            }
+        }
+    }
+
+    private void notifyListeners0(DefaultFutureListeners listeners) {
+        GenericFutureListener<?>[] a = listeners.listeners();
+        int size = listeners.size();
+        for (int i = 0; i < size; i ++) {
+            notifyListener0(this, a[i]);
+        }
+    }
+
+    @SuppressWarnings({ "unchecked", "rawtypes" })
+    private static void notifyListener0(Future future, GenericFutureListener l) {
+        try {
+            l.operationComplete(future);
+        } catch (Throwable t) {
+            if (logger.isLoggable(Level.WARNING)) {
+                logger.log(Level.WARNING, "An exception was thrown by " + l.getClass().getName() + ".operationComplete()", t);
+            }
+        }
+    }
+
+    private void addListener0(GenericFutureListener<? extends Future<? super V>> listener) {
+        if (listeners == null) {
+            listeners = listener;
+        } else if (listeners instanceof DefaultFutureListeners) {
+            ((DefaultFutureListeners) listeners).add(listener);
+        } else {
+            listeners = new DefaultFutureListeners((GenericFutureListener<?>) listeners, listener);
+        }
+    }
+
+    private void removeListener0(GenericFutureListener<? extends Future<? super V>> listener) {
+        if (listeners instanceof DefaultFutureListeners) {
+            ((DefaultFutureListeners) listeners).remove(listener);
+        } else if (listeners == listener) {
+            listeners = null;
+        }
+    }
+
+    private boolean setSuccess0(V result) {
+        return setValue0(result == null ? SUCCESS : result);
+    }
+
+    private boolean setFailure0(Throwable cause) {
+        return setValue0(new CauseHolder(Objects.requireNonNull(cause, "cause")));
+    }
+
+    private boolean setValue0(Object objResult) {
+        if (RESULT_UPDATER.compareAndSet(this, null, objResult) ||
+            RESULT_UPDATER.compareAndSet(this, UNCANCELLABLE, objResult)) {
+            if (checkNotifyWaiters()) {
+                notifyListeners();
+            }
+            return true;
+        }
+        return false;
+    }
+
+    /**
+     * Check if there are any waiters and if so notify these.
+     * @return {@code true} if there are any listeners attached to the promise, {@code false} otherwise.
+     */
+    private synchronized boolean checkNotifyWaiters() {
+        if (waiters > 0) {
+            notifyAll();
+        }
+        return listeners != null;
+    }
+
+    private void incWaiters() {
+        if (waiters == Short.MAX_VALUE) {
+            throw new IllegalStateException("too many waiters: " + this);
+        }
+        ++waiters;
+    }
+
+    private void decWaiters() {
+        --waiters;
+    }
+
+    private void rethrowIfFailed() {
+        Throwable cause = cause();
+        if (cause == null) {
+            return;
+        }
+        throw new RuntimeException(cause);
+    }
+
+    private boolean await0(long timeoutNanos, boolean interruptable) throws InterruptedException {
+        if (isDone()) {
+            return true;
+        }
+
+        if (timeoutNanos <= 0) {
+            return isDone();
+        }
+
+        if (interruptable && Thread.interrupted()) {
+            throw new InterruptedException(toString());
+        }
+
+        checkDeadLock();
+
+        long startTime = System.nanoTime();
+        long waitTime = timeoutNanos;
+        boolean interrupted = false;
+        try {
+            for (;;) {
+                synchronized (this) {
+                    if (isDone()) {
+                        return true;
+                    }
+                    incWaiters();
+                    try {
+                        wait(waitTime / 1000000, (int) (waitTime % 1000000));
+                    } catch (InterruptedException e) {
+                        if (interruptable) {
+                            throw e;
+                        } else {
+                            interrupted = true;
+                        }
+                    } finally {
+                        decWaiters();
+                    }
+                }
+                if (isDone()) {
+                    return true;
+                } else {
+                    waitTime = timeoutNanos - (System.nanoTime() - startTime);
+                    if (waitTime <= 0) {
+                        return isDone();
+                    }
+                }
+            }
+        } finally {
+            if (interrupted) {
+                Thread.currentThread().interrupt();
+            }
+        }
+    }
+
+    /**
+     * Notify all progressive listeners.
+     * <p>
+     * No attempt is made to ensure notification order if multiple calls are made to this method before
+     * the original invocation completes.
+     * <p>
+     * This will do an iteration over all listeners to get all of type {@link GenericProgressiveFutureListener}s.
+     * @param progress the new progress.
+     * @param total the total progress.
+     */
+    @SuppressWarnings("unchecked")
+    void notifyProgressiveListeners(final long progress, final long total) {
+        final Object listeners = progressiveListeners();
+        if (listeners == null) {
+            return;
+        }
+
+        final ProgressiveFuture<V> self = (ProgressiveFuture<V>) this;
+
+        EventExecutor executor = executor();
+        if (executor.inEventLoop()) {
+            if (listeners instanceof GenericProgressiveFutureListener[]) {
+                notifyProgressiveListeners0(
+                        self, (GenericProgressiveFutureListener<?>[]) listeners, progress, total);
+            } else {
+                notifyProgressiveListener0(
+                        self, (GenericProgressiveFutureListener<ProgressiveFuture<V>>) listeners, progress, total);
+            }
+        } else {
+            if (listeners instanceof GenericProgressiveFutureListener[]) {
+                final GenericProgressiveFutureListener<?>[] array =
+                        (GenericProgressiveFutureListener<?>[]) listeners;
+                safeExecute(executor, new Runnable() {
+                    @Override
+                    public void run() {
+                        notifyProgressiveListeners0(self, array, progress, total);
+                    }
+                });
+            } else {
+                final GenericProgressiveFutureListener<ProgressiveFuture<V>> l =
+                        (GenericProgressiveFutureListener<ProgressiveFuture<V>>) listeners;
+                safeExecute(executor, new Runnable() {
+                    @Override
+                    public void run() {
+                        notifyProgressiveListener0(self, l, progress, total);
+                    }
+                });
+            }
+        }
+    }
+
+    /**
+     * Returns a {@link GenericProgressiveFutureListener}, an array of {@link GenericProgressiveFutureListener}, or
+     * {@code null}.
+     */
+    private synchronized Object progressiveListeners() {
+        Object listeners = this.listeners;
+        if (listeners == null) {
+            // No listeners added
+            return null;
+        }
+
+        if (listeners instanceof DefaultFutureListeners) {
+            // Copy DefaultFutureListeners into an array of listeners.
+            DefaultFutureListeners dfl = (DefaultFutureListeners) listeners;
+            int progressiveSize = dfl.progressiveSize();
+            switch (progressiveSize) {
+                case 0:
+                    return null;
+                case 1:
+                    for (GenericFutureListener<?> l: dfl.listeners()) {
+                        if (l instanceof GenericProgressiveFutureListener) {
+                            return l;
+                        }
+                    }
+                    return null;
+            }
+
+            GenericFutureListener<?>[] array = dfl.listeners();
+            GenericProgressiveFutureListener<?>[] copy = new GenericProgressiveFutureListener[progressiveSize];
+            for (int i = 0, j = 0; j < progressiveSize; i ++) {
+                GenericFutureListener<?> l = array[i];
+                if (l instanceof GenericProgressiveFutureListener) {
+                    copy[j ++] = (GenericProgressiveFutureListener<?>) l;
+                }
+            }
+
+            return copy;
+        } else if (listeners instanceof GenericProgressiveFutureListener) {
+            return listeners;
+        } else {
+            // Only one listener was added and it's not a progressive listener.
+            return null;
+        }
+    }
+
+    private static void notifyProgressiveListeners0(
+            ProgressiveFuture<?> future, GenericProgressiveFutureListener<?>[] listeners, long progress, long total) {
+        for (GenericProgressiveFutureListener<?> l: listeners) {
+            if (l == null) {
+                break;
+            }
+            notifyProgressiveListener0(future, l, progress, total);
+        }
+    }
+
+    @SuppressWarnings({ "unchecked", "rawtypes" })
+    private static void notifyProgressiveListener0(
+            ProgressiveFuture future, GenericProgressiveFutureListener l, long progress, long total) {
+        try {
+            l.operationProgressed(future, progress, total);
+        } catch (Throwable t) {
+            if (logger.isLoggable(Level.WARNING)) {
+                logger.log(Level.WARNING, "An exception was thrown by " + l.getClass().getName() + ".operationProgressed()", t);
+            }
+        }
+    }
+
+    private static boolean isCancelled0(Object result) {
+        return result instanceof CauseHolder && ((CauseHolder) result).cause instanceof CancellationException;
+    }
+
+    private static boolean isDone0(Object result) {
+        return result != null && result != UNCANCELLABLE;
+    }
+
+    private static final class CauseHolder {
+        final Throwable cause;
+        CauseHolder(Throwable cause) {
+            this.cause = cause;
+        }
+    }
+
+    private static void safeExecute(EventExecutor executor, Runnable task) {
+        try {
+            executor.execute(task);
+        } catch (Throwable t) {
+            rejectedExecutionLogger.log(Level.SEVERE, "Failed to submit a listener notification task. Event loop shut down?", t);
+        }
+    }
+
+    private static final class StacklessCancellationException extends CancellationException {
+
+        private StacklessCancellationException() { }
+
+        // Override fillInStackTrace() so we not populate the backtrace via a native call and so leak the
+        // Classloader.
+        @Override
+        public Throwable fillInStackTrace() {
+            return this;
+        }
+
+        static StacklessCancellationException newInstance(Class<?> clazz, String method) {
+            return unknownStackTrace(new StacklessCancellationException(), clazz, method);
+        }
+
+        /**
+         * Set the {@link StackTraceElement} for the given {@link Throwable}, using the {@link Class} and method name.
+         */
+        private static <T extends Throwable> T unknownStackTrace(T cause, Class<?> clazz, String method) {
+            cause.setStackTrace(new StackTraceElement[] { new StackTraceElement(clazz.getName(), method, null, -1)});
+            return cause;
+        }
+
+    }
+}

src/main/java/org/xbib/event/EventService.java

@@ -1,7 +0,0 @@
-package org.xbib.event;
-
-public class EventService {
-
-    public EventService() {
-    }
-}

src/main/java/org/xbib/event/FailedFuture.java

@@ -0,0 +1,51 @@
+package org.xbib.event;
+
+import org.xbib.event.loop.EventExecutor;
+
+import java.util.Objects;
+
+/**
+ * The {@link CompleteFuture} which is failed already.  It is
+ * recommended to use {@link EventExecutor#newFailedFuture(Throwable)}
+ * instead of calling the constructor of this future.
+ */
+public final class FailedFuture<V> extends CompleteFuture<V> {
+
+    private final Throwable cause;
+
+    /**
+     * Creates a new instance.
+     *
+     * @param executor the {@link EventExecutor} associated with this future
+     * @param cause   the cause of failure
+     */
+    public FailedFuture(EventExecutor executor, Throwable cause) {
+        super(executor);
+        this.cause = Objects.requireNonNull(cause, "cause");
+    }
+
+    @Override
+    public Throwable cause() {
+        return cause;
+    }
+
+    @Override
+    public boolean isSuccess() {
+        return false;
+    }
+
+    @Override
+    public Future<V> sync() {
+        throw new RuntimeException(cause);
+    }
+
+    @Override
+    public Future<V> syncUninterruptibly() {
+        throw new RuntimeException(cause);
+    }
+
+    @Override
+    public V getNow() {
+        return null;
+    }
+}

src/main/java/org/xbib/event/FileFollowEvent.java

@@ -1,7 +0,0 @@
-package org.xbib.event;
-
-public class FileFollowEvent {
-
-    public FileFollowEvent() {
-    }
-}

src/main/java/org/xbib/event/Future.java

@@ -0,0 +1,39 @@
+package org.xbib.event;
+
+import java.util.concurrent.TimeUnit;
+
+public interface Future<V> extends java.util.concurrent.Future<V> {
+    boolean isSuccess();
+
+    boolean isCancellable();
+
+    Throwable cause();
+
+    Future<V> addListener(GenericFutureListener<? extends Future<? super V>> var1);
+
+    Future<V> addListeners(GenericFutureListener<? extends Future<? super V>>... var1);
+
+    Future<V> removeListener(GenericFutureListener<? extends Future<? super V>> var1);
+
+    Future<V> removeListeners(GenericFutureListener<? extends Future<? super V>>... var1);
+
+    Future<V> sync() throws InterruptedException;
+
+    Future<V> syncUninterruptibly();
+
+    Future<V> await() throws InterruptedException;
+
+    Future<V> awaitUninterruptibly();
+
+    boolean await(long var1, TimeUnit var3) throws InterruptedException;
+
+    boolean await(long var1) throws InterruptedException;
+
+    boolean awaitUninterruptibly(long var1, TimeUnit var3);
+
+    boolean awaitUninterruptibly(long var1);
+
+    V getNow();
+
+    boolean cancel(boolean var1);
+}

src/main/java/org/xbib/event/FutureListener.java

@@ -0,0 +1,4 @@
+package org.xbib.event;
+
+public interface FutureListener<V> extends GenericFutureListener<Future<V>> {
+}

src/main/java/org/xbib/event/GenericFutureListener.java

@@ -0,0 +1,7 @@
+package org.xbib.event;
+
+import java.util.EventListener;
+
+public interface GenericFutureListener<F extends Future<?>> extends EventListener {
+    void operationComplete(F future) throws Exception;
+}

src/main/java/org/xbib/event/GenericProgressiveFutureListener.java

@@ -0,0 +1,12 @@
+package org.xbib.event;
+
+public interface GenericProgressiveFutureListener<F extends ProgressiveFuture<?>> extends GenericFutureListener<F> {
+    /**
+     * Invoked when the operation has progressed.
+     *
+     * @param progress the progress of the operation so far (cumulative)
+     * @param total the number that signifies the end of the operation when {@code progress} reaches at it.
+     *              {@code -1} if the end of operation is unknown.
+     */
+    void operationProgressed(F future, long progress, long total) throws Exception;
+}

src/main/java/org/xbib/event/ProgressiveFuture.java

@@ -0,0 +1,31 @@
+package org.xbib.event;
+
+/**
+ * A {@link Future} which is used to indicate the progress of an operation.
+ */
+public interface ProgressiveFuture<V> extends Future<V> {
+
+    @Override
+    ProgressiveFuture<V> addListener(GenericFutureListener<? extends Future<? super V>> listener);
+
+    @Override
+    ProgressiveFuture<V> addListeners(GenericFutureListener<? extends Future<? super V>>... listeners);
+
+    @Override
+    ProgressiveFuture<V> removeListener(GenericFutureListener<? extends Future<? super V>> listener);
+
+    @Override
+    ProgressiveFuture<V> removeListeners(GenericFutureListener<? extends Future<? super V>>... listeners);
+
+    @Override
+    ProgressiveFuture<V> sync() throws InterruptedException;
+
+    @Override
+    ProgressiveFuture<V> syncUninterruptibly();
+
+    @Override
+    ProgressiveFuture<V> await() throws InterruptedException;
+
+    @Override
+    ProgressiveFuture<V> awaitUninterruptibly();
+}

src/main/java/org/xbib/event/ProgressivePromise.java

@@ -0,0 +1,50 @@
+package org.xbib.event;
+
+/**
+ * Special {@link ProgressiveFuture} which is writable.
+ */
+public interface ProgressivePromise<V> extends Promise<V>, ProgressiveFuture<V> {
+
+    /**
+     * Sets the current progress of the operation and notifies the listeners that implement
+     * {@link GenericProgressiveFutureListener}.
+     */
+    ProgressivePromise<V> setProgress(long progress, long total);
+
+    /**
+     * Tries to set the current progress of the operation and notifies the listeners that implement
+     * {@link GenericProgressiveFutureListener}.  If the operation is already complete or the progress is out of range,
+     * this method does nothing but returning {@code false}.
+     */
+    boolean tryProgress(long progress, long total);
+
+    @Override
+    ProgressivePromise<V> setSuccess(V result);
+
+    @Override
+    ProgressivePromise<V> setFailure(Throwable cause);
+
+    @Override
+    ProgressivePromise<V> addListener(GenericFutureListener<? extends Future<? super V>> listener);
+
+    @Override
+    ProgressivePromise<V> addListeners(GenericFutureListener<? extends Future<? super V>>... listeners);
+
+    @Override
+    ProgressivePromise<V> removeListener(GenericFutureListener<? extends Future<? super V>> listener);
+
+    @Override
+    ProgressivePromise<V> removeListeners(GenericFutureListener<? extends Future<? super V>>... listeners);
+
+    @Override
+    ProgressivePromise<V> await() throws InterruptedException;
+
+    @Override
+    ProgressivePromise<V> awaitUninterruptibly();
+
+    @Override
+    ProgressivePromise<V> sync() throws InterruptedException;
+
+    @Override
+    ProgressivePromise<V> syncUninterruptibly();
+}

src/main/java/org/xbib/event/Promise.java

@@ -0,0 +1,29 @@
+package org.xbib.event;
+
+public interface Promise<V> extends Future<V> {
+    Promise<V> setSuccess(V value);
+
+    boolean trySuccess(V value);
+
+    Promise<V> setFailure(Throwable value);
+
+    boolean tryFailure(Throwable value);
+
+    boolean setUncancellable();
+
+    Promise<V> addListener(GenericFutureListener<? extends Future<? super V>> value);
+
+    Promise<V> addListeners(GenericFutureListener<? extends Future<? super V>>... value);
+
+    Promise<V> removeListener(GenericFutureListener<? extends Future<? super V>> value);
+
+    Promise<V> removeListeners(GenericFutureListener<? extends Future<? super V>>... value);
+
+    Promise<V> await() throws InterruptedException;
+
+    Promise<V> awaitUninterruptibly();
+
+    Promise<V> sync() throws InterruptedException;
+
+    Promise<V> syncUninterruptibly();
+}

src/main/java/org/xbib/event/PromiseTask.java

@@ -0,0 +1,175 @@
+package org.xbib.event;
+
+import org.xbib.event.loop.EventExecutor;
+
+import java.util.concurrent.Callable;
+import java.util.concurrent.RunnableFuture;
+
+public class PromiseTask<V> extends DefaultPromise<V> implements RunnableFuture<V> {
+
+    private static final class RunnableAdapter<T> implements Callable<T> {
+        final Runnable task;
+        final T result;
+
+        RunnableAdapter(Runnable task, T result) {
+            this.task = task;
+            this.result = result;
+        }
+
+        @Override
+        public T call() {
+            task.run();
+            return result;
+        }
+
+        @Override
+        public String toString() {
+            return "Callable(task: " + task + ", result: " + result + ')';
+        }
+    }
+
+    private static final Runnable COMPLETED = new SentinelRunnable("COMPLETED");
+    private static final Runnable CANCELLED = new SentinelRunnable("CANCELLED");
+    private static final Runnable FAILED = new SentinelRunnable("FAILED");
+
+    private static class SentinelRunnable implements Runnable {
+        private final String name;
+
+        SentinelRunnable(String name) {
+            this.name = name;
+        }
+
+        @Override
+        public void run() { } // no-op
+
+        @Override
+        public String toString() {
+            return name;
+        }
+    }
+
+    // Strictly of type Callable<V> or Runnable
+    private Object task;
+
+    public PromiseTask(EventExecutor executor, Runnable runnable, V result) {
+        super(executor);
+        task = result == null ? runnable : new RunnableAdapter<V>(runnable, result);
+    }
+
+    public PromiseTask(EventExecutor executor, Runnable runnable) {
+        super(executor);
+        task = runnable;
+    }
+
+    public PromiseTask(EventExecutor executor, Callable<V> callable) {
+        super(executor);
+        task = callable;
+    }
+
+    @Override
+    public final int hashCode() {
+        return System.identityHashCode(this);
+    }
+
+    @Override
+    public final boolean equals(Object obj) {
+        return this == obj;
+    }
+
+    @SuppressWarnings("unchecked")
+    V runTask() throws Throwable {
+        final Object task = this.task;
+        if (task instanceof Callable) {
+            return ((Callable<V>) task).call();
+        }
+        ((Runnable) task).run();
+        return null;
+    }
+
+    @Override
+    public void run() {
+        try {
+            if (setUncancellableInternal()) {
+                V result = runTask();
+                setSuccessInternal(result);
+            }
+        } catch (Throwable e) {
+            setFailureInternal(e);
+        }
+    }
+
+    private boolean clearTaskAfterCompletion(boolean done, Runnable result) {
+        if (done) {
+            // The only time where it might be possible for the sentinel task
+            // to be called is in the case of a periodic ScheduledFutureTask,
+            // in which case it's a benign race with cancellation and the (null)
+            // return value is not used.
+            task = result;
+        }
+        return done;
+    }
+
+    @Override
+    public final Promise<V> setFailure(Throwable cause) {
+        throw new IllegalStateException();
+    }
+
+    protected final Promise<V> setFailureInternal(Throwable cause) {
+        super.setFailure(cause);
+        clearTaskAfterCompletion(true, FAILED);
+        return this;
+    }
+
+    @Override
+    public final boolean tryFailure(Throwable cause) {
+        return false;
+    }
+
+    protected final boolean tryFailureInternal(Throwable cause) {
+        return clearTaskAfterCompletion(super.tryFailure(cause), FAILED);
+    }
+
+    @Override
+    public final Promise<V> setSuccess(V result) {
+        throw new IllegalStateException();
+    }
+
+    protected final Promise<V> setSuccessInternal(V result) {
+        super.setSuccess(result);
+        clearTaskAfterCompletion(true, COMPLETED);
+        return this;
+    }
+
+    @Override
+    public final boolean trySuccess(V result) {
+        return false;
+    }
+
+    protected final boolean trySuccessInternal(V result) {
+        return clearTaskAfterCompletion(super.trySuccess(result), COMPLETED);
+    }
+
+    @Override
+    public final boolean setUncancellable() {
+        throw new IllegalStateException();
+    }
+
+    protected final boolean setUncancellableInternal() {
+        return super.setUncancellable();
+    }
+
+    @Override
+    public boolean cancel(boolean mayInterruptIfRunning) {
+        return clearTaskAfterCompletion(super.cancel(mayInterruptIfRunning), CANCELLED);
+    }
+
+    @Override
+    protected StringBuilder toStringBuilder() {
+        StringBuilder buf = super.toStringBuilder();
+        buf.setCharAt(buf.length() - 1, ',');
+
+        return buf.append(" task: ")
+                  .append(task)
+                  .append(')');
+    }
+}

src/main/java/org/xbib/event/ScheduledFuture.java

@@ -0,0 +1,8 @@
+package org.xbib.event;
+
+/**
+ * The result of a scheduled asynchronous operation.
+ */
+@SuppressWarnings("ClassNameSameAsAncestorName")
+public interface ScheduledFuture<V> extends Future<V>, java.util.concurrent.ScheduledFuture<V> {
+}

src/main/java/org/xbib/event/ScheduledFutureTask.java

@@ -0,0 +1,223 @@
+package org.xbib.event;
+
+import org.xbib.event.loop.AbstractScheduledEventExecutor;
+import org.xbib.event.loop.EventExecutor;
+import org.xbib.event.util.DefaultPriorityQueue;
+import org.xbib.event.util.PriorityQueueNode;
+
+import java.util.concurrent.Callable;
+import java.util.concurrent.Delayed;
+import java.util.concurrent.TimeUnit;
+
+@SuppressWarnings("ComparableImplementedButEqualsNotOverridden")
+public final class ScheduledFutureTask<V> extends PromiseTask<V> implements ScheduledFuture<V>, PriorityQueueNode {
+    private static final long START_TIME = System.nanoTime();
+
+    public static long nanoTime() {
+        return System.nanoTime() - START_TIME;
+    }
+
+    public static long deadlineNanos(long delay) {
+        long deadlineNanos = nanoTime() + delay;
+        // Guard against overflow
+        return deadlineNanos < 0 ? Long.MAX_VALUE : deadlineNanos;
+    }
+
+    public static long initialNanoTime() {
+        return START_TIME;
+    }
+
+    // set once when added to priority queue
+    private long id;
+
+    private long deadlineNanos;
+    /* 0 - no repeat, >0 - repeat at fixed rate, <0 - repeat with fixed delay */
+    private final long periodNanos;
+
+    private int queueIndex = INDEX_NOT_IN_QUEUE;
+
+    public ScheduledFutureTask(AbstractScheduledEventExecutor executor,
+                               Runnable runnable, long nanoTime) {
+
+        super(executor, runnable);
+        deadlineNanos = nanoTime;
+        periodNanos = 0;
+    }
+
+    public ScheduledFutureTask(AbstractScheduledEventExecutor executor,
+            Runnable runnable, long nanoTime, long period) {
+
+        super(executor, runnable);
+        deadlineNanos = nanoTime;
+        periodNanos = validatePeriod(period);
+    }
+
+    public ScheduledFutureTask(AbstractScheduledEventExecutor executor,
+            Callable<V> callable, long nanoTime, long period) {
+
+        super(executor, callable);
+        deadlineNanos = nanoTime;
+        periodNanos = validatePeriod(period);
+    }
+
+    public ScheduledFutureTask(AbstractScheduledEventExecutor executor,
+            Callable<V> callable, long nanoTime) {
+
+        super(executor, callable);
+        deadlineNanos = nanoTime;
+        periodNanos = 0;
+    }
+
+    private static long validatePeriod(long period) {
+        if (period == 0) {
+            throw new IllegalArgumentException("period: 0 (expected: != 0)");
+        }
+        return period;
+    }
+
+    public ScheduledFutureTask<V> setId(long id) {
+        if (this.id == 0L) {
+            this.id = id;
+        }
+        return this;
+    }
+
+    @Override
+    protected EventExecutor executor() {
+        return super.executor();
+    }
+
+    public long deadlineNanos() {
+        return deadlineNanos;
+    }
+
+    public void setConsumed() {
+        // Optimization to avoid checking system clock again
+        // after deadline has passed and task has been dequeued
+        if (periodNanos == 0) {
+            assert nanoTime() >= deadlineNanos;
+            deadlineNanos = 0L;
+        }
+    }
+
+    public long delayNanos() {
+        return deadlineToDelayNanos(deadlineNanos());
+    }
+
+    public static long deadlineToDelayNanos(long deadlineNanos) {
+        return deadlineNanos == 0L ? 0L : Math.max(0L, deadlineNanos - nanoTime());
+    }
+
+    public long delayNanos(long currentTimeNanos) {
+        return deadlineNanos == 0L ? 0L
+                : Math.max(0L, deadlineNanos() - (currentTimeNanos - START_TIME));
+    }
+
+    @Override
+    public long getDelay(TimeUnit unit) {
+        return unit.convert(delayNanos(), TimeUnit.NANOSECONDS);
+    }
+
+    @Override
+    public int compareTo(Delayed o) {
+        if (this == o) {
+            return 0;
+        }
+
+        ScheduledFutureTask<?> that = (ScheduledFutureTask<?>) o;
+        long d = deadlineNanos() - that.deadlineNanos();
+        if (d < 0) {
+            return -1;
+        } else if (d > 0) {
+            return 1;
+        } else if (id < that.id) {
+            return -1;
+        } else {
+            assert id != that.id;
+            return 1;
+        }
+    }
+
+    @Override
+    public void run() {
+        assert executor().inEventLoop();
+        try {
+            if (delayNanos() > 0L) {
+                // Not yet expired, need to add or remove from queue
+                if (isCancelled()) {
+                    scheduledExecutor().scheduledTaskQueue().removeTyped(this);
+                } else {
+                    scheduledExecutor().scheduleFromEventLoop(this);
+                }
+                return;
+            }
+            if (periodNanos == 0) {
+                if (setUncancellableInternal()) {
+                    V result = runTask();
+                    setSuccessInternal(result);
+                }
+            } else {
+                // check if is done as it may was cancelled
+                if (!isCancelled()) {
+                    runTask();
+                    if (!executor().isShutdown()) {
+                        if (periodNanos > 0) {
+                            deadlineNanos += periodNanos;
+                        } else {
+                            deadlineNanos = nanoTime() - periodNanos;
+                        }
+                        if (!isCancelled()) {
+                            scheduledExecutor().scheduledTaskQueue().add(this);
+                        }
+                    }
+                }
+            }
+        } catch (Throwable cause) {
+            setFailureInternal(cause);
+        }
+    }
+
+    private AbstractScheduledEventExecutor scheduledExecutor() {
+        return (AbstractScheduledEventExecutor) executor();
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * @param mayInterruptIfRunning this value has no effect in this implementation.
+     */
+    @Override
+    public boolean cancel(boolean mayInterruptIfRunning) {
+        boolean canceled = super.cancel(mayInterruptIfRunning);
+        if (canceled) {
+            scheduledExecutor().removeScheduled(this);
+        }
+        return canceled;
+    }
+
+    public boolean cancelWithoutRemove(boolean mayInterruptIfRunning) {
+        return super.cancel(mayInterruptIfRunning);
+    }
+
+    @Override
+    protected StringBuilder toStringBuilder() {
+        StringBuilder buf = super.toStringBuilder();
+        buf.setCharAt(buf.length() - 1, ',');
+
+        return buf.append(" deadline: ")
+                  .append(deadlineNanos)
+                  .append(", period: ")
+                  .append(periodNanos)
+                  .append(')');
+    }
+
+    @Override
+    public int priorityQueueIndex(DefaultPriorityQueue<?> queue) {
+        return queueIndex;
+    }
+
+    @Override
+    public void priorityQueueIndex(DefaultPriorityQueue<?> queue, int i) {
+        queueIndex = i;
+    }
+}

src/main/java/org/xbib/event/SucceededFuture.java

@@ -0,0 +1,37 @@
+package org.xbib.event;
+
+import org.xbib.event.loop.EventExecutor;
+
+/**
+ * The {@link CompleteFuture} which is succeeded already.  It is
+ * recommended to use {@link EventExecutor#newSucceededFuture(Object)} instead of
+ * calling the constructor of this future.
+ */
+public final class SucceededFuture<V> extends CompleteFuture<V> {
+    private final V result;
+
+    /**
+     * Creates a new instance.
+     *
+     * @param executor the {@link EventExecutor} associated with this future
+     */
+    public SucceededFuture(EventExecutor executor, V result) {
+        super(executor);
+        this.result = result;
+    }
+
+    @Override
+    public Throwable cause() {
+        return null;
+    }
+
+    @Override
+    public boolean isSuccess() {
+        return true;
+    }
+
+    @Override
+    public V getNow() {
+        return result;
+    }
+}

src/main/java/org/xbib/event/async/Async.java

@@ -0,0 +1,189 @@
+package org.xbib.event.async;
+
+import org.xbib.event.async.impl.ContextInternal;
+import org.xbib.event.async.impl.AsyncBuilder;
+
+/**
+ * The entry point into the Async API.
+ *
+ */
+public interface Async {
+
+  /**
+   * Creates an instance using default options.
+   *
+   * @return the instance
+   */
+  static Async getInstance() {
+    return getInstance(new AsyncOptions());
+  }
+
+  /**
+   * Creates a non clustered instance using the specified options
+   *
+   * @param options  the options to use
+   * @return the instance
+   */
+  static Async getInstance(AsyncOptions options) {
+    return new AsyncBuilder(options).init().newInstance();
+  }
+
+  /**
+   * Gets the current context
+   *
+   * @return The current context or {@code null} if there is no current context
+   */
+  static Context currentContext() {
+    return ContextInternal.current();
+  }
+
+  /**
+   * Gets the current context, or creates one if there isn't one
+   *
+   * @return The current context (created if didn't exist)
+   */
+  Context getOrCreateContext();
+
+  /**
+   * Set a one-shot timer to fire after {@code delay} milliseconds, at which point {@code handler} will be called with
+   * the id of the timer.
+   *
+   * @param delay  the delay in milliseconds, after which the timer will fire
+   * @param handler  the handler that will be called with the timer ID when the timer fires
+   * @return the unique ID of the timer
+   */
+  long setTimer(long delay, Handler<Long> handler);
+
+  /**
+   * Returns a one-shot timer as a read stream.
+   *
+   * @param delay  the delay in milliseconds, after which the timer will fire
+   * @return the timer stream
+   */
+  TimeoutStream timerStream(long delay);
+
+  /**
+   * Set a periodic timer to fire every {@code delay} milliseconds, at which point {@code handler} will be called with
+   * the id of the timer.
+   *
+   * @param delay  the delay in milliseconds, after which the timer will fire
+   * @param handler  the handler that will be called with the timer ID when the timer fires
+   * @return the unique ID of the timer
+   */
+  default long setPeriodic(long delay, Handler<Long> handler) {
+    return setPeriodic(delay, delay, handler);
+  }
+
+  /**
+   * Set a periodic timer to fire every {@code delay} milliseconds with initial delay, at which point {@code handler} will be called with
+   * the id of the timer.
+   *
+   * @param initialDelay the initial delay in milliseconds
+   * @param delay the delay in milliseconds, after which the timer will fire
+   * @param handler the handler that will be called with the timer ID when the timer fires
+   * @return the unique ID of the timer
+   */
+  long setPeriodic(long initialDelay, long delay, Handler<Long> handler);
+
+  /**
+   * Returns a periodic timer as a read stream.
+   *
+   * @param delay  the delay in milliseconds, after which the timer will fire
+   * @return the periodic stream
+   */
+  default TimeoutStream periodicStream(long delay) {
+    return periodicStream(0, delay);
+  }
+
+  /**
+   * Returns a periodic timer as a read stream.
+   *
+   * @param initialDelay the initial delay in milliseconds
+   * @param delay the delay in milliseconds, after which the timer will fire
+   * @return the periodic stream
+   */
+  TimeoutStream periodicStream(long initialDelay, long delay);
+
+  /**
+   * Cancels the timer with the specified {@code id}.
+   *
+   * @param id  The id of the timer to cancel
+   * @return true if the timer was successfully cancelled, or false if the timer does not exist.
+   */
+  boolean cancelTimer(long id);
+
+  /**
+   * Puts the handler on the event queue for the current context so it will be run asynchronously ASAP after all
+   * preceeding events have been handled.
+   *
+   * @param action - a handler representing the action to execute
+   */
+  void runOnContext(Handler<Void> action);
+
+  /**
+   * Stop the Async instance and release any resources held by it.
+   * <p>
+   * The instance cannot be used after it has been closed.
+   * <p>
+   * The actual close is asynchronous and may not complete until after the call has returned.
+   *
+   * @return a future completed with the result
+   */
+  Future<Void> close();
+
+  /**
+   * Safely execute some blocking code.
+   * <p>
+   * Executes the blocking code in the handler {@code blockingCodeHandler} using a thread from the worker pool.
+   * <p>
+   * When the code is complete the handler {@code resultHandler} will be called with the result on the original context
+   * (e.g. on the original event loop of the caller).
+   * <p>
+   * A {@code Future} instance is passed into {@code blockingCodeHandler}. When the blocking code successfully completes,
+   * the handler should call the {@link Promise#complete} or {@link Promise#complete(Object)} method, or the {@link Promise#fail}
+   * method if it failed.
+   * <p>
+   * In the {@code blockingCodeHandler} the current context remains the original context and therefore any task
+   * scheduled in the {@code blockingCodeHandler} will be executed on the this context and not on the worker thread.
+   * <p>
+   * The blocking code should block for a reasonable amount of time (i.e no more than a few seconds). Long blocking operations
+   * or polling operations (i.e a thread that spin in a loop polling events in a blocking fashion) are precluded.
+   * <p>
+   * When the blocking operation lasts more than the 10 seconds, a message will be printed on the console by the
+   * blocked thread checker.
+   * <p>
+   * Long blocking operations should use a dedicated thread managed by the application, which can interact with
+   * subscribers using the event-bus or {@link Context#runOnContext(Handler)}
+   *
+   * @param blockingCodeHandler  handler representing the blocking code to run
+   * @param ordered  if true then if executeBlocking is called several times on the same context, the executions
+   *                 for that context will be executed serially, not in parallel. if false then they will be no ordering
+   *                 guarantees
+   * @param <T> the type of the result
+   * @return a future completed when the blocking code is complete
+   */
+  default <T> Future<T> executeBlocking(Handler<Promise<T>> blockingCodeHandler, boolean ordered) {
+    Context context = getOrCreateContext();
+    return context.executeBlocking(blockingCodeHandler, ordered);
+  }
+
+  /**
+   * Like {@link #executeBlocking(Handler, boolean)} called with ordered = true.
+   */
+  default <T> Future<T> executeBlocking(Handler<Promise<T>> blockingCodeHandler) {
+    return executeBlocking(blockingCodeHandler, true);
+  }
+
+  /**
+   * Set a default exception handler for {@link Context}, set on {@link Context#exceptionHandler(Handler)} at creation.
+   *
+   * @param handler the exception handler
+   * @return a reference to this, so the API can be used fluently
+   */
+  Async exceptionHandler(Handler<Throwable> handler);
+
+  /**
+   * @return the current default exception handler
+   */
+  Handler<Throwable> exceptionHandler();
+}

src/main/java/org/xbib/event/async/AsyncOptions.java

@@ -0,0 +1,447 @@
+package org.xbib.event.async;
+
+import java.util.concurrent.TimeUnit;
+
+/**
+ * Instances of this class are used to configure {@link Async} instances.
+ */
+public class AsyncOptions {
+
+  private static final String DISABLE_TCCL_PROP_NAME = "org.xbib.disableTCCL";
+
+  /**
+   * The default number of event loop threads to be used  = 2 * number of cores on the machine
+   */
+  public static final int DEFAULT_EVENT_LOOP_POOL_SIZE = 2 * Runtime.getRuntime().availableProcessors();
+
+  /**
+   * The default number of threads in the worker pool = 20
+   */
+  public static final int DEFAULT_WORKER_POOL_SIZE = 20;
+
+  /**
+   * The default number of threads in the internal blocking  pool (used by some internal operations) = 20
+   */
+  public static final int DEFAULT_INTERNAL_BLOCKING_POOL_SIZE = 20;
+
+  /**
+   * The default value of blocked thread check interval = 1000 ms.
+   */
+  public static final long DEFAULT_BLOCKED_THREAD_CHECK_INTERVAL = TimeUnit.SECONDS.toMillis(1);
+
+  /**
+   * The default value of blocked thread check interval unit = {@link TimeUnit#MILLISECONDS}
+   */
+  public static final TimeUnit DEFAULT_BLOCKED_THREAD_CHECK_INTERVAL_UNIT = TimeUnit.MILLISECONDS;
+
+  /**
+   * The default value of max event loop execute time = 2000000000 ns (2 seconds)
+   */
+  public static final long DEFAULT_MAX_EVENT_LOOP_EXECUTE_TIME = TimeUnit.SECONDS.toNanos(2);
+
+  /**
+   * The default value of max event loop execute time unit = {@link TimeUnit#NANOSECONDS}
+   */
+  public static final TimeUnit DEFAULT_MAX_EVENT_LOOP_EXECUTE_TIME_UNIT = TimeUnit.NANOSECONDS;
+
+  /**
+   * The default value of max worker execute time = 60000000000 ns (60 seconds)
+   */
+  public static final long DEFAULT_MAX_WORKER_EXECUTE_TIME = TimeUnit.SECONDS.toNanos(60);
+
+  /**
+   * The default value of max worker execute time unit = {@link TimeUnit#NANOSECONDS}
+   */
+  public static final TimeUnit DEFAULT_MAX_WORKER_EXECUTE_TIME_UNIT = TimeUnit.NANOSECONDS;
+
+  /**
+   * The default value of warning exception time 5000000000 ns (5 seconds)
+   * If a thread is blocked longer than this threshold, the warning log
+   * contains a stack trace
+   */
+  private static final long DEFAULT_WARNING_EXCEPTION_TIME = TimeUnit.SECONDS.toNanos(5);
+
+  /**
+   * The default value of warning exception time unit = {@link TimeUnit#NANOSECONDS}
+   */
+  public static final TimeUnit DEFAULT_WARNING_EXCEPTION_TIME_UNIT = TimeUnit.NANOSECONDS;
+
+  public static final boolean DEFAULT_DISABLE_TCCL = Boolean.getBoolean(DISABLE_TCCL_PROP_NAME);
+
+  /**
+   * Set default value to false for aligning with the old behavior
+   * By default, threads are NOT daemons - we want them to prevent JVM exit so embedded user
+   * doesn't have to explicitly prevent JVM from exiting.
+   */
+  public static final boolean DEFAULT_USE_DAEMON_THREAD = false;
+
+  private int eventLoopPoolSize = DEFAULT_EVENT_LOOP_POOL_SIZE;
+  private int workerPoolSize = DEFAULT_WORKER_POOL_SIZE;
+  private int internalBlockingPoolSize = DEFAULT_INTERNAL_BLOCKING_POOL_SIZE;
+  private long blockedThreadCheckInterval = DEFAULT_BLOCKED_THREAD_CHECK_INTERVAL;
+  private long maxEventLoopExecuteTime = DEFAULT_MAX_EVENT_LOOP_EXECUTE_TIME;
+  private long maxWorkerExecuteTime = DEFAULT_MAX_WORKER_EXECUTE_TIME;
+  private long warningExceptionTime = DEFAULT_WARNING_EXCEPTION_TIME;
+  private TimeUnit maxEventLoopExecuteTimeUnit = DEFAULT_MAX_EVENT_LOOP_EXECUTE_TIME_UNIT;
+  private TimeUnit maxWorkerExecuteTimeUnit = DEFAULT_MAX_WORKER_EXECUTE_TIME_UNIT;
+  private TimeUnit warningExceptionTimeUnit = DEFAULT_WARNING_EXCEPTION_TIME_UNIT;
+  private TimeUnit blockedThreadCheckIntervalUnit = DEFAULT_BLOCKED_THREAD_CHECK_INTERVAL_UNIT;
+  private boolean disableTCCL = DEFAULT_DISABLE_TCCL;
+  private Boolean useDaemonThread = DEFAULT_USE_DAEMON_THREAD;
+
+  /**
+   * Default constructor
+   */
+  public AsyncOptions() {
+  }
+
+  /**
+   * Copy constructor
+   *
+   * @param other The other {@code AsyncOptions} to copy when creating this
+   */
+  public AsyncOptions(AsyncOptions other) {
+    this.eventLoopPoolSize = other.getEventLoopPoolSize();
+    this.workerPoolSize = other.getWorkerPoolSize();
+    this.blockedThreadCheckInterval = other.getBlockedThreadCheckInterval();
+    this.maxEventLoopExecuteTime = other.getMaxEventLoopExecuteTime();
+    this.maxWorkerExecuteTime = other.getMaxWorkerExecuteTime();
+    this.internalBlockingPoolSize = other.getInternalBlockingPoolSize();
+    this.warningExceptionTime = other.warningExceptionTime;
+    this.maxEventLoopExecuteTimeUnit = other.maxEventLoopExecuteTimeUnit;
+    this.maxWorkerExecuteTimeUnit = other.maxWorkerExecuteTimeUnit;
+    this.warningExceptionTimeUnit = other.warningExceptionTimeUnit;
+    this.blockedThreadCheckIntervalUnit = other.blockedThreadCheckIntervalUnit;
+    this.disableTCCL = other.disableTCCL;
+    this.useDaemonThread = other.useDaemonThread;
+  }
+
+  /**
+   * Get the number of event loop threads to be used by the instance.
+   *
+   * @return the number of threads
+   */
+  public int getEventLoopPoolSize() {
+    return eventLoopPoolSize;
+  }
+
+  /**
+   * Set the number of event loop threads to be used by the instance.
+   *
+   * @param eventLoopPoolSize the number of threads
+   * @return a reference to this, so the API can be used fluently
+   */
+  public AsyncOptions setEventLoopPoolSize(int eventLoopPoolSize) {
+    if (eventLoopPoolSize < 1) {
+      throw new IllegalArgumentException("eventLoopPoolSize must be > 0");
+    }
+    this.eventLoopPoolSize = eventLoopPoolSize;
+    return this;
+  }
+
+  /**
+   * Get the maximum number of worker threads to be used by the instance.
+   * <p>
+   * Worker threads are used for running blocking code.
+   *
+   * @return the maximum number of worker threads
+   */
+  public int getWorkerPoolSize() {
+    return workerPoolSize;
+  }
+
+  /**
+   * Set the maximum number of worker threads to be used by the instance.
+   *
+   * @param workerPoolSize the number of threads
+   * @return a reference to this, so the API can be used fluently
+   */
+  public AsyncOptions setWorkerPoolSize(int workerPoolSize) {
+    if (workerPoolSize < 1) {
+      throw new IllegalArgumentException("workerPoolSize must be > 0");
+    }
+    this.workerPoolSize = workerPoolSize;
+    return this;
+  }
+
+  /**
+   * Get the value of blocked thread check period, in {@link AsyncOptions#setBlockedThreadCheckIntervalUnit blockedThreadCheckIntervalUnit}.
+   * <p>
+   * This setting determines how often we will check whether event loop threads are executing for too long.
+   * <p>
+   * The default value of {@link AsyncOptions#setBlockedThreadCheckIntervalUnit blockedThreadCheckIntervalUnit} is {@link TimeUnit#MILLISECONDS}.
+   *
+   * @return the value of blocked thread check period, in {@link AsyncOptions#setBlockedThreadCheckIntervalUnit blockedThreadCheckIntervalUnit}.
+   */
+  public long getBlockedThreadCheckInterval() {
+    return blockedThreadCheckInterval;
+  }
+
+  /**
+   * Sets the value of blocked thread check period, in {@link AsyncOptions#setBlockedThreadCheckIntervalUnit blockedThreadCheckIntervalUnit}.
+   * <p>
+   * The default value of {@link AsyncOptions#setBlockedThreadCheckIntervalUnit blockedThreadCheckIntervalUnit} is {@link TimeUnit#MILLISECONDS}
+   *
+   * @param blockedThreadCheckInterval the value of blocked thread check period, in {@link AsyncOptions#setBlockedThreadCheckIntervalUnit blockedThreadCheckIntervalUnit}.
+   * @return a reference to this, so the API can be used fluently
+   */
+  public AsyncOptions setBlockedThreadCheckInterval(long blockedThreadCheckInterval) {
+    if (blockedThreadCheckInterval < 1) {
+      throw new IllegalArgumentException("blockedThreadCheckInterval must be > 0");
+    }
+    this.blockedThreadCheckInterval = blockedThreadCheckInterval;
+    return this;
+  }
+
+  /**
+   * Get the value of max event loop execute time, in {@link AsyncOptions#setMaxEventLoopExecuteTimeUnit maxEventLoopExecuteTimeUnit}.
+   * <p>
+   * We will automatically log a warning if it detects that event loop threads haven't returned within this time.
+   * <p>
+   * This can be used to detect where the user is blocking an event loop thread, contrary to the Golden Rule of the
+   * holy Event Loop.
+   * <p>
+   * The default value of {@link AsyncOptions#setMaxEventLoopExecuteTimeUnit maxEventLoopExecuteTimeUnit} is {@link TimeUnit#NANOSECONDS}
+   *
+   * @return the value of max event loop execute time, in {@link AsyncOptions#setMaxEventLoopExecuteTimeUnit maxEventLoopExecuteTimeUnit}.
+   */
+  public long getMaxEventLoopExecuteTime() {
+    return maxEventLoopExecuteTime;
+  }
+
+  /**
+   * Sets the value of max event loop execute time, in {@link AsyncOptions#setMaxEventLoopExecuteTimeUnit maxEventLoopExecuteTimeUnit}.
+   * <p>
+   * The default value of {@link AsyncOptions#setMaxEventLoopExecuteTimeUnit maxEventLoopExecuteTimeUnit}is {@link TimeUnit#NANOSECONDS}
+   *
+   * @param maxEventLoopExecuteTime the value of max event loop execute time, in {@link AsyncOptions#setMaxEventLoopExecuteTimeUnit maxEventLoopExecuteTimeUnit}.
+   * @return a reference to this, so the API can be used fluently
+   */
+  public AsyncOptions setMaxEventLoopExecuteTime(long maxEventLoopExecuteTime) {
+    if (maxEventLoopExecuteTime < 1) {
+      throw new IllegalArgumentException("maxEventLoopExecuteTime must be > 0");
+    }
+    this.maxEventLoopExecuteTime = maxEventLoopExecuteTime;
+    return this;
+  }
+
+  /**
+   * Get the value of max worker execute time, in {@link AsyncOptions#setMaxWorkerExecuteTimeUnit maxWorkerExecuteTimeUnit}.
+   * <p>
+   * We will automatically log a warning if it detects that worker threads haven't returned within this time.
+   * <p>
+   * This can be used to detect where the user is blocking a worker thread for too long. Although worker threads
+   * can be blocked longer than event loop threads, they shouldn't be blocked for long periods of time.
+   * <p>
+   * The default value of {@link AsyncOptions#setMaxWorkerExecuteTimeUnit maxWorkerExecuteTimeUnit} is {@link TimeUnit#NANOSECONDS}
+   *
+   * @return The value of max worker execute time, in {@link AsyncOptions#setMaxWorkerExecuteTimeUnit maxWorkerExecuteTimeUnit}.
+   */
+  public long getMaxWorkerExecuteTime() {
+    return maxWorkerExecuteTime;
+  }
+
+  /**
+   * Sets the value of max worker execute time, in {@link AsyncOptions#setMaxWorkerExecuteTimeUnit maxWorkerExecuteTimeUnit}.
+   * <p>
+   * The default value of {@link AsyncOptions#setMaxWorkerExecuteTimeUnit maxWorkerExecuteTimeUnit} is {@link TimeUnit#NANOSECONDS}
+   *
+   * @param maxWorkerExecuteTime the value of max worker execute time, in {@link AsyncOptions#setMaxWorkerExecuteTimeUnit maxWorkerExecuteTimeUnit}.
+   * @return a reference to this, so the API can be used fluently
+   */
+  public AsyncOptions setMaxWorkerExecuteTime(long maxWorkerExecuteTime) {
+    if (maxWorkerExecuteTime < 1) {
+      throw new IllegalArgumentException("maxWorkerpExecuteTime must be > 0");
+    }
+    this.maxWorkerExecuteTime = maxWorkerExecuteTime;
+    return this;
+  }
+
+  /**
+   * Get the value of internal blocking pool size.
+   * <p>
+   * We maintain a pool for internal blocking operations.
+   *
+   * @return the value of internal blocking pool size
+   */
+  public int getInternalBlockingPoolSize() {
+    return internalBlockingPoolSize;
+  }
+
+  /**
+   * Set the value of internal blocking pool size
+   *
+   * @param internalBlockingPoolSize the maximumn number of threads in the internal blocking pool
+   * @return a reference to this, so the API can be used fluently
+   */
+  public AsyncOptions setInternalBlockingPoolSize(int internalBlockingPoolSize) {
+    if (internalBlockingPoolSize < 1) {
+      throw new IllegalArgumentException("internalBlockingPoolSize must be > 0");
+    }
+    this.internalBlockingPoolSize = internalBlockingPoolSize;
+    return this;
+  }
+
+  /**
+   * Get the threshold value above this, the blocked warning contains a stack trace. in {@link AsyncOptions#setWarningExceptionTimeUnit warningExceptionTimeUnit}.
+   * <p>
+   * The default value of {@link AsyncOptions#setWarningExceptionTimeUnit warningExceptionTimeUnit} is {@link TimeUnit#NANOSECONDS}
+   *
+   * @return the warning exception time threshold
+   */
+  public long getWarningExceptionTime() {
+    return warningExceptionTime;
+  }
+
+  /**
+   * Set the threshold value above this, the blocked warning contains a stack trace. in {@link AsyncOptions#setWarningExceptionTimeUnit warningExceptionTimeUnit}.
+   * The default value of {@link AsyncOptions#setWarningExceptionTimeUnit warningExceptionTimeUnit} is {@link TimeUnit#NANOSECONDS}
+   *
+   * @param warningExceptionTime
+   * @return a reference to this, so the API can be used fluently
+   */
+  public AsyncOptions setWarningExceptionTime(long warningExceptionTime) {
+    if (warningExceptionTime < 1) {
+      throw new IllegalArgumentException("warningExceptionTime must be > 0");
+    }
+    this.warningExceptionTime = warningExceptionTime;
+    return this;
+  }
+
+  /**
+   * @return the time unit of {@code maxEventLoopExecuteTime}
+   */
+  public TimeUnit getMaxEventLoopExecuteTimeUnit() {
+    return maxEventLoopExecuteTimeUnit;
+  }
+
+  /**
+   * Set the time unit of {@code maxEventLoopExecuteTime}.
+   *
+   * @param maxEventLoopExecuteTimeUnit the time unit of {@code maxEventLoopExecuteTime}
+   * @return a reference to this, so the API can be used fluently
+   */
+  public AsyncOptions setMaxEventLoopExecuteTimeUnit(TimeUnit maxEventLoopExecuteTimeUnit) {
+    this.maxEventLoopExecuteTimeUnit = maxEventLoopExecuteTimeUnit;
+    return this;
+  }
+
+  /**
+   * @return the time unit of {@code maxWorkerExecuteTime}
+   */
+  public TimeUnit getMaxWorkerExecuteTimeUnit() {
+    return maxWorkerExecuteTimeUnit;
+  }
+
+  /**
+   * Set the time unit of {@code maxWorkerExecuteTime}.
+   *
+   * @param maxWorkerExecuteTimeUnit the time unit of {@code maxWorkerExecuteTime}
+   * @return a reference to this, so the API can be used fluently
+   */
+  public AsyncOptions setMaxWorkerExecuteTimeUnit(TimeUnit maxWorkerExecuteTimeUnit) {
+    this.maxWorkerExecuteTimeUnit = maxWorkerExecuteTimeUnit;
+    return this;
+  }
+
+  /**
+   * @return the time unit of {@code warningExceptionTime}
+   */
+  public TimeUnit getWarningExceptionTimeUnit() {
+    return warningExceptionTimeUnit;
+  }
+
+  /**
+   * Set the time unit of {@code warningExceptionTime}.
+   *
+   * @param warningExceptionTimeUnit the time unit of {@code warningExceptionTime}
+   * @return a reference to this, so the API can be used fluently
+   */
+  public AsyncOptions setWarningExceptionTimeUnit(TimeUnit warningExceptionTimeUnit) {
+    this.warningExceptionTimeUnit = warningExceptionTimeUnit;
+    return this;
+  }
+
+  /**
+   * @return the time unit of {@code blockedThreadCheckInterval}
+   */
+  public TimeUnit getBlockedThreadCheckIntervalUnit() {
+    return blockedThreadCheckIntervalUnit;
+  }
+
+  /**
+   * Set the time unit of {@code blockedThreadCheckInterval}.
+   *
+   * @param blockedThreadCheckIntervalUnit the time unit of {@code warningExceptionTime}
+   * @return a reference to this, so the API can be used fluently
+   */
+  public AsyncOptions setBlockedThreadCheckIntervalUnit(TimeUnit blockedThreadCheckIntervalUnit) {
+    this.blockedThreadCheckIntervalUnit = blockedThreadCheckIntervalUnit;
+    return this;
+  }
+
+  /**
+   * @return whether we set the {@link Context} classloader as the thread context classloader on actions executed on that {@link Context}
+   */
+  public boolean getDisableTCCL() {
+    return disableTCCL;
+  }
+
+  /**
+   * Configures whether we set the {@link Context} classloader as the thread context classloader on actions executed on that {@link Context}.
+   *
+   * When a {@link Context} is created the current thread classloader is captured and associated with this classloader.
+   *
+   * This setting overrides the (legacy) system property {@code org.xbib.disableTCCL} and provides control at the
+   * Async instance level.
+   *
+   * @param disableTCCL {@code true} to disable thread context classloader update by Async
+   * @return a reference to this, so the API can be used fluently
+   */
+  public AsyncOptions setDisableTCCL(boolean disableTCCL) {
+    this.disableTCCL = disableTCCL;
+    return this;
+  }
+
+  /**
+   * Returns whether we want to use daemon thread.
+   *
+   * @return {@code true} means daemon, {@code false} means not daemon(user), {@code null} means do
+   *         not change the daemon option of the created thread.
+   */
+  public Boolean getUseDaemonThread() {
+    return useDaemonThread;
+  }
+
+  /**
+   * Mark the thread as daemon thread or user thread.
+   * <p/>
+   * For keeping the old behavior, the default value is {@code false} instead of {@code null}.
+   *
+   * @param daemon {@code true} means daemon, {@code false} means not daemon(user), {@code null}
+   *        means do not change the daemon option of the created thread.
+   */
+  public AsyncOptions setUseDaemonThread(Boolean daemon) {
+    this.useDaemonThread = daemon;
+    return this;
+  }
+
+  @Override
+  public String toString() {
+    return "AsyncOptions{" +
+        "eventLoopPoolSize=" + eventLoopPoolSize +
+        ", workerPoolSize=" + workerPoolSize +
+        ", internalBlockingPoolSize=" + internalBlockingPoolSize +
+        ", blockedThreadCheckIntervalUnit=" + blockedThreadCheckIntervalUnit +
+        ", blockedThreadCheckInterval=" + blockedThreadCheckInterval +
+        ", maxEventLoopExecuteTimeUnit=" + maxEventLoopExecuteTimeUnit +
+        ", maxEventLoopExecuteTime=" + maxEventLoopExecuteTime +
+        ", maxWorkerExecuteTimeUnit=" + maxWorkerExecuteTimeUnit +
+        ", maxWorkerExecuteTime=" + maxWorkerExecuteTime +
+        ", warningExceptionTimeUnit=" + warningExceptionTimeUnit +
+        ", warningExceptionTime=" + warningExceptionTime +
+        ", disableTCCL=" + disableTCCL +
+        ", useDaemonThread=" + useDaemonThread +
+        '}';
+  }
+}

src/main/java/org/xbib/event/async/AsyncResult.java

@@ -0,0 +1,188 @@
+package org.xbib.event.async;
+
+import java.util.function.Function;
+
+/**
+ * Encapsulates the result of an asynchronous operation.
+ * <p>
+ * Many operations in Vert.x APIs provide results back by passing an instance of this in a {@link Handler}.
+ * <p>
+ * The result can either have failed or succeeded.
+ * <p>
+ * If it failed then the cause of the failure is available with {@link #cause}.
+ * <p>
+ * If it succeeded then the actual result is available with {@link #result}
+ *
+ */
+public interface AsyncResult<T> {
+
+  /**
+   * The result of the operation. This will be null if the operation failed.
+   *
+   * @return the result or null if the operation failed.
+   */
+  T result();
+
+  /**
+   * A Throwable describing failure. This will be null if the operation succeeded.
+   *
+   * @return the cause or null if the operation succeeded.
+   */
+  Throwable cause();
+
+  /**
+   * Did it succeed?
+   *
+   * @return true if it succeded or false otherwise
+   */
+  boolean succeeded();
+
+  /**
+   * Did it fail?
+   *
+   * @return true if it failed or false otherwise
+   */
+  boolean failed();
+
+  /**
+   * Apply a {@code mapper} function on this async result.<p>
+   *
+   * The {@code mapper} is called with the completed value and this mapper returns a value. This value will complete the result returned by this method call.<p>
+   *
+   * When this async result is failed, the failure will be propagated to the returned async result and the {@code mapper} will not be called.
+   *
+   * @param mapper the mapper function
+   * @return the mapped async result
+   */
+  default <U> AsyncResult<U> map(Function<T, U> mapper) {
+    if (mapper == null) {
+      throw new NullPointerException();
+    }
+    return new AsyncResult<U>() {
+      @Override
+      public U result() {
+        if (succeeded()) {
+          return mapper.apply(AsyncResult.this.result());
+        } else {
+          return null;
+        }
+      }
+
+      @Override
+      public Throwable cause() {
+        return AsyncResult.this.cause();
+      }
+
+      @Override
+      public boolean succeeded() {
+        return AsyncResult.this.succeeded();
+      }
+
+      @Override
+      public boolean failed() {
+        return AsyncResult.this.failed();
+      }
+    };
+  }
+
+  /**
+   * Map the result of this async result to a specific {@code value}.<p>
+   *
+   * When this async result succeeds, this {@code value} will succeeed the async result returned by this method call.<p>
+   *
+   * When this async result fails, the failure will be propagated to the returned async result.
+   *
+   * @param value the value that eventually completes the mapped async result
+   * @return the mapped async result
+   */
+  default <V> AsyncResult<V> map(V value) {
+    return map(t -> value);
+  }
+
+  /**
+   * Map the result of this async result to {@code null}.<p>
+   *
+   * This is a convenience for {@code asyncResult.map((T) null)} or {@code asyncResult.map((Void) null)}.<p>
+   *
+   * When this async result succeeds, {@code null} will succeeed the async result returned by this method call.<p>
+   *
+   * When this async result fails, the failure will be propagated to the returned async result.
+   *
+   * @return the mapped async result
+   */
+  default <V> AsyncResult<V> mapEmpty() {
+    return map((V)null);
+  }
+
+  /**
+   * Apply a {@code mapper} function on this async result.<p>
+   *
+   * The {@code mapper} is called with the failure and this mapper returns a value. This value will complete the result returned by this method call.<p>
+   *
+   * When this async result is succeeded, the value will be propagated to the returned async result and the {@code mapper} will not be called.
+   *
+   * @param mapper the mapper function
+   * @return the mapped async result
+   */
+  default AsyncResult<T> otherwise(Function<Throwable, T> mapper) {
+    if (mapper == null) {
+      throw new NullPointerException();
+    }
+    return new AsyncResult<T>() {
+      @Override
+      public T result() {
+        if (AsyncResult.this.succeeded()) {
+          return AsyncResult.this.result();
+        } else if (AsyncResult.this.failed()) {
+          return mapper.apply(AsyncResult.this.cause());
+        } else {
+          return null;
+        }
+      }
+
+      @Override
+      public Throwable cause() {
+        return null;
+      }
+
+      @Override
+      public boolean succeeded() {
+        return AsyncResult.this.succeeded() || AsyncResult.this.failed();
+      }
+
+      @Override
+      public boolean failed() {
+        return false;
+      }
+    };
+  }
+
+  /**
+   * Map the failure of this async result to a specific {@code value}.<p>
+   *
+   * When this async result fails, this {@code value} will succeeed the async result returned by this method call.<p>
+   *
+   * When this async succeeds, the result will be propagated to the returned async result.
+   *
+   * @param value the value that eventually completes the mapped async result
+   * @return the mapped async result
+   */
+  default AsyncResult<T> otherwise(T value) {
+    return otherwise(err -> value);
+  }
+
+  /**
+   * Map the failure of this async result to {@code null}.<p>
+   *
+   * This is a convenience for {@code asyncResult.otherwise((T) null)}.<p>
+   *
+   * When this async result fails, the {@code null} will succeeed the async result returned by this method call.<p>
+   *
+   * When this async succeeds, the result will be propagated to the returned async result.
+   *
+   * @return the mapped async result
+   */
+  default AsyncResult<T> otherwiseEmpty() {
+    return otherwise(err -> null);
+  }
+}

src/main/java/org/xbib/event/async/Closeable.java

@@ -0,0 +1,16 @@
+package org.xbib.event.async;
+
+/**
+ * A closeable resource.
+ * <p/>
+ * This interface is mostly used for internal resource management.
+ */
+public interface Closeable {
+
+  /**
+   * Close this resource, the {@code completion} promise must be notified when the operation has completed.
+   *
+   * @param completion the promise to signal when close has completed
+   */
+  void close(Promise<Void> completion);
+}

src/main/java/org/xbib/event/async/CompositeFuture.java

@@ -0,0 +1,245 @@
+package org.xbib.event.async;
+
+import org.xbib.event.async.impl.future.CompositeFutureImpl;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * The composite future wraps a list of {@link Future futures}, it is useful when several futures
+ * needs to be coordinated.
+ * The handlers set for the coordinated futures are overridden by the handler of the composite future.
+ *
+ */
+public interface CompositeFuture extends Future<CompositeFuture> {
+
+  /**
+   * Return a composite future, succeeded when all futures are succeeded, failed when any future is failed.
+   * <p/>
+   * The returned future fails as soon as one of {@code f1} or {@code f2} fails.
+   *
+   * @param f1 future
+   * @param f2 future
+   * @return the composite future
+   */
+  static <T1, T2> CompositeFuture all(Future<T1> f1, Future<T2> f2) {
+    return CompositeFutureImpl.all(f1, f2);
+  }
+
+  /**
+   * Like {@link #all(Future, Future)} but with 3 futures.
+   */
+  static <T1, T2, T3> CompositeFuture all(Future<T1> f1, Future<T2> f2, Future<T3> f3) {
+    return CompositeFutureImpl.all(f1, f2, f3);
+  }
+
+  /**
+   * Like {@link #all(Future, Future)} but with 4 futures.
+   */
+  static <T1, T2, T3, T4> CompositeFuture all(Future<T1> f1, Future<T2> f2, Future<T3> f3, Future<T4> f4) {
+    return CompositeFutureImpl.all(f1, f2, f3, f4);
+  }
+
+  /**
+   * Like {@link #all(Future, Future)} but with 5 futures.
+   */
+  static <T1, T2, T3, T4, T5> CompositeFuture all(Future<T1> f1, Future<T2> f2, Future<T3> f3, Future<T4> f4, Future<T5> f5) {
+    return CompositeFutureImpl.all(f1, f2, f3, f4, f5);
+  }
+
+  /**
+   * Like {@link #all(Future, Future)} but with 6 futures.
+   */
+  static <T1, T2, T3, T4, T5, T6> CompositeFuture all(Future<T1> f1, Future<T2> f2, Future<T3> f3, Future<T4> f4, Future<T5> f5, Future<T6> f6) {
+    return CompositeFutureImpl.all(f1, f2, f3, f4, f5, f6);
+  }
+
+  /**
+   * Like {@link #all(Future, Future)} but with a list of futures.<p>
+   *
+   * When the list is empty, the returned future will be already completed.
+   */
+  static CompositeFuture all(List<Future> futures) {
+    return CompositeFutureImpl.all(futures.toArray(new Future[0]));
+  }
+
+  /**
+   * Return a composite future, succeeded when any futures is succeeded, failed when all futures are failed.
+   * <p/>
+   * The returned future succeeds as soon as one of {@code f1} or {@code f2} succeeds.
+   *
+   * @param f1 future
+   * @param f2 future
+   * @return the composite future
+   */
+  static <T1, T2> CompositeFuture any(Future<T1> f1, Future<T2> f2) {
+    return CompositeFutureImpl.any(f1, f2);
+  }
+
+  /**
+   * Like {@link #any(Future, Future)} but with 3 futures.
+   */
+  static <T1, T2, T3> CompositeFuture any(Future<T1> f1, Future<T2> f2, Future<T3> f3) {
+    return CompositeFutureImpl.any(f1, f2, f3);
+  }
+
+  /**
+   * Like {@link #any(Future, Future)} but with 4 futures.
+   */
+  static <T1, T2, T3, T4> CompositeFuture any(Future<T1> f1, Future<T2> f2, Future<T3> f3, Future<T4> f4) {
+    return CompositeFutureImpl.any(f1, f2, f3, f4);
+  }
+
+  /**
+   * Like {@link #any(Future, Future)} but with 5 futures.
+   */
+  static <T1, T2, T3, T4, T5> CompositeFuture any(Future<T1> f1, Future<T2> f2, Future<T3> f3, Future<T4> f4, Future<T5> f5) {
+    return CompositeFutureImpl.any(f1, f2, f3, f4, f5);
+  }
+
+  /**
+   * Like {@link #any(Future, Future)} but with 6 futures.
+   */
+  static <T1, T2, T3, T4, T5, T6> CompositeFuture any(Future<T1> f1, Future<T2> f2, Future<T3> f3, Future<T4> f4, Future<T5> f5, Future<T6> f6) {
+    return CompositeFutureImpl.any(f1, f2, f3, f4, f5, f6);
+  }
+
+  /**
+   * Like {@link #any(Future, Future)} but with a list of futures.<p>
+   *
+   * When the list is empty, the returned future will be already completed.
+   */
+  static CompositeFuture any(List<Future> futures) {
+    return CompositeFutureImpl.any(futures.toArray(new Future[0]));
+  }
+
+  /**
+   * Return a composite future, succeeded when all futures are succeeded, failed when any future is failed.
+   * <p/>
+   * It always wait until all its futures are completed and will not fail as soon as one of {@code f1} or {@code f2} fails.
+   *
+   * @param f1 future
+   * @param f2 future
+   * @return the composite future
+   */
+  static <T1, T2> CompositeFuture join(Future<T1> f1, Future<T2> f2) {
+    return CompositeFutureImpl.join(f1, f2);
+  }
+
+  /**
+   * Like {@link #join(Future, Future)} but with 3 futures.
+   */
+  static <T1, T2, T3> CompositeFuture join(Future<T1> f1, Future<T2> f2, Future<T3> f3) {
+    return CompositeFutureImpl.join(f1, f2, f3);
+  }
+
+  /**
+   * Like {@link #join(Future, Future)} but with 4 futures.
+   */
+  static <T1, T2, T3, T4> CompositeFuture join(Future<T1> f1, Future<T2> f2, Future<T3> f3, Future<T4> f4) {
+    return CompositeFutureImpl.join(f1, f2, f3, f4);
+  }
+
+  /**
+   * Like {@link #join(Future, Future)} but with 5 futures.
+   */
+  static <T1, T2, T3, T4, T5> CompositeFuture join(Future<T1> f1, Future<T2> f2, Future<T3> f3, Future<T4> f4, Future<T5> f5) {
+    return CompositeFutureImpl.join(f1, f2, f3, f4, f5);
+  }
+
+  /**
+   * Like {@link #join(Future, Future)} but with 6 futures.
+   */
+  static <T1, T2, T3, T4, T5, T6> CompositeFuture join(Future<T1> f1, Future<T2> f2, Future<T3> f3, Future<T4> f4, Future<T5> f5, Future<T6> f6) {
+    return CompositeFutureImpl.join(f1, f2, f3, f4, f5, f6);
+  }
+
+  /**
+   * Like {@link #join(Future, Future)} but with a list of futures.<p>
+   *
+   * When the list is empty, the returned future will be already completed.
+   */
+  static CompositeFuture join(List<Future> futures) {
+    return CompositeFutureImpl.join(futures.toArray(new Future[0]));
+  }
+
+  @Override
+  CompositeFuture onComplete(Handler<AsyncResult<CompositeFuture>> handler);
+
+  @Override
+  default CompositeFuture onSuccess(Handler<CompositeFuture> handler) {
+    Future.super.onSuccess(handler);
+    return this;
+  }
+
+  @Override
+  default CompositeFuture onFailure(Handler<Throwable> handler) {
+    Future.super.onFailure(handler);
+    return this;
+  }
+
+  /**
+   * Returns a cause of a wrapped future
+   *
+   * @param index the wrapped future index
+   */
+  Throwable cause(int index);
+
+  /**
+   * Returns true if a wrapped future is succeeded
+   *
+   * @param index the wrapped future index
+   */
+  boolean succeeded(int index);
+
+  /**
+   * Returns true if a wrapped future is failed
+   *
+   * @param index the wrapped future index
+   */
+  boolean failed(int index);
+
+  /**
+   * Returns true if a wrapped future is completed
+   *
+   * @param index the wrapped future index
+   */
+  boolean isComplete(int index);
+
+  /**
+   * Returns the result of a wrapped future
+   *
+   * @param index the wrapped future index
+   */
+  <T> T resultAt(int index);
+
+  /**
+   * @return the number of wrapped future
+   */
+  int size();
+
+  /**
+   * @return a list of the current completed values. If one future is not yet resolved or is failed, {@code} null
+   *         will be used
+   */
+  default <T> List<T> list() {
+    int size = size();
+    ArrayList<T> list = new ArrayList<>(size);
+    for (int index = 0;index < size;index++) {
+      list.add(resultAt(index));
+    }
+    return list;
+  }
+
+  /**
+   * @return a list of all the eventual failure causes. If no future failed, returns a list of null values.
+   */
+  default List<Throwable> causes() {
+    int size = size();
+    ArrayList<Throwable> list = new ArrayList<>(size);
+    for (int index = 0; index < size; index++) {
+      list.add(cause(index));
+    }
+    return list;
+  }
+}

src/main/java/org/xbib/event/async/Context.java

@@ -0,0 +1,212 @@
+package org.xbib.event.async;
+
+import org.xbib.event.async.impl.AsyncThread;
+import org.xbib.event.loop.EventLoop;
+
+/**
+ * The execution context of a {@link Handler} execution.
+ * <p>
+ * When we provide an event to a handler, the execution is associated with a {@code Context}.
+ * <p>
+ * Usually a context is an *event-loop context* and is tied to a specific event loop thread. So executions for that
+ * context always occur on that exact same event loop thread.
+ * <p>
+ * In the case of running inline blocking code a worker context will be associated with the execution
+ * which will use a thread from the worker thread pool.
+ * <p>
+ * When a handler is set by a thread associated with a specific context, we will guarantee that when that handler
+ * is executed, that execution will be associated with the same context.
+ * <p>
+ * If a handler is set by a thread not associated with a context. Then a new context will
+ * be created for that handler.
+ * <p>
+ * In other words, a context is propagated.
+ * <p>
+ * This class also allows arbitrary data to be {@link #put} and {@link #get} on the context so it can be shared easily
+ * amongst different handlers.
+ * <p>
+ * This class also provides {@link #runOnContext} which allows an action to be executed asynchronously using the same context.
+ *
+ */
+public interface Context {
+
+  /**
+   * Is the current thread a worker thread?
+   * <p>
+   * NOTE! This is not always the same as calling {@link Context#isWorkerContext}. If you are running blocking code
+   * from an event loop context, then this will return true but {@link Context#isWorkerContext} will return false.
+   *
+   * @return true if current thread is a worker thread, false otherwise
+   */
+  static boolean isOnWorkerThread() {
+    Thread t = Thread.currentThread();
+    return t instanceof AsyncThread && ((AsyncThread) t).isWorker();
+  }
+
+  /**
+   * Is the current thread an event thread?
+   * <p>
+   * NOTE! This is not always the same as calling {@link Context#isEventLoopContext}. If you are running blocking code
+   * from an event loop context, then this will return false but {@link Context#isEventLoopContext} will return true.
+   *
+   * @return true if current thread is an event thread, false otherwise
+   */
+  static boolean isOnEventLoopThread() {
+    Thread t = Thread.currentThread();
+    return t instanceof AsyncThread && !((AsyncThread) t).isWorker();
+  }
+
+  /**
+   * Is the current thread an async thread? That's either a worker thread or an event loop thread
+   *
+   * @return true if current thread is an async thread, false otherwise
+   */
+  static boolean isAsyncThread() {
+    return Thread.currentThread() instanceof AsyncThread;
+  }
+
+  /**
+   * Run the specified action asynchronously on the same context, some time after the current execution has completed.
+   *
+   * @param action  the action to run
+   */
+  void runOnContext(Handler<Void> action);
+
+  /**
+   * Safely execute some blocking code.
+   * <p>
+   * Executes the blocking code in the handler {@code blockingCodeHandler} using a thread from the worker pool.
+   * <p>
+   * When the code is complete the handler {@code resultHandler} will be called with the result on the original context
+   * (e.g. on the original event loop of the caller).
+   * <p>
+   * A {@code Future} instance is passed into {@code blockingCodeHandler}. When the blocking code successfully completes,
+   * the handler should call the {@link Promise#complete} or {@link Promise#complete(Object)} method, or the {@link Promise#fail}
+   * method if it failed.
+   * <p>
+   * The blocking code should block for a reasonable amount of time (i.e no more than a few seconds). Long blocking operations
+   * or polling operations (i.e a thread that spin in a loop polling events in a blocking fashion) are precluded.
+   * <p>
+   * When the blocking operation lasts more than the 10 seconds, a message will be printed on the console by the
+   * blocked thread checker.
+   * <p>
+   * Long blocking operations should use a dedicated thread managed by the application, which can interact with
+   * subscribers using the event-bus or {@link Context#runOnContext(Handler)}
+   *
+   * @param blockingCodeHandler  handler representing the blocking code to run
+   * @param ordered  if true then if executeBlocking is called several times on the same context, the executions
+   *                 for that context will be executed serially, not in parallel. if false then they will be no ordering
+   *                 guarantees
+   * @param <T> the type of the result
+   * @return a future completed when the blocking code is complete
+   */
+  <T> Future<T> executeBlocking(Handler<Promise<T>> blockingCodeHandler, boolean ordered);
+
+  /**
+   * Invoke {@link #executeBlocking(Handler, boolean)} with order = true.
+   * @param blockingCodeHandler  handler representing the blocking code to run
+   * @param <T> the type of the result
+   * @return a future completed when the blocking code is complete
+   */
+  default <T> Future<T> executeBlocking(Handler<Promise<T>> blockingCodeHandler) {
+    return executeBlocking(blockingCodeHandler, true);
+  }
+
+  /**
+   * Is the current context an event loop context?
+   * <p>
+   * NOTE! when running blocking code using {@link Async#executeBlocking(Handler, boolean)},
+   * the context will still an event loop context and this {@link this#isEventLoopContext()}
+   * will return true.
+   *
+   * @return true if  false otherwise
+   */
+  boolean isEventLoopContext();
+
+  /**
+   * Is the current context a worker context?
+   * <p>
+   * NOTE! when running blocking code using {@link Async#executeBlocking(Handler, boolean)},
+   * the context will still an event loop context and this {@link this#isWorkerContext()}
+   * will return false.
+   *
+   * @return true if the current context is a worker context, false otherwise
+   */
+  boolean isWorkerContext();
+
+  /**
+   * Get some data from the context.
+   *
+   * @param key  the key of the data
+   * @param <T>  the type of the data
+   * @return the data
+   */
+  <T> T get(Object key);
+
+  /**
+   * Put some data in the context.
+   * <p>
+   * This can be used to share data between different handlers that share a context
+   *
+   * @param key  the key of the data
+   * @param value  the data
+   */
+  void put(Object key, Object value);
+
+  /**
+   * Remove some data from the context.
+   *
+   * @param key  the key to remove
+   * @return true if removed successfully, false otherwise
+   */
+  boolean remove(Object key);
+
+  /**
+   * Get some local data from the context.
+   *
+   * @param key  the key of the data
+   * @param <T>  the type of the data
+   * @return the data
+   */
+  <T> T getLocal(Object key);
+
+  /**
+   * Put some local data in the context.
+   * <p>
+   * This can be used to share data between different handlers that share a context
+   *
+   * @param key  the key of the data
+   * @param value  the data
+   */
+  void putLocal(Object key, Object value);
+
+  /**
+   * Remove some local data from the context.
+   *
+   * @param key  the key to remove
+   * @return true if removed successfully, false otherwise
+   */
+  boolean removeLocal(Object key);
+
+  /**
+   * @return The Async instance that created the context
+   */
+  Async owner();
+
+  /**
+   * Set an exception handler called when the context runs an action throwing an uncaught throwable.<p/>
+   *
+   * When this handler is called, {@link Async#currentContext()} will return this context.
+   *
+   * @param handler the exception handler
+   * @return a reference to this, so the API can be used fluently
+   */
+  Context exceptionHandler(Handler<Throwable> handler);
+
+  /**
+   * @return the current exception handler of this context
+   */
+  Handler<Throwable> exceptionHandler();
+
+  EventLoop eventLoop();
+}

src/main/java/org/xbib/event/async/EventException.java

@@ -0,0 +1,67 @@
+package org.xbib.event.async;
+
+/**
+ * This is a general purpose exception class that is often thrown if things go wrong.
+ *
+ */
+public class EventException extends RuntimeException {
+
+  /**
+   * Create an instance given a message
+   *
+   * @param message  the message
+   */
+  public EventException(String message) {
+    super(message);
+  }
+
+  /**
+   * Create an instance given a message and a cause
+   *
+   * @param message  the message
+   * @param cause  the cause
+   */
+  public EventException(String message, Throwable cause) {
+    super(message, cause);
+  }
+
+  /**
+   * Create an instance given a cause
+   *
+   * @param cause  the cause
+   */
+  public EventException(Throwable cause) {
+    super(cause);
+  }
+
+  /**
+   * Create an instance given a message
+   *
+   * @param message  the message
+   * @param noStackTrace  disable stack trace capture
+   */
+  public EventException(String message, boolean noStackTrace) {
+    super(message, null, !noStackTrace, !noStackTrace);
+  }
+
+  /**
+   * Create an instance given a message
+   *
+   * @param message  the message
+   * @param cause  the cause
+   * @param noStackTrace  disable stack trace capture
+   */
+  public EventException(String message, Throwable cause, boolean noStackTrace) {
+    super(message, cause, !noStackTrace, !noStackTrace);
+  }
+
+  /**
+   * Create an instance given a message
+   *
+   * @param cause  the cause
+   * @param noStackTrace  disable stack trace capture
+   */
+  public EventException(Throwable cause, boolean noStackTrace) {
+    super(null, cause, !noStackTrace, !noStackTrace);
+  }
+}

src/main/java/org/xbib/event/async/Future.java

@@ -0,0 +1,414 @@
+package org.xbib.event.async;
+
+import org.xbib.event.async.impl.ContextInternal;
+import org.xbib.event.async.impl.future.FailedFuture;
+import org.xbib.event.async.impl.future.SucceededFuture;
+
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionStage;
+import java.util.function.Function;
+
+/**
+ * Represents the result of an action that may, or may not, have occurred yet.
+ */
+public interface Future<T> extends AsyncResult<T> {
+
+  /**
+   * Create a future that hasn't completed yet and that is passed to the {@code handler} before it is returned.
+   *
+   * @param handler the handler
+   * @param <T> the result type
+   * @return the future.
+   */
+  static <T> Future<T> future(Handler<Promise<T>> handler) {
+    Promise<T> promise = Promise.promise();
+    try {
+      handler.handle(promise);
+    } catch (Throwable e){
+      promise.tryFail(e);
+    }
+    return promise.future();
+  }
+
+  /**
+   * Create a succeeded future with a null result
+   *
+   * @param <T>  the result type
+   * @return  the future
+   */
+  static <T> Future<T> succeededFuture() {
+    return (Future<T>) SucceededFuture.EMPTY;
+  }
+
+  /**
+   * Created a succeeded future with the specified result.
+   *
+   * @param result  the result
+   * @param <T>  the result type
+   * @return  the future
+   */
+  static <T> Future<T> succeededFuture(T result) {
+    if (result == null) {
+      return succeededFuture();
+    } else {
+      return new SucceededFuture<>(result);
+    }
+  }
+
+  /**
+   * Create a failed future with the specified failure cause.
+   *
+   * @param t  the failure cause as a Throwable
+   * @param <T>  the result type
+   * @return  the future
+   */
+  static <T> Future<T> failedFuture(Throwable t) {
+    return new FailedFuture<>(t);
+  }
+
+  /**
+   * Create a failed future with the specified failure message.
+   *
+   * @param failureMessage  the failure message
+   * @param <T>  the result type
+   * @return  the future
+   */
+  static <T> Future<T> failedFuture(String failureMessage) {
+    return new FailedFuture<>(failureMessage);
+  }
+
+  /**
+   * Has the future completed?
+   * <p>
+   * It's completed if it's either succeeded or failed.
+   *
+   * @return true if completed, false if not
+   */
+  boolean isComplete();
+
+  /**
+   * Add a handler to be notified of the result.
+   * <p>
+   * <em><strong>WARNING</strong></em>: this is a terminal operation.
+   * If several {@code handler}s are registered, there is no guarantee that they will be invoked in order of registration.
+   *
+   * @param handler the handler that will be called with the result
+   * @return a reference to this, so it can be used fluently
+   */
+  Future<T> onComplete(Handler<AsyncResult<T>> handler);
+
+  /**
+   * Add a handler to be notified of the succeeded result.
+   * <p>
+   * <em><strong>WARNING</strong></em>: this is a terminal operation.
+   * If several {@code handler}s are registered, there is no guarantee that they will be invoked in order of registration.
+   *
+   * @param handler the handler that will be called with the succeeded result
+   * @return a reference to this, so it can be used fluently
+   */
+  default Future<T> onSuccess(Handler<T> handler) {
+    return onComplete(ar -> {
+      if (ar.succeeded()) {
+        handler.handle(ar.result());
+      }
+    });
+  }
+
+  /**
+   * Add a handler to be notified of the failed result.
+   * <p>
+   * <em><strong>WARNING</strong></em>: this is a terminal operation.
+   * If several {@code handler}s are registered, there is no guarantee that they will be invoked in order of registration.
+   *
+   * @param handler the handler that will be called with the failed result
+   * @return a reference to this, so it can be used fluently
+   */
+  default Future<T> onFailure(Handler<Throwable> handler) {
+    return onComplete(ar -> {
+      if (ar.failed()) {
+        handler.handle(ar.cause());
+      }
+    });
+  }
+
+  /**
+   * The result of the operation. This will be null if the operation failed.
+   *
+   * @return the result or null if the operation failed.
+   */
+  @Override
+  T result();
+
+  /**
+   * A Throwable describing failure. This will be null if the operation succeeded.
+   *
+   * @return the cause or null if the operation succeeded.
+   */
+  @Override
+  Throwable cause();
+
+  /**
+   * Did it succeed?
+   *
+   * @return true if it succeded or false otherwise
+   */
+  @Override
+  boolean succeeded();
+
+  /**
+   * Did it fail?
+   *
+   * @return true if it failed or false otherwise
+   */
+  @Override
+  boolean failed();
+
+  /**
+   * Alias for {@link #compose(Function)}.
+   */
+  default <U> Future<U> flatMap(Function<T, Future<U>> mapper) {
+    return compose(mapper);
+  }
+
+  /**
+   * Compose this future with a {@code mapper} function.<p>
+   *
+   * When this future (the one on which {@code compose} is called) succeeds, the {@code mapper} will be called with
+   * the completed value and this mapper returns another future object. This returned future completion will complete
+   * the future returned by this method call.<p>
+   *
+   * If the {@code mapper} throws an exception, the returned future will be failed with this exception.<p>
+   *
+   * When this future fails, the failure will be propagated to the returned future and the {@code mapper}
+   * will not be called.
+   *
+   * @param mapper the mapper function
+   * @return the composed future
+   */
+  default <U> Future<U> compose(Function<T, Future<U>> mapper) {
+    return compose(mapper, Future::failedFuture);
+  }
+
+  /**
+   * Handles a failure of this Future by returning the result of another Future.
+   * If the mapper fails, then the returned future will be failed with this failure.
+   *
+   * @param mapper A function which takes the exception of a failure and returns a new future.
+   * @return A recovered future
+   */
+  default Future<T> recover(Function<Throwable, Future<T>> mapper) {
+    return compose(Future::succeededFuture, mapper);
+  }
+
+  /**
+   * Compose this future with a {@code successMapper} and {@code failureMapper} functions.<p>
+   *
+   * When this future (the one on which {@code compose} is called) succeeds, the {@code successMapper} will be called with
+   * the completed value and this mapper returns another future object. This returned future completion will complete
+   * the future returned by this method call.<p>
+   *
+   * When this future (the one on which {@code compose} is called) fails, the {@code failureMapper} will be called with
+   * the failure and this mapper returns another future object. This returned future completion will complete
+   * the future returned by this method call.<p>
+   *
+   * If any mapper function throws an exception, the returned future will be failed with this exception.<p>
+   *
+   * @param successMapper the function mapping the success
+   * @param failureMapper the function mapping the failure
+   * @return the composed future
+   */
+  <U> Future<U> compose(Function<T, Future<U>> successMapper, Function<Throwable, Future<U>> failureMapper);
+
+  /**
+   * Transform this future with a {@code mapper} functions.<p>
+   *
+   * When this future (the one on which {@code transform} is called) completes, the {@code mapper} will be called with
+   * the async result and this mapper returns another future object. This returned future completion will complete
+   * the future returned by this method call.<p>
+   *
+   * If any mapper function throws an exception, the returned future will be failed with this exception.<p>
+   *
+   * @param mapper the function mapping the future
+   * @return the transformed future
+   */
+  <U> Future<U> transform(Function<AsyncResult<T>, Future<U>> mapper);
+
+  /**
+   * Compose this future with a {@code mapper} that will be always be called.
+   *
+   * <p>When this future (the one on which {@code eventually} is called) completes, the {@code mapper} will be called
+   * and this mapper returns another future object. This returned future completion will complete the future returned
+   * by this method call with the original result of the future.
+   *
+   * <p>The outcome of the future returned by the {@code mapper} will not influence the nature
+   * of the returned future.
+   *
+   * @param mapper the function returning the future.
+   * @return the composed future
+   */
+  <U> Future<T> eventually(Function<Void, Future<U>> mapper);
+
+  /**
+   * Apply a {@code mapper} function on this future.<p>
+   *
+   * When this future succeeds, the {@code mapper} will be called with the completed value and this mapper
+   * returns a value. This value will complete the future returned by this method call.<p>
+   *
+   * If the {@code mapper} throws an exception, the returned future will be failed with this exception.<p>
+   *
+   * When this future fails, the failure will be propagated to the returned future and the {@code mapper}
+   * will not be called.
+   *
+   * @param mapper the mapper function
+   * @return the mapped future
+   */
+  <U> Future<U> map(Function<T, U> mapper);
+
+  /**
+   * Map the result of a future to a specific {@code value}.<p>
+   *
+   * When this future succeeds, this {@code value} will complete the future returned by this method call.<p>
+   *
+   * When this future fails, the failure will be propagated to the returned future.
+   *
+   * @param value the value that eventually completes the mapped future
+   * @return the mapped future
+   */
+  <V> Future<V> map(V value);
+
+  /**
+   * Map the result of a future to {@code null}.<p>
+   *
+   * This is a conveniency for {@code future.map((T) null)} or {@code future.map((Void) null)}.<p>
+   *
+   * When this future succeeds, {@code null} will complete the future returned by this method call.<p>
+   *
+   * When this future fails, the failure will be propagated to the returned future.
+   *
+   * @return the mapped future
+   */
+  @Override
+  default <V> Future<V> mapEmpty() {
+    return (Future<V>) AsyncResult.super.mapEmpty();
+  }
+
+  /**
+   * Apply a {@code mapper} function on this future.<p>
+   *
+   * When this future fails, the {@code mapper} will be called with the completed value and this mapper
+   * returns a value. This value will complete the future returned by this method call.<p>
+   *
+   * If the {@code mapper} throws an exception, the returned future will be failed with this exception.<p>
+   *
+   * When this future succeeds, the result will be propagated to the returned future and the {@code mapper}
+   * will not be called.
+   *
+   * @param mapper the mapper function
+   * @return the mapped future
+   */
+  Future<T> otherwise(Function<Throwable, T> mapper);
+
+  /**
+   * Map the failure of a future to a specific {@code value}.<p>
+   *
+   * When this future fails, this {@code value} will complete the future returned by this method call.<p>
+   *
+   * When this future succeeds, the result will be propagated to the returned future.
+   *
+   * @param value the value that eventually completes the mapped future
+   * @return the mapped future
+   */
+  Future<T> otherwise(T value);
+
+  /**
+   * Map the failure of a future to {@code null}.<p>
+   *
+   * This is a convenience for {@code future.otherwise((T) null)}.<p>
+   *
+   * When this future fails, the {@code null} value will complete the future returned by this method call.<p>
+   *
+   * When this future succeeds, the result will be propagated to the returned future.
+   *
+   * @return the mapped future
+   */
+  default Future<T> otherwiseEmpty() {
+    return (Future<T>) AsyncResult.super.otherwiseEmpty();
+  }
+
+  /**
+   * Invokes the given {@code handler} upon completion.
+   * <p>
+   * If the {@code handler} throws an exception, the returned future will be failed with this exception.
+   *
+   * @param handler invoked upon completion of this future
+   * @return a future completed after the {@code handler} has been invoked
+   */
+  default Future<T> andThen(Handler<AsyncResult<T>> handler) {
+    return transform(ar -> {
+      handler.handle(ar);
+      return (Future<T>) ar;
+    });
+  }
+
+  /**
+   * Bridges this Vert.x future to a {@link CompletionStage} instance.
+   * <p>
+   * The {@link CompletionStage} handling methods will be called from the thread that resolves this future.
+   *
+   * @return a {@link CompletionStage} that completes when this future resolves
+   */
+  default CompletionStage<T> toCompletionStage() {
+    CompletableFuture<T> completableFuture = new CompletableFuture<>();
+    onComplete(ar -> {
+      if (ar.succeeded()) {
+        completableFuture.complete(ar.result());
+      } else {
+        completableFuture.completeExceptionally(ar.cause());
+      }
+    });
+    return completableFuture;
+  }
+
+  /**
+   * Bridges a {@link CompletionStage} object to a Vert.x future instance.
+   * <p>
+   * The Vert.x future handling methods will be called from the thread that completes {@code completionStage}.
+   *
+   * @param completionStage a completion stage
+   * @param <T>             the result type
+   * @return a Vert.x future that resolves when {@code completionStage} resolves
+   */
+  static <T> Future<T> fromCompletionStage(CompletionStage<T> completionStage) {
+    Promise<T> promise = Promise.promise();
+    completionStage.whenComplete((value, err) -> {
+      if (err != null) {
+        promise.fail(err);
+      } else {
+        promise.complete(value);
+      }
+    });
+    return promise.future();
+  }
+
+  /**
+   * Bridges a {@link CompletionStage} object to a Vert.x future instance.
+   * <p>
+   * The Vert.x future handling methods will be called on the provided {@code context}.
+   *
+   * @param completionStage a completion stage
+   * @param context         a Vert.x context to dispatch to
+   * @param <T>             the result type
+   * @return a Vert.x future that resolves when {@code completionStage} resolves
+   */
+  static <T> Future<T> fromCompletionStage(CompletionStage<T> completionStage, Context context) {
+    Promise<T> promise = ((ContextInternal) context).promise();
+    completionStage.whenComplete((value, err) -> {
+      if (err != null) {
+        promise.fail(err);
+      } else {
+        promise.complete(value);
+      }
+    });
+    return promise.future();
+  }
+}

src/main/java/org/xbib/event/async/Handler.java

@@ -0,0 +1,18 @@
+package org.xbib.event.async;
+
+/**
+ *  A generic event handler.
+ *  <p>
+ *  This interface is used heavily throughout Vert.x as a handler for all types of asynchronous occurrences.
+ *  <p>
+ */
+@FunctionalInterface
+public interface Handler<E> {
+
+  /**
+   * Something has happened, so handle it.
+   *
+   * @param event  the event to handle
+   */
+  void handle(E event);
+}

src/main/java/org/xbib/event/async/NoStackTraceThrowable.java

@@ -0,0 +1,8 @@
+package org.xbib.event.async;
+
+public class NoStackTraceThrowable extends Throwable {
+
+  public NoStackTraceThrowable(String message) {
+    super(message, null, false, false);
+  }
+}

src/main/java/org/xbib/event/async/Promise.java

@@ -0,0 +1,130 @@
+package org.xbib.event.async;
+
+import org.xbib.event.async.impl.future.PromiseImpl;
+
+/**
+ * Represents the writable side of an action that may, or may not, have occurred yet.
+ * <p>
+ * The {@link #future()} method returns the {@link Future} associated with a promise, the future
+ * can be used for getting notified of the promise completion and retrieve its value.
+ * <p>
+ * A promise extends {@code Handler<AsyncResult<T>>} so it can be used as a callback.
+ */
+public interface Promise<T> extends Handler<AsyncResult<T>> {
+
+  /**
+   * Create a promise that hasn't completed yet
+   *
+   * @param <T>  the result type
+   * @return  the promise
+   */
+  static <T> Promise<T> promise() {
+    return new PromiseImpl<>();
+  }
+
+  /**
+   * Succeed or fail this promise with the {@link AsyncResult} event.
+   *
+   * @param asyncResult the async result to handle
+   */
+  @Override
+  default void handle(AsyncResult<T> asyncResult) {
+    if (asyncResult.succeeded()) {
+      complete(asyncResult.result());
+    } else {
+      fail(asyncResult.cause());
+    }
+  }
+
+  /**
+   * Set the result. Any handler will be called, if there is one, and the promise will be marked as completed.
+   * <p/>
+   * Any handler set on the associated promise will be called.
+   *
+   * @param result  the result
+   * @throws IllegalStateException when the promise is already completed
+   */
+  default void complete(T result) {
+    if (!tryComplete(result)) {
+      throw new IllegalStateException("Result is already complete");
+    }
+  }
+
+  /**
+   * Calls {@code complete(null)}
+   *
+   * @throws IllegalStateException when the promise is already completed
+   */
+  default void complete() {
+    if (!tryComplete()) {
+      throw new IllegalStateException("Result is already complete");
+    }
+  }
+
+  /**
+   * Set the failure. Any handler will be called, if there is one, and the future will be marked as completed.
+   *
+   * @param cause  the failure cause
+   * @throws IllegalStateException when the promise is already completed
+   */
+  default void fail(Throwable cause) {
+    if (!tryFail(cause)) {
+      throw new IllegalStateException("Result is already complete");
+    }
+  }
+
+  /**
+   * Calls {@link #fail(Throwable)} with the {@code message}.
+   *
+   * @param message  the failure message
+   * @throws IllegalStateException when the promise is already completed
+   */
+  default void fail(String message) {
+    if (!tryFail(message)) {
+      throw new IllegalStateException("Result is already complete");
+    }
+  }
+
+  /**
+   * Like {@link #complete(Object)} but returns {@code false} when the promise is already completed instead of throwing
+   * an {@link IllegalStateException}, it returns {@code true} otherwise.
+   *
+   * @param result  the result
+   * @return {@code false} when the future is already completed
+   */
+  boolean tryComplete(T result);
+
+  /**
+   * Calls {@code tryComplete(null)}.
+   *
+   * @return {@code false} when the future is already completed
+   */
+  default boolean tryComplete() {
+    return tryComplete(null);
+  }
+
+  /**
+   * Like {@link #fail(Throwable)} but returns {@code false} when the promise is already completed instead of throwing
+   * an {@link IllegalStateException}, it returns {@code true} otherwise.
+   *
+   * @param cause  the failure cause
+   * @return {@code false} when the future is already completed
+   */
+  boolean tryFail(Throwable cause);
+
+  /**
+   * Calls {@link #fail(Throwable)} with the {@code message}.
+   *
+   * @param message  the failure message
+   * @return false when the future is already completed
+   */
+  default boolean tryFail(String message) {
+    return tryFail(new NoStackTraceThrowable(message));
+  }
+
+  /**
+   * @return the {@link Future} associated with this promise, it can be used to be aware of the promise completion
+   */
+  Future<T> future();
+
+}

src/main/java/org/xbib/event/async/TimeoutStream.java

@@ -0,0 +1,40 @@
+package org.xbib.event.async;
+
+import org.xbib.event.async.streams.ReadStream;
+
+/**
+ * A timeout stream is triggered by a timer, the {@link Handler} will be call when the timer is fired,
+ * it can be once or several times depending on the nature of the timer related to this stream. The
+ * {@link ReadStream#endHandler(Handler)} will be called after the timer handler has been called.
+ * <p>
+ * Pausing the timer inhibits the timer shots until the stream is resumed. Setting a null handler callback cancels
+ * the timer.
+ *
+ */
+public interface TimeoutStream extends ReadStream<Long> {
+
+  @Override
+  TimeoutStream exceptionHandler(Handler<Throwable> handler);
+
+  @Override
+  TimeoutStream handler(Handler<Long> handler);
+
+  @Override
+  TimeoutStream pause();
+
+  @Override
+  TimeoutStream resume();
+
+  @Override
+  TimeoutStream fetch(long amount);
+
+  @Override
+  TimeoutStream endHandler(Handler<Void> endHandler);
+
+  /**
+   * Cancels the timeout. Note this has the same effect as calling {@link #handler(Handler)} with a null
+   * argument.
+   */
+  void cancel();
+
+}

src/main/java/org/xbib/event/async/WorkerExecutor.java

@@ -0,0 +1,47 @@
+package org.xbib.event.async;
+
+/**
+ * An executor for executing blocking code.<p>
+ *
+ * It provides the same <code>executeBlocking</code> operation than {@link Context} and
+ * {@link Async} but on a separate worker pool.<p>
+ */
+public interface WorkerExecutor {
+
+  /**
+   * Safely execute some blocking code.
+   * <p>
+   * Executes the blocking code in the handler {@code blockingCodeHandler} using a thread from the worker pool.
+   * <p>
+   * When the code is complete the handler {@code resultHandler} will be called with the result on the original context
+   * (i.e. on the original event loop of the caller).
+   * <p>
+   * A {@code Future} instance is passed into {@code blockingCodeHandler}. When the blocking code successfully completes,
+   * the handler should call the {@link Promise#complete} or {@link Promise#complete(Object)} method, or the {@link Promise#fail}
+   * method if it failed.
+   * <p>
+   * In the {@code blockingCodeHandler} the current context remains the original context and therefore any task
+   * scheduled in the {@code blockingCodeHandler} will be executed on the this context and not on the worker thread.
+   *
+   * @param blockingCodeHandler  handler representing the blocking code to run
+   * @param ordered  if true then if executeBlocking is called several times on the same context, the executions
+   *                 for that context will be executed serially, not in parallel. if false then they will be no ordering
+   *                 guarantees
+   * @param <T> the type of the result
+   * @return a future notified with the result
+   */
+  <T> Future<T> executeBlocking(Handler<Promise<T>> blockingCodeHandler, boolean ordered);
+
+  /**
+   * Like {@link #executeBlocking(Handler, boolean)} called with ordered = true.
+   */
+  default <T> Future<T> executeBlocking(Handler<Promise<T>> blockingCodeHandler) {
+    return executeBlocking(blockingCodeHandler, true);
+  }
+
+  /**
+   * Close the executor.
+   */
+  Future<Void> close();
+
+}

src/main/java/org/xbib/event/async/impl/AsyncBuilder.java

@@ -0,0 +1,110 @@
+package org.xbib.event.async.impl;
+
+import org.xbib.event.async.Async;
+import org.xbib.event.async.AsyncOptions;
+import org.xbib.event.async.spi.AsyncThreadFactory;
+import org.xbib.event.async.spi.ExecutorServiceFactory;
+import org.xbib.event.loop.EventLoopGroup;
+
+/**
+ * Async builder for creating instances with SPI overrides.
+ */
+public class AsyncBuilder {
+
+  private final AsyncOptions options;
+  private AsyncThreadFactory threadFactory;
+  private ExecutorServiceFactory executorServiceFactory;
+
+  private EventLoopGroup eventLoopGroup;
+
+  public AsyncBuilder() {
+    this(new AsyncOptions());
+  }
+
+  public AsyncBuilder(AsyncOptions options) {
+    this.options = options;
+  }
+
+  /**
+   * @return the options
+   */
+  public AsyncOptions options() {
+    return options;
+  }
+
+  /**
+   * @return the {@code AsyncThreadFactory} to use
+   */
+  public AsyncThreadFactory threadFactory() {
+    return threadFactory;
+  }
+
+  /**
+   * Set the {@code AsyncThreadFactory} instance to use.
+   * @param factory the metrics
+   * @return this builder instance
+   */
+  public AsyncBuilder threadFactory(AsyncThreadFactory factory) {
+    this.threadFactory = factory;
+    return this;
+  }
+
+  /**
+   * @return the {@code ExecutorServiceFactory} to use
+   */
+  public ExecutorServiceFactory executorServiceFactory() {
+    return executorServiceFactory;
+  }
+
+  /**
+   * Set the {@code ExecutorServiceFactory} instance to use.
+   * @param factory the factory
+   * @return this builder instance
+   */
+  public AsyncBuilder executorServiceFactory(ExecutorServiceFactory factory) {
+    this.executorServiceFactory = factory;
+    return this;
+  }
+
+  public EventLoopGroup eventLoopGroup() {
+    return eventLoopGroup;
+  }
+
+  public AsyncBuilder eventLoopGroup(EventLoopGroup eventLoopGroup) {
+    this.eventLoopGroup = eventLoopGroup;
+    return this;
+  }
+
+  /**
+   * Build and return the instance
+   */
+  public Async newInstance() {
+    AsyncImpl async = new AsyncImpl(options, threadFactory, executorServiceFactory, eventLoopGroup);
+    async.init();
+    return async;
+  }
+
+  /**
+   * Initialize the service providers.
+   * @return this builder instance
+   */
+  public AsyncBuilder init() {
+    initThreadFactory();
+    initExecutorServiceFactory();
+    return this;
+  }
+
+  private void initThreadFactory() {
+    if (threadFactory != null) {
+      return;
+    }
+    threadFactory = AsyncThreadFactory.INSTANCE;
+  }
+
+  private void initExecutorServiceFactory() {
+    if (executorServiceFactory != null) {
+      return;
+    }
+    executorServiceFactory = ExecutorServiceFactory.INSTANCE;
+  }
+}

src/main/java/org/xbib/event/async/impl/AsyncImpl.java

@@ -0,0 +1,558 @@
+package org.xbib.event.async.impl;
+
+import org.xbib.event.async.Async;
+import org.xbib.event.async.AsyncOptions;
+import org.xbib.event.async.Closeable;
+import org.xbib.event.async.Future;
+import org.xbib.event.async.Handler;
+import org.xbib.event.async.Promise;
+import org.xbib.event.async.TimeoutStream;
+import org.xbib.event.async.impl.future.PromiseInternal;
+import org.xbib.event.async.spi.AsyncThreadFactory;
+import org.xbib.event.async.spi.ExecutorServiceFactory;
+import org.xbib.event.loop.EventLoop;
+import org.xbib.event.loop.EventLoopGroup;
+
+import java.lang.ref.WeakReference;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class AsyncImpl implements AsyncInternal {
+
+  /**
+   * Context dispatch info for context running with external threads.
+   */
+  static final ThreadLocal<ContextDispatch> nonContextDispatch = new ThreadLocal<>();
+
+  private static final Logger log = Logger.getLogger(AsyncImpl.class.getName());
+
+  private final ConcurrentMap<Long, InternalTimerHandler> timeouts = new ConcurrentHashMap<>();
+  private final AtomicLong timeoutCounter = new AtomicLong(0);
+  final WorkerPool workerPool;
+  final WorkerPool internalWorkerPool;
+
+  private final EventLoopGroup eventLoopGroup;
+  private boolean closed;
+  private volatile Handler<Throwable> exceptionHandler;
+  private final CloseFuture closeFuture;
+  private final ThreadLocal<WeakReference<ContextInternal>> stickyContext = new ThreadLocal<>();
+  private final boolean disableTCCL;
+
+  AsyncImpl(AsyncOptions options,
+            AsyncThreadFactory threadFactory,
+            ExecutorServiceFactory executorServiceFactory,
+            EventLoopGroup eventLoopGroup) {
+    this.eventLoopGroup = eventLoopGroup;
+    if (Async.currentContext() != null) {
+      log.log(Level.WARNING, "You're already on a context, are you sure you want to create a new instance?");
+    }
+
+    Boolean useDaemonThread = options.getUseDaemonThread();
+    int workerPoolSize = options.getWorkerPoolSize();
+    int internalBlockingPoolSize = options.getInternalBlockingPoolSize();
+    long maxEventLoopExecuteTime = options.getMaxEventLoopExecuteTime();
+    TimeUnit maxEventLoopExecuteTimeUnit = options.getMaxEventLoopExecuteTimeUnit();
+    TimeUnit maxWorkerExecuteTimeUnit = options.getMaxWorkerExecuteTimeUnit();
+    long maxWorkerExecuteTime = options.getMaxWorkerExecuteTime();
+
+    ThreadFactory workerThreadFactory = createThreadFactory(threadFactory, useDaemonThread, maxWorkerExecuteTime, maxWorkerExecuteTimeUnit, "async-worker-thread-", true);
+    ExecutorService workerExec = executorServiceFactory.createExecutor(workerThreadFactory, workerPoolSize, workerPoolSize);
+    ThreadFactory internalWorkerThreadFactory = createThreadFactory(threadFactory, useDaemonThread, maxWorkerExecuteTime, maxWorkerExecuteTimeUnit, "async-internal-blocking-", true);
+    ExecutorService internalWorkerExec = executorServiceFactory.createExecutor(internalWorkerThreadFactory, internalBlockingPoolSize, internalBlockingPoolSize);
+
+    closeFuture = new CloseFuture(log);
+
+    internalWorkerPool = new WorkerPool(internalWorkerExec);
+    workerPool = new WorkerPool(workerExec);
+    int defaultWorkerPoolSize = options.getWorkerPoolSize();
+    disableTCCL = options.getDisableTCCL();
+  }
+
+  void init() {
+  }
+
+  @Override
+  public TimeoutStream periodicStream(long initialDelay, long delay) {
+    return new TimeoutStreamImpl(initialDelay, delay, true);
+  }
+
+  @Override
+  public long setTimer(long delay, Handler<Long> handler) {
+    ContextInternal ctx = getOrCreateContext();
+    return scheduleTimeout(ctx, false, delay, TimeUnit.MILLISECONDS, false, handler);
+  }
+
+  @Override
+  public TimeoutStream timerStream(long delay) {
+    return new TimeoutStreamImpl(delay, false);
+  }
+
+  @Override
+  public long setPeriodic(long initialDelay, long delay, Handler<Long> handler) {
+    ContextInternal ctx = getOrCreateContext();
+    return scheduleTimeout(ctx, true, initialDelay, delay, TimeUnit.MILLISECONDS, false, handler);
+  }
+
+  @Override
+  public <T> PromiseInternal<T> promise() {
+    ContextInternal context = getOrCreateContext();
+    return context.promise();
+  }
+
+  public <T> PromiseInternal<T> promise(Promise<T> p) {
+    if (p instanceof PromiseInternal) {
+      PromiseInternal<T> promise = (PromiseInternal<T>) p;
+      if (promise.context() != null) {
+        return promise;
+      }
+    }
+    PromiseInternal<T> promise = promise();
+    promise.future().onComplete(p);
+    return promise;
+  }
+
+  public void runOnContext(Handler<Void> task) {
+    ContextInternal context = getOrCreateContext();
+    context.runOnContext(task);
+  }
+
+  // The background pool is used for making blocking calls to legacy synchronous APIs
+  public WorkerPool getWorkerPool() {
+    return workerPool;
+  }
+
+  @Override
+  public WorkerPool getInternalWorkerPool() {
+    return internalWorkerPool;
+  }
+
+
+  @Override
+  public ContextInternal getOrCreateContext() {
+    ContextInternal ctx = getContext();
+    if (ctx == null) {
+      ctx = createEventLoopContext();
+      stickyContext.set(new WeakReference<>(ctx));
+    }
+    return ctx;
+  }
+
+  @Override
+  public boolean cancelTimer(long id) {
+    InternalTimerHandler handler = timeouts.get(id);
+    if (handler != null) {
+      return handler.cancel();
+    } else {
+      return false;
+    }
+  }
+
+  private EventLoopContext createEventLoopContext() {
+    return createEventLoopContext(closeFuture, null, Thread.currentThread().getContextClassLoader());
+  }
+
+  private EventLoopContext createEventLoopContext(CloseFuture closeFuture, WorkerPool workerPool, ClassLoader tccl) {
+    return new EventLoopContext(this, eventLoopGroup.next(), internalWorkerPool, workerPool != null ? workerPool : this.workerPool, closeFuture, disableTCCL ? null : tccl);
+  }
+
+  private long scheduleTimeout(ContextInternal context,
+                              boolean periodic,
+                              long initialDelay,
+                              long delay,
+                              TimeUnit timeUnit,
+                              boolean addCloseHook,
+                              Handler<Long> handler) {
+    if (delay < 1) {
+      throw new IllegalArgumentException("Cannot schedule a timer with delay < 1 ms");
+    }
+    if (initialDelay < 0) {
+      throw new IllegalArgumentException("Cannot schedule a timer with initialDelay < 0");
+    }
+    long timerId = timeoutCounter.getAndIncrement();
+    InternalTimerHandler task = new InternalTimerHandler(timerId, handler, periodic, context);
+    timeouts.put(timerId, task);
+    if (addCloseHook) {
+      context.addCloseHook(task);
+    }
+    EventLoop el = context.eventLoop();
+    if (periodic) {
+      task.future = el.scheduleAtFixedRate(task, initialDelay, delay, timeUnit);
+    } else {
+      task.future = el.schedule(task, delay, timeUnit);
+    }
+    return task.id;
+  }
+
+  public long scheduleTimeout(ContextInternal context,
+                                              boolean periodic,
+                                              long delay,
+                                              TimeUnit timeUnit,
+                                              boolean addCloseHook,
+                                              Handler<Long> handler) {
+    return scheduleTimeout(context, periodic, delay, delay, timeUnit, addCloseHook, handler);
+  }
+
+  public ContextInternal getContext() {
+    ContextInternal context = ContextInternal.current();
+    if (context != null && context.owner() == this) {
+      return context;
+    } else {
+      WeakReference<ContextInternal> ref = stickyContext.get();
+      return ref != null ? ref.get() : null;
+    }
+  }
+
+  @Override
+  public synchronized Future<Void> close() {
+    // Create this promise purposely without a context because the close operation will close thread pools
+    if (closed) {
+      // Just call the handler directly since pools shutdown
+      return Future.succeededFuture();
+    }
+    closed = true;
+    Future<Void> fut = closeFuture
+      .close();
+    Future<Void> val = fut;
+    Promise<Void> p = Promise.promise();
+    val.onComplete(ar -> {
+        if (ar.succeeded()) {
+          p.complete();
+        } else {
+          p.fail(ar.cause());
+        }
+    });
+    return p.future();
+  }
+
+  /**
+   * Timers are stored in the {@link #timeouts} map at creation time.
+   * <p/>
+   * Timers are removed from the {@link #timeouts} map when they are cancelled or are fired. The thread
+   * removing the timer successfully owns the timer termination (i.e cancel or timer) to avoid race conditions
+   * between timeout and cancellation.
+   * <p/>
+   * This class does not rely on the internal {@link #future} for the termination to handle the worker case
+   * since the actual timer {@link #handler} execution is scheduled when the {@link #future} executes.
+   */
+  class InternalTimerHandler implements Handler<Void>, Closeable, Runnable {
+
+    private final Handler<Long> handler;
+    private final boolean periodic;
+    private final long id;
+    private final ContextInternal context;
+    private final AtomicBoolean disposed = new AtomicBoolean();
+    private volatile java.util.concurrent.Future<?> future;
+
+    InternalTimerHandler(long id, Handler<Long> runnable, boolean periodic, ContextInternal context) {
+      this.context = context;
+      this.id = id;
+      this.handler = runnable;
+      this.periodic = periodic;
+    }
+
+    @Override
+    public void run() {
+      context.emit(this);
+    }
+
+    public void handle(Void v) {
+      if (periodic) {
+        if (!disposed.get()) {
+          handler.handle(id);
+        }
+      } else if (disposed.compareAndSet(false, true)) {
+        timeouts.remove(id);
+        try {
+          handler.handle(id);
+        } finally {
+          // Clean up after it's fired
+          context.removeCloseHook(this);
+        }
+      }
+    }
+
+    private boolean cancel() {
+      boolean cancelled = tryCancel();
+      if (cancelled) {
+        context.removeCloseHook(this);
+      }
+      return cancelled;
+    }
+
+    private boolean tryCancel() {
+      if  (disposed.compareAndSet(false, true)) {
+        timeouts.remove(id);
+        future.cancel(false);
+        return true;
+      } else {
+        return false;
+      }
+    }
+
+    // Called via Context close hook when Verticle is undeployed
+    public void close(Promise<Void> completion) {
+      tryCancel();
+      completion.complete();
+    }
+  }
+
+  private static ThreadFactory createThreadFactory(AsyncThreadFactory threadFactory, Boolean useDaemonThread, long maxExecuteTime, TimeUnit maxExecuteTimeUnit, String prefix, boolean worker) {
+    AtomicInteger threadCount = new AtomicInteger(0);
+    return runnable -> {
+      AsyncThread thread = threadFactory.newVertxThread(runnable, prefix + threadCount.getAndIncrement(), worker, maxExecuteTime, maxExecuteTimeUnit);
+      if (useDaemonThread != null && thread.isDaemon() != useDaemonThread) {
+        thread.setDaemon(useDaemonThread);
+      }
+      return thread;
+    };
+  }
+
+  @Override
+  public Async exceptionHandler(Handler<Throwable> handler) {
+    exceptionHandler = handler;
+    return this;
+  }
+
+  @Override
+  public Handler<Throwable> exceptionHandler() {
+    return exceptionHandler;
+  }
+
+  @Override
+  public CloseFuture closeFuture() {
+    return closeFuture;
+  }
+
+  private CloseFuture resolveCloseFuture() {
+    ContextInternal context = getContext();
+    return context != null ? context.closeFuture() : closeFuture;
+  }
+
+  /**
+   * Execute the {@code task} disabling the thread-local association for the duration
+   * of the execution. {@link Async#currentContext()} will return {@code null},
+   * @param task the task to execute
+   * @throws IllegalStateException if the current thread is not a Async thread
+   */
+  void executeIsolated(Handler<Void> task) {
+    if (Thread.currentThread() instanceof AsyncThread) {
+      ContextInternal prev = beginDispatch(null);
+      try {
+        task.handle(null);
+      } finally {
+        endDispatch(prev);
+      }
+    } else {
+      task.handle(null);
+    }
+  }
+
+  static class ContextDispatch {
+    ContextInternal context;
+    ClassLoader topLevelTCCL;
+  }
+
+  /**
+   * Begin the emission of a context event.
+   * <p>
+   * This is a low level interface that should not be used, instead {@link ContextInternal#dispatch(Object, Handler)}
+   * shall be used.
+   *
+   * @param context the context on which the event is emitted on
+   * @return the current context that shall be restored
+   */
+  ContextInternal beginDispatch(ContextInternal context) {
+    Thread thread = Thread.currentThread();
+    ContextInternal prev;
+    if (thread instanceof AsyncThread) {
+      AsyncThread asyncThread = (AsyncThread) thread;
+      prev = asyncThread.context;
+      asyncThread.executeStart();
+      asyncThread.context = context;
+      if (!disableTCCL) {
+        if (prev == null) {
+          asyncThread.topLevelTCCL = Thread.currentThread().getContextClassLoader();
+        }
+        if (context != null) {
+          thread.setContextClassLoader(context.classLoader());
+        }
+      }
+    } else {
+      prev = beginDispatch2(thread, context);
+    }
+    return prev;
+  }
+
+  private ContextInternal beginDispatch2(Thread thread, ContextInternal context) {
+    ContextDispatch current = nonContextDispatch.get();
+    ContextInternal prev;
+    if (current != null) {
+      prev = current.context;
+    } else {
+      current = new ContextDispatch();
+      nonContextDispatch.set(current);
+      prev = null;
+    }
+    current.context = context;
+    if (!disableTCCL) {
+      if (prev == null) {
+        current.topLevelTCCL = Thread.currentThread().getContextClassLoader();
+      }
+      thread.setContextClassLoader(context.classLoader());
+    }
+    return prev;
+  }
+
+  /**
+   * End the emission of a context task.
+   * <p>
+   * This is a low level interface that should not be used, instead {@link ContextInternal#dispatch(Object, Handler)}
+   * shall be used.
+   *
+   * @param prev the previous context thread to restore, might be {@code null}
+   */
+  void endDispatch(ContextInternal prev) {
+    Thread thread = Thread.currentThread();
+    if (thread instanceof AsyncThread) {
+      AsyncThread asyncThread = (AsyncThread) thread;
+      asyncThread.context = prev;
+      if (!disableTCCL) {
+        ClassLoader tccl;
+        if (prev == null) {
+          tccl = asyncThread.topLevelTCCL;
+          asyncThread.topLevelTCCL = null;
+        } else {
+          tccl = prev.classLoader();
+        }
+        Thread.currentThread().setContextClassLoader(tccl);
+      }
+      asyncThread.executeEnd();
+    } else {
+      endDispatch2(prev);
+    }
+  }
+
+  private void endDispatch2(ContextInternal prev) {
+    ClassLoader tccl;
+    ContextDispatch current = nonContextDispatch.get();
+    if (prev != null) {
+      current.context = prev;
+      tccl = prev.classLoader();
+    } else {
+      nonContextDispatch.remove();
+      tccl = current.topLevelTCCL;
+    }
+    if (!disableTCCL) {
+      Thread.currentThread().setContextClassLoader(tccl);
+    }
+  }
+
+  /*
+   *
+   * This class is optimised for performance when used on the same event loop that is was passed to the handler with.
+   * However it can be used safely from other threads.
+   *
+   * The internal state is protected using the synchronized keyword. If always used on the same event loop, then
+   * we benefit from biased locking which makes the overhead of synchronized near zero.
+   *
+   */
+  private class TimeoutStreamImpl implements TimeoutStream, Handler<Long> {
+
+    private final long initialDelay;
+    private final long delay;
+    private final boolean periodic;
+
+    private Long id;
+    private Handler<Long> handler;
+    private Handler<Void> endHandler;
+    private long demand;
+
+    public TimeoutStreamImpl(long delay, boolean periodic) {
+      this(delay, delay, periodic);
+    }
+
+    public TimeoutStreamImpl(long initialDelay, long delay, boolean periodic) {
+      this.initialDelay = initialDelay;
+      this.delay = delay;
+      this.periodic = periodic;
+      this.demand = Long.MAX_VALUE;
+    }
+
+    @Override
+    public synchronized void handle(Long event) {
+      try {
+        if (demand > 0) {
+          demand--;
+          handler.handle(event);
+        }
+      } finally {
+        if (!periodic && endHandler != null) {
+          endHandler.handle(null);
+        }
+      }
+    }
+
+    @Override
+    public synchronized TimeoutStream fetch(long amount) {
+      demand += amount;
+      if (demand < 0) {
+        demand = Long.MAX_VALUE;
+      }
+      return this;
+    }
+
+    @Override
+    public TimeoutStream exceptionHandler(Handler<Throwable> handler) {
+      return this;
+    }
+
+    @Override
+    public void cancel() {
+      if (id != null) {
+        AsyncImpl.this.cancelTimer(id);
+      }
+    }
+
+    @Override
+    public synchronized TimeoutStream handler(Handler<Long> handler) {
+      if (handler != null) {
+        if (id != null) {
+          throw new IllegalStateException();
+        }
+        ContextInternal ctx = getOrCreateContext();
+        this.handler = handler;
+        this.id = scheduleTimeout(ctx, periodic, initialDelay, delay, TimeUnit.MILLISECONDS, false, this);
+      } else {
+        cancel();
+      }
+      return this;
+    }
+
+    @Override
+    public synchronized TimeoutStream pause() {
+      demand = 0;
+      return this;
+    }
+
+    @Override
+    public synchronized TimeoutStream resume() {
+      demand = Long.MAX_VALUE;
+      return this;
+    }
+
+    @Override
+    public synchronized TimeoutStream endHandler(Handler<Void> endHandler) {
+      this.endHandler = endHandler;
+      return this;
+    }
+  }
+
+}

src/main/java/org/xbib/event/async/impl/AsyncInternal.java

@@ -0,0 +1,52 @@
+package org.xbib.event.async.impl;
+
+import org.xbib.event.async.Async;
+import org.xbib.event.async.Future;
+import org.xbib.event.async.Handler;
+import org.xbib.event.async.Promise;
+import org.xbib.event.async.impl.future.PromiseInternal;
+
+/**
+ * This interface provides services for internal use only.
+ * It is not part of the public API and should not be used by
+ * developers.
+ */
+public interface AsyncInternal extends Async {
+
+  /**
+   * @return a promise associated with the context returned by {@link #getOrCreateContext()}.
+   */
+  <T> PromiseInternal<T> promise();
+
+  /**
+   * @return a promise associated with the context returned by {@link #getOrCreateContext()} or the {@code handler}
+   *         if that handler is already an instance of {@code PromiseInternal}
+   */
+  <T> PromiseInternal<T> promise(Promise<T> promise);
+
+  @Override
+  ContextInternal getOrCreateContext();
+
+  WorkerPool getWorkerPool();
+
+  WorkerPool getInternalWorkerPool();
+
+  /**
+   * Get the current context
+   * @return the context
+   */
+  ContextInternal getContext();
+
+  default <T> Future<T> executeBlockingInternal(Handler<Promise<T>> blockingCodeHandler) {
+    ContextInternal context = getOrCreateContext();
+    return context.executeBlockingInternal(blockingCodeHandler);
+  }
+
+  default <T> Future<T> executeBlockingInternal(Handler<Promise<T>> blockingCodeHandler, boolean ordered) {
+    ContextInternal context = getOrCreateContext();
+    return context.executeBlockingInternal(blockingCodeHandler, ordered);
+  }
+
+  CloseFuture closeFuture();
+
+}

src/main/java/org/xbib/event/async/impl/AsyncThread.java

@@ -0,0 +1,56 @@
+package org.xbib.event.async.impl;
+
+import org.xbib.event.thread.FastThreadLocalThread;
+import org.xbib.event.thread.ThreadInfo;
+
+import java.util.concurrent.TimeUnit;
+
+public class AsyncThread extends FastThreadLocalThread {
+
+  private final boolean worker;
+  final ThreadInfo info;
+  ContextInternal context;
+  ClassLoader topLevelTCCL;
+
+  public AsyncThread(Runnable target, String name, boolean worker, long maxExecTime, TimeUnit maxExecTimeUnit) {
+    super(target, name);
+    this.worker = worker;
+    this.info = new ThreadInfo(maxExecTimeUnit, maxExecTime);
+  }
+
+  /**
+   * @return the current context of this thread, this method must be called from the current thread
+   */
+  ContextInternal context() {
+    return context;
+  }
+
+  void executeStart() {
+    if (context == null) {
+      info.startTime = System.nanoTime();
+    }
+  }
+
+  void executeEnd() {
+    if (context == null) {
+      info.startTime = 0;
+    }
+  }
+
+  public long startTime() {
+    return info.startTime;
+  }
+
+  public boolean isWorker() {
+    return worker;
+  }
+
+  public long maxExecTime() {
+    return info.maxExecTime;
+  }
+
+  public TimeUnit maxExecTimeUnit() {
+    return info.maxExecTimeUnit;
+  }
+
+}

src/main/java/org/xbib/event/async/impl/CloseFuture.java

@@ -0,0 +1,176 @@
+package org.xbib.event.async.impl;
+
+import org.xbib.event.async.Closeable;
+import org.xbib.event.async.Future;
+import org.xbib.event.async.Promise;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/**
+ * A close future object is a state machine managing the closing sequence of a resource. A close future can be closed
+ * explicitly with the {@link #close()} method or when the future is unreachable in order to release the resource.
+ *
+ * <p> A closed future holds a set of nested {@link Closeable} that are processed when the future is closed. When a close
+ * future is closed, nested {@link Closeable} will be closed and the close future will notify the completion of the close
+ * sequence after the nested closeables are closed.
+ */
+public class CloseFuture extends NestedCloseable implements Closeable {
+
+  private final Logger log;
+  private final Promise<Void> promise = Promise.promise();
+  private boolean closed;
+  private Map<Closeable, CloseFuture> children;
+
+  public CloseFuture() {
+    this(null);
+  }
+
+  public CloseFuture(Logger log) {
+    this.log = log;
+  }
+
+  /**
+   * Add a {@code child} closeable, notified when this instance is closed.
+   *
+   * @param child the child closeable to add
+   */
+  public synchronized void add(Closeable child) {
+    if (closed) {
+      throw new IllegalStateException();
+    }
+    if (child instanceof NestedCloseable) {
+      NestedCloseable base = (NestedCloseable) child;
+      synchronized (base) {
+        if (base.owner != null) {
+          throw new IllegalStateException();
+        }
+        base.owner = this;
+      }
+    }
+    if (children == null) {
+      children = new HashMap<>();
+    }
+    children.put(child, this);
+  }
+
+  /**
+   * Remove an existing {@code nested} closeable.
+   *
+   * @param nested the closeable to remove
+   */
+  public boolean remove(Closeable nested) {
+    if (nested instanceof NestedCloseable) {
+      NestedCloseable base = (NestedCloseable) nested;
+      synchronized (base) {
+        if (base.owner == this) {
+          base.owner = null;
+        }
+      }
+    }
+    synchronized (this) {
+      if (children != null) {
+        return children.remove(nested) != null;
+      }
+    }
+    return false;
+  }
+
+  /**
+   * @return whether the future is closed.
+   */
+  public synchronized boolean isClosed() {
+    return closed;
+  }
+
+  /**
+   * @return the future completed after completion of all close hooks.
+   */
+  public Future<Void> future() {
+    return promise.future();
+  }
+
+  /**
+   * Run all close hooks, after completion of all hooks, the future is closed.
+   *
+   * @return the future completed after completion of all close hooks
+   */
+  public Future<Void> close() {
+    synchronized (this) {
+      if (closed) {
+        return promise.future();
+      }
+      closed = true;
+    }
+    cascadeClose();
+    return promise.future();
+  }
+
+  private void cascadeClose() {
+    List<Closeable> toClose = Collections.emptyList();
+    synchronized (this) {
+      if (children != null) {
+        toClose = new ArrayList<>(children.keySet());
+      }
+      children = null;
+    }
+    // We want an immutable version of the list holding strong references to avoid racing against finalization
+    int num = toClose.size();
+    if (num > 0) {
+      AtomicInteger count = new AtomicInteger();
+      for (Closeable hook : toClose) {
+        // Clear the reference before notifying to avoid a callback to this
+        if  (hook instanceof NestedCloseable) {
+          NestedCloseable base = (NestedCloseable) hook;
+          synchronized (base) {
+            base.owner = null;
+          }
+        }
+        Promise<Void> p = Promise.promise();
+        p.future().onComplete(ar -> {
+          if (count.incrementAndGet() == num) {
+            unregisterFromOwner();
+            promise.complete();
+          }
+        });
+        try {
+          hook.close(p);
+        } catch (Throwable t) {
+          if (log != null) {
+            log.log(Level.WARNING, "Failed to run close hook", t);
+          }
+          p.tryFail(t);
+        }
+      }
+    } else {
+      unregisterFromOwner();
+      promise.complete();
+    }
+  }
+
+  private void unregisterFromOwner() {
+    CloseFuture owner;
+    synchronized (this) {
+      owner = super.owner;
+    }
+    if (owner != null) {
+      owner.remove(this);
+    }
+  }
+
+  /**
+   * Run the close hooks, this method should not be called directly instead it should be called when
+   * this close future is added to another close future.
+   *
+   * @param promise called when all hooks have been executed
+   */
+  public void close(Promise<Void> promise) {
+    close().onComplete(promise);
+  }
+}

src/main/java/org/xbib/event/async/impl/ContextBase.java

@@ -0,0 +1,189 @@
+package org.xbib.event.async.impl;
+
+import org.xbib.event.async.Context;
+import org.xbib.event.async.Future;
+import org.xbib.event.async.Handler;
+import org.xbib.event.async.Promise;
+import org.xbib.event.loop.EventLoop;
+
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.Executor;
+import java.util.concurrent.RejectedExecutionException;
+
+/**
+ * A base class for {@link Context} implementations.
+ *
+ */
+public abstract class ContextBase implements ContextInternal {
+
+  private final AsyncInternal owner;
+  private final CloseFuture closeFuture;
+  private final ClassLoader tccl;
+  private final EventLoop eventLoop;
+  private ConcurrentMap<Object, Object> data;
+  private ConcurrentMap<Object, Object> localData;
+  private volatile Handler<Throwable> exceptionHandler;
+  final TaskQueue internalOrderedTasks;
+  final WorkerPool internalWorkerPool;
+  final WorkerPool workerPool;
+  final TaskQueue orderedTasks;
+
+  protected ContextBase(AsyncInternal asyncInternal,
+                        EventLoop eventLoop,
+                        WorkerPool internalWorkerPool,
+                        WorkerPool workerPool,
+                        CloseFuture closeFuture,
+                        ClassLoader tccl) {
+    this.eventLoop = eventLoop;
+    this.tccl = tccl;
+    this.owner = asyncInternal;
+    this.workerPool = workerPool;
+    this.closeFuture = closeFuture;
+    this.internalWorkerPool = internalWorkerPool;
+    this.orderedTasks = new TaskQueue();
+    this.internalOrderedTasks = new TaskQueue();
+  }
+
+  @Override
+  public CloseFuture closeFuture() {
+    return closeFuture;
+  }
+
+  public EventLoop eventLoop() {
+    return eventLoop;
+  }
+
+  public AsyncInternal owner() {
+    return owner;
+  }
+
+  @Override
+  public <T> Future<T> executeBlockingInternal(Handler<Promise<T>> action) {
+    return executeBlocking(this, action, internalWorkerPool, internalOrderedTasks);
+  }
+
+  @Override
+  public <T> Future<T> executeBlockingInternal(Handler<Promise<T>> action, boolean ordered) {
+    return executeBlocking(this, action, internalWorkerPool, ordered ? internalOrderedTasks : null);
+  }
+
+  @Override
+  public <T> Future<T> executeBlocking(Handler<Promise<T>> blockingCodeHandler, boolean ordered) {
+    return executeBlocking(this, blockingCodeHandler, workerPool, ordered ? orderedTasks : null);
+  }
+
+  @Override
+  public <T> Future<T> executeBlocking(Handler<Promise<T>> blockingCodeHandler, TaskQueue queue) {
+    return executeBlocking(this, blockingCodeHandler, workerPool, queue);
+  }
+
+  static <T> Future<T> executeBlocking(ContextInternal context, Handler<Promise<T>> blockingCodeHandler,
+      WorkerPool workerPool, TaskQueue queue) {
+    Promise<T> promise = context.promise();
+    Future<T> fut = promise.future();
+    try {
+      Runnable command = () -> {
+        Object execMetric = null;
+        context.dispatch(promise, f -> {
+          try {
+            blockingCodeHandler.handle(promise);
+          } catch (Throwable e) {
+            promise.tryFail(e);
+          }
+        });
+      };
+      Executor exec = workerPool.executor();
+      if (queue != null) {
+        queue.execute(command, exec);
+      } else {
+        exec.execute(command);
+      }
+    } catch (RejectedExecutionException e) {
+      throw e;
+    }
+    return fut;
+  }
+
+  @Override
+  public ClassLoader classLoader() {
+    return tccl;
+  }
+
+  @Override
+  public WorkerPool workerPool() {
+    return workerPool;
+  }
+
+  @Override
+  public synchronized ConcurrentMap<Object, Object> contextData() {
+    if (data == null) {
+      data = new ConcurrentHashMap<>();
+    }
+    return data;
+  }
+
+  @Override
+  public synchronized ConcurrentMap<Object, Object> localContextData() {
+    if (localData == null) {
+      localData = new ConcurrentHashMap<>();
+    }
+    return localData;
+  }
+
+  public void reportException(Throwable t) {
+    Handler<Throwable> handler = exceptionHandler;
+    if (handler == null) {
+      handler = owner.exceptionHandler();
+    }
+    if (handler != null) {
+      handler.handle(t);
+    } else {
+      throw new RuntimeException("Unhandled exception", t);
+    }
+  }
+
+  @Override
+  public Context exceptionHandler(Handler<Throwable> handler) {
+    exceptionHandler = handler;
+    return this;
+  }
+
+  @Override
+  public Handler<Throwable> exceptionHandler() {
+    return exceptionHandler;
+  }
+
+  @Override
+  public final void runOnContext(Handler<Void> action) {
+    runOnContext(this, action);
+  }
+
+  protected abstract void runOnContext(ContextInternal ctx, Handler<Void> action);
+
+  @Override
+  public void execute(Runnable task) {
+    execute(this, task);
+  }
+
+  protected abstract <T> void execute(ContextInternal ctx, Runnable task);
+
+  @Override
+  public final <T> void execute(T argument, Handler<T> task) {
+    execute(this, argument, task);
+  }
+
+  protected abstract <T> void execute(ContextInternal ctx, T argument, Handler<T> task);
+
+  @Override
+  public <T> void emit(T argument, Handler<T> task) {
+    emit(this, argument, task);
+  }
+
+  protected abstract <T> void emit(ContextInternal ctx, T argument, Handler<T> task);
+
+  @Override
+  public ContextInternal duplicate() {
+    return new DuplicatedContext(this);
+  }
+}

src/main/java/org/xbib/event/async/impl/ContextInternal.java

@@ -0,0 +1,392 @@
+package org.xbib.event.async.impl;
+
+import org.xbib.event.async.*;
+import org.xbib.event.async.Context;
+import org.xbib.event.async.impl.future.FailedFuture;
+import org.xbib.event.async.impl.future.PromiseImpl;
+import org.xbib.event.async.impl.future.PromiseInternal;
+import org.xbib.event.async.impl.future.SucceededFuture;
+
+import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.Executor;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * This interface provides an api for internal use only
+ * It is not part of the public API and should not be used by
+ * developers.
+ */
+public interface ContextInternal extends Context {
+
+  /**
+   * @return the current context
+   */
+  static ContextInternal current() {
+    Thread thread = Thread.currentThread();
+    if (thread instanceof AsyncThread) {
+      return ((AsyncThread) thread).context();
+    } else {
+      AsyncImpl.ContextDispatch current = AsyncImpl.nonContextDispatch.get();
+      if (current != null) {
+        return current.context;
+      }
+    }
+    return null;
+  }
+
+  @Override
+  default void runOnContext(Handler<Void> action) {
+    executor().execute(() -> dispatch(action));
+  }
+
+  /**
+   * @return an executor that schedule a task on this context, the thread executing the task will not be associated with this context
+   */
+  Executor executor();
+
+  /**
+   * @return a {@link Promise} associated with this context
+   */
+  default <T> PromiseInternal<T> promise() {
+    return new PromiseImpl<>(this);
+  }
+
+  /**
+   * @return a {@link Promise} associated with this context or the {@code handler}
+   *         if that handler is already an instance of {@code PromiseInternal}
+   */
+  default <T> PromiseInternal<T> promise(Promise<T> p) {
+    if (p instanceof PromiseInternal) {
+      PromiseInternal<T> promise = (PromiseInternal<T>) p;
+      if (promise.context() != null) {
+        return promise;
+      }
+    }
+    PromiseInternal<T> promise = promise();
+    promise.future().onComplete(p);
+    return promise;
+  }
+
+  /**
+   * @return an empty succeeded {@link Future} associated with this context
+   */
+  default <T> Future<T> succeededFuture() {
+    return new SucceededFuture<>(this, null);
+  }
+
+  /**
+   * @return a succeeded {@link Future} of the {@code result} associated with this context
+   */
+  default <T> Future<T> succeededFuture(T result) {
+    return new SucceededFuture<>(this, result);
+  }
+
+  /**
+   * @return a {@link Future} failed with the {@code failure} associated with this context
+   */
+  default <T> Future<T> failedFuture(Throwable failure) {
+    return new FailedFuture<>(this, failure);
+  }
+
+  /**
+   * @return a {@link Future} failed with the {@code message} associated with this context
+   */
+  default <T> Future<T> failedFuture(String message) {
+    return new FailedFuture<>(this, message);
+  }
+
+  /**
+   * Like {@link #executeBlocking(Handler, boolean)} but uses the {@code queue} to order the tasks instead
+   * of the internal queue of this context.
+   */
+  <T> Future<T> executeBlocking(Handler<Promise<T>> blockingCodeHandler, TaskQueue queue);
+
+  /**
+   * Execute an internal task on the internal blocking ordered executor.
+   */
+  <T> Future<T> executeBlockingInternal(Handler<Promise<T>> action);
+
+  /**
+   * Execute an internal task on the internal blocking ordered executor.
+   */
+  <T> Future<T> executeBlockingInternal(Handler<Promise<T>> action, boolean ordered);
+
+  /**
+   * @return the deployment associated with this context or {@code null}
+   */
+
+  @Override
+  AsyncInternal owner();
+
+  boolean inThread();
+
+  /**
+   * Emit the given {@code argument} event to the {@code task} and switch on this context if necessary, this also associates the
+   * current thread with the current context so {@link Async#currentContext()} returns this context.
+   * <br/>
+   * Any exception thrown from the {@literal task} will be reported on this context.
+   * <br/>
+   * Calling this method is equivalent to {@code execute(v -> dispatch(argument, task))}
+   *
+   * @param argument the {@code task} argument
+   * @param task the handler to execute with the {@code event} argument
+   */
+  <T> void emit(T argument, Handler<T> task);
+
+  /**
+   * @see #emit(Object, Handler)
+   */
+  default void emit(Handler<Void> task) {
+    emit(null, task);
+  }
+
+  /**
+   * @see #execute(Object, Handler)
+   */
+  default void execute(Handler<Void> task) {
+    execute(null, task);
+  }
+
+  /**
+   * Execute the {@code task} on this context, it will be executed according to the
+   * context concurrency model.
+   *
+   * @param task the task to execute
+   */
+  void execute(Runnable task);
+
+  /**
+   * Execute a {@code task} on this context, the task will be executed according to the
+   * context concurrency model.
+   *
+   * @param argument the {@code task} argument
+   * @param task the task to execute
+   */
+  <T> void execute(T argument, Handler<T> task);
+
+  /**
+   * @return whether the current thread is running on this context
+   */
+  default boolean isRunningOnContext() {
+    return current() == this && inThread();
+  }
+
+  /**
+   * @see #dispatch(Handler)
+   */
+  default void dispatch(Runnable handler) {
+    ContextInternal prev = beginDispatch();
+    try {
+      handler.run();
+    } catch (Throwable t) {
+      reportException(t);
+    } finally {
+      endDispatch(prev);
+    }
+  }
+
+  /**
+   * @see #dispatch(Object, Handler)
+   */
+  default void dispatch(Handler<Void> handler) {
+    dispatch(null, handler);
+  }
+
+  /**
+   * Dispatch an {@code event} to the {@code handler} on this context.
+   * <p>
+   * The handler is executed directly by the caller thread which must be a context thread.
+   * <p>
+   * The handler execution is monitored by the blocked thread checker.
+   * <p>
+   * This context is thread-local associated during the task execution.
+   *
+   * @param event the event for the {@code handler}
+   * @param handler the handler to execute with the {@code event}
+   */
+  default <E> void dispatch(E event, Handler<E> handler) {
+    ContextInternal prev = beginDispatch();
+    try {
+      handler.handle(event);
+    } catch (Throwable t) {
+      reportException(t);
+    } finally {
+      endDispatch(prev);
+    }
+  }
+
+  /**
+   * Begin the execution of a task on this context.
+   * <p>
+   * The task execution is monitored by the blocked thread checker.
+   * <p>
+   * This context is thread-local associated during the task execution.
+   * <p>
+   * You should not use this API directly, instead you should use {@link #dispatch(Object, Handler)}
+   *
+   * @return the previous context that shall be restored after or {@code null} if there is none
+   * @throws IllegalStateException when the current thread of execution cannot execute this task
+   */
+  default ContextInternal beginDispatch() {
+    AsyncImpl async = (AsyncImpl) owner();
+    return async.beginDispatch(this);
+  }
+
+  /**
+   * End the execution of a task on this context, see {@link #beginDispatch()}
+   * <p>
+   * You should not use this API directly, instead you should use {@link #dispatch(Object, Handler)}
+   *
+   * @param previous the previous context to restore or {@code null} if there is none
+   * @throws IllegalStateException when the current thread of execution cannot execute this task
+   */
+  default void endDispatch(ContextInternal previous) {
+    AsyncImpl async = (AsyncImpl) owner();
+    async.endDispatch(previous);
+  }
+
+  /**
+   * Report an exception to this context synchronously.
+   * <p>
+   * The exception handler will be called when there is one, otherwise the exception will be logged.
+   *
+   * @param t the exception to report
+   */
+  void reportException(Throwable t);
+
+  /**
+   * @return the {@link ConcurrentMap} used to store context data
+   * @see Context#get(Object)
+   * @see Context#put(Object, Object)
+   */
+  ConcurrentMap<Object, Object> contextData();
+
+  @SuppressWarnings("unchecked")
+  @Override
+  default <T> T get(Object key) {
+    return (T) contextData().get(key);
+  }
+
+  @Override
+  default void put(Object key, Object value) {
+    contextData().put(key, value);
+  }
+
+  @Override
+  default boolean remove(Object key) {
+    return contextData().remove(key) != null;
+  }
+
+  /**
+   * @return the {@link ConcurrentMap} used to store local context data
+   */
+  ConcurrentMap<Object, Object> localContextData();
+
+  @SuppressWarnings("unchecked")
+  @Override
+  default <T> T getLocal(Object key) {
+    return (T) localContextData().get(key);
+  }
+
+  @Override
+  default void putLocal(Object key, Object value) {
+    localContextData().put(key, value);
+  }
+
+  @Override
+  default boolean removeLocal(Object key) {
+    return localContextData().remove(key) != null;
+  }
+
+  /**
+   * @return the classloader associated with this context
+   */
+  ClassLoader classLoader();
+
+  /**
+   * @return the context worker pool
+   */
+  WorkerPool workerPool();
+
+
+  /**
+   * Returns a context sharing with this context
+   * <ul>
+   *   <li>the same concurrency</li>
+   *   <li>the same exception handler</li>
+   *   <li>the same context data</li>
+   *   <li>the same deployment</li>
+   *   <li>the same config</li>
+   *   <li>the same classloader</li>
+   * </ul>
+   * <p>
+   * The duplicate context has its own
+   * <ul>
+   *   <li>local context data</li>
+   *   <li>worker task queue</li>
+   * </ul>
+   *
+   * @return a duplicate of this context
+   */
+  ContextInternal duplicate();
+
+  /**
+   * Like {@link Async#setPeriodic(long, Handler)} except the periodic timer will fire on this context and the
+   * timer will not be associated with the context close hook.
+   */
+  default long setPeriodic(long delay, Handler<Long> handler) {
+    AsyncImpl owner = (AsyncImpl) owner();
+    return owner.scheduleTimeout(this, true, delay, TimeUnit.MILLISECONDS, false, handler);
+  }
+
+  /**
+   * Like {@link Async#setTimer(long, Handler)} except the timer will fire on this context and the timer
+   * will not be associated with the context close hook.
+   */
+  default long setTimer(long delay, Handler<Long> handler) {
+    AsyncImpl owner = (AsyncImpl) owner();
+    return owner.scheduleTimeout(this, false, delay, TimeUnit.MILLISECONDS, false, handler);
+  }
+
+  CloseFuture closeFuture();
+
+  /**
+   * Add a close hook.
+   *
+   * <p> The {@code hook} will be called when the associated resource needs to be released.
+   *
+   * @param hook the close hook
+   */
+  default void addCloseHook(Closeable hook) {
+    closeFuture().add(hook);
+  }
+
+  /**
+   * Remove a close hook.
+   *
+   * <p> This is called when the resource is released explicitly and does not need anymore a managed close.
+   *
+   * @param hook the close hook
+   */
+  default void removeCloseHook(Closeable hook) {
+    closeFuture().remove(hook);
+  }
+
+  /**
+   * Returns the original context, a duplicate context returns the wrapped context otherwise this instance is returned.
+   *
+   * @return the wrapped context
+   */
+  default ContextInternal unwrap() {
+    return this;
+  }
+
+  /**
+   * Returns {@code true} if this context is a duplicated context.
+   *
+   * @return {@code true} if this context is a duplicated context, {@code false} otherwise.
+   */
+  default boolean isDuplicate() {
+    return false;
+  }
+}

src/main/java/org/xbib/event/async/impl/DuplicatedContext.java

@@ -0,0 +1,161 @@
+package org.xbib.event.async.impl;
+
+import org.xbib.event.async.Context;
+import org.xbib.event.async.Future;
+import org.xbib.event.async.Handler;
+import org.xbib.event.async.Promise;
+import org.xbib.event.loop.EventLoop;
+
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.Executor;
+
+/**
+ * A context that forwards most operations to a delegate. This context
+ *
+ * <ul>
+ *   <li>maintains its own ordered task queue, ordered execute blocking are ordered on this
+ *  context instead of the delegate.</li>
+ *  <li>maintains its own local data instead of the delegate.</li>
+ * </ul>
+ */
+class DuplicatedContext implements ContextInternal {
+
+  protected final ContextBase delegate;
+  private ConcurrentMap<Object, Object> localData;
+
+  DuplicatedContext(ContextBase delegate) {
+    this.delegate = delegate;
+  }
+
+  @Override
+  public boolean inThread() {
+    return delegate.inThread();
+  }
+
+  @Override
+  public final CloseFuture closeFuture() {
+    return delegate.closeFuture();
+  }
+
+
+  @Override
+  public final Context exceptionHandler(Handler<Throwable> handler) {
+    delegate.exceptionHandler(handler);
+    return this;
+  }
+
+  @Override
+  public Executor executor() {
+    return delegate.executor();
+  }
+
+  @Override
+  public final Handler<Throwable> exceptionHandler() {
+    return delegate.exceptionHandler();
+  }
+
+  public final EventLoop eventLoop() {
+    return delegate.eventLoop();
+  }
+
+  @Override
+  public final AsyncInternal owner() {
+    return delegate.owner();
+  }
+
+  @Override
+  public final ClassLoader classLoader() {
+    return delegate.classLoader();
+  }
+
+  @Override
+  public WorkerPool workerPool() {
+    return delegate.workerPool();
+  }
+
+  @Override
+  public final void reportException(Throwable t) {
+    delegate.reportException(t);
+  }
+
+  @Override
+  public final ConcurrentMap<Object, Object> contextData() {
+    return delegate.contextData();
+  }
+
+  @Override
+  public final ConcurrentMap<Object, Object> localContextData() {
+    synchronized (this) {
+      if (localData == null) {
+        localData = new ConcurrentHashMap<>();
+      }
+      return localData;
+    }
+  }
+
+  @Override
+  public final <T> Future<T> executeBlockingInternal(Handler<Promise<T>> action) {
+    return ContextBase.executeBlocking(this, action, delegate.internalWorkerPool, delegate.internalOrderedTasks);
+  }
+
+  @Override
+  public final <T> Future<T> executeBlockingInternal(Handler<Promise<T>> action, boolean ordered) {
+    return ContextBase.executeBlocking(this, action, delegate.internalWorkerPool, ordered ? delegate.internalOrderedTasks : null);
+  }
+
+  @Override
+  public final <T> Future<T> executeBlocking(Handler<Promise<T>> action, boolean ordered) {
+    return ContextBase.executeBlocking(this, action, delegate.workerPool, ordered ? delegate.orderedTasks : null);
+  }
+
+  @Override
+  public final <T> Future<T> executeBlocking(Handler<Promise<T>> blockingCodeHandler, TaskQueue queue) {
+    return ContextBase.executeBlocking(this, blockingCodeHandler, delegate.workerPool, queue);
+  }
+
+  @Override
+  public final void runOnContext(Handler<Void> action) {
+    delegate.runOnContext(this, action);
+  }
+
+  @Override
+  public final <T> void execute(T argument, Handler<T> task) {
+    delegate.execute(this, argument, task);
+  }
+
+  @Override
+  public <T> void emit(T argument, Handler<T> task) {
+    delegate.emit(this, argument, task);
+  }
+
+  @Override
+  public void execute(Runnable task) {
+    delegate.execute(this, task);
+  }
+
+  @Override
+  public boolean isEventLoopContext() {
+    return delegate.isEventLoopContext();
+  }
+
+  @Override
+  public boolean isWorkerContext() {
+    return delegate.isWorkerContext();
+  }
+
+  @Override
+  public ContextInternal duplicate() {
+    return new DuplicatedContext(delegate);
+  }
+
+  @Override
+  public ContextInternal unwrap() {
+    return delegate;
+  }
+
+  @Override
+  public boolean isDuplicate() {
+    return true;
+  }
+}

src/main/java/org/xbib/event/async/impl/EventLoopContext.java

@@ -0,0 +1,92 @@
+package org.xbib.event.async.impl;
+
+import org.xbib.event.async.Handler;
+import org.xbib.event.loop.EventLoop;
+
+import java.util.concurrent.Executor;
+import java.util.concurrent.RejectedExecutionException;
+
+public class EventLoopContext extends ContextBase {
+
+  EventLoopContext(AsyncInternal asyncInternal,
+                   EventLoop eventLoop,
+                   WorkerPool internalBlockingPool,
+                   WorkerPool workerPool,
+                   CloseFuture closeFuture,
+                   ClassLoader tccl) {
+    super(asyncInternal, eventLoop, internalBlockingPool, workerPool, closeFuture, tccl);
+  }
+
+  @Override
+  public Executor executor() {
+    return eventLoop();
+  }
+
+  @Override
+  protected void runOnContext(ContextInternal ctx, Handler<Void> action) {
+    try {
+      eventLoop().execute(() -> ctx.dispatch(action));
+    } catch (RejectedExecutionException ignore) {
+      // Pool is already shut down
+    }
+  }
+
+  @Override
+  protected <T> void emit(ContextInternal ctx, T argument, Handler<T> task) {
+    EventLoop eventLoop = eventLoop();
+    if (eventLoop.inEventLoop()) {
+      ContextInternal prev = ctx.beginDispatch();
+      try {
+        task.handle(argument);
+      } catch (Throwable t) {
+        reportException(t);
+      } finally {
+        ctx.endDispatch(prev);
+      }
+    } else {
+      eventLoop.execute(() -> emit(ctx, argument, task));
+    }
+  }
+
+  /**
+   * <ul>
+   *   <li>When the current thread is event-loop thread of this context the implementation will execute the {@code task} directly</li>
+   *   <li>Otherwise the task will be scheduled on the event-loop thread for execution</li>
+   * </ul>
+   */
+  @Override
+  protected <T> void execute(ContextInternal ctx, T argument, Handler<T> task) {
+    EventLoop eventLoop = eventLoop();
+    if (eventLoop.inEventLoop()) {
+      task.handle(argument);
+    } else {
+      eventLoop.execute(() -> task.handle(argument));
+    }
+  }
+
+  @Override
+  protected <T> void execute(ContextInternal ctx, Runnable task) {
+    EventLoop eventLoop = eventLoop();
+    if (eventLoop.inEventLoop()) {
+      task.run();
+    } else {
+      eventLoop.execute(task);
+    }
+  }
+
+  @Override
+  public boolean isEventLoopContext() {
+    return true;
+  }
+
+  @Override
+  public boolean isWorkerContext() {
+    return false;
+  }
+
+  @Override
+  public boolean inThread() {
+    return eventLoop().inEventLoop();
+  }
+
+}

src/main/java/org/xbib/event/async/impl/NestedCloseable.java

@@ -0,0 +1,10 @@
+package org.xbib.event.async.impl;
+
+/**
+ * Keeps a reference to an owner close future so we can unregister from it when the closeable is closed.
+ */
+abstract class NestedCloseable {
+
+  CloseFuture owner;
+
+}

src/main/java/org/xbib/event/async/impl/TaskQueue.java

@@ -0,0 +1,88 @@
+package org.xbib.event.async.impl;
+
+import java.util.LinkedList;
+import java.util.concurrent.Executor;
+import java.util.concurrent.RejectedExecutionException;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/**
+ * A task queue that always run all tasks in order. The executor to run the tasks is passed
+ * when the tasks are executed, this executor is not guaranteed to be used, as if several
+ * tasks are queued, the original thread will be used.
+ *
+ * More specifically, any call B to the {@link #execute(Runnable, Executor)} method that happens-after another call A to the
+ * same method, will result in B's task running after A's.
+ *
+ */
+public class TaskQueue {
+
+  static final Logger log = Logger.getLogger(TaskQueue.class.getName());
+
+  private static class Task {
+
+    private final Runnable runnable;
+    private final Executor exec;
+
+    public Task(Runnable runnable, Executor exec) {
+      this.runnable = runnable;
+      this.exec = exec;
+    }
+  }
+
+  // @protectedby tasks
+  private final LinkedList<Task> tasks = new LinkedList<>();
+
+  // @protectedby tasks
+  private Executor current;
+
+  private final Runnable runner;
+
+  public TaskQueue() {
+    runner = this::run;
+  }
+
+  private void run() {
+    for (; ; ) {
+      final Task task;
+      synchronized (tasks) {
+        task = tasks.poll();
+        if (task == null) {
+          current = null;
+          return;
+        }
+        if (task.exec != current) {
+          tasks.addFirst(task);
+          task.exec.execute(runner);
+          current = task.exec;
+          return;
+        }
+      }
+      try {
+        task.runnable.run();
+      } catch (Throwable t) {
+        log.log(Level.SEVERE, "Caught unexpected Throwable", t);
+      }
+    }
+  };
+
+  /**
+   * Run a task.
+   *
+   * @param task the task to run.
+   */
+  public void execute(Runnable task, Executor executor) {
+    synchronized (tasks) {
+      tasks.add(new Task(task, executor));
+      if (current == null) {
+        current = executor;
+        try {
+          executor.execute(runner);
+        } catch (RejectedExecutionException e) {
+          current = null;
+          throw e;
+        }
+      }
+    }
+  }
+}

src/main/java/org/xbib/event/async/impl/WorkerPool.java

@@ -0,0 +1,20 @@
+package org.xbib.event.async.impl;
+
+import java.util.concurrent.ExecutorService;
+
+public class WorkerPool {
+
+  private final ExecutorService pool;
+
+  public WorkerPool(ExecutorService pool) {
+    this.pool = pool;
+  }
+
+  public ExecutorService executor() {
+    return pool;
+  }
+
+  void close() {
+    pool.shutdownNow();
+  }
+}

src/main/java/org/xbib/event/async/impl/future/CompositeFutureImpl.java

@@ -0,0 +1,189 @@
+package org.xbib.event.async.impl.future;
+
+import org.xbib.event.async.AsyncResult;
+import org.xbib.event.async.CompositeFuture;
+import org.xbib.event.async.Future;
+import org.xbib.event.async.Handler;
+
+import java.util.function.Function;
+
+public class CompositeFutureImpl extends FutureImpl<CompositeFuture> implements CompositeFuture {
+
+  public static CompositeFuture all(Future<?>... results) {
+    CompositeFutureImpl composite = new CompositeFutureImpl(results);
+    int len = results.length;
+    for (Future<?> result : results) {
+      result.onComplete(ar -> {
+        if (ar.succeeded()) {
+          synchronized (composite) {
+            if (composite.count == len || ++composite.count != len) {
+              return;
+            }
+          }
+          composite.trySucceed();
+        } else {
+          synchronized (composite) {
+            if (composite.count == len) {
+              return;
+            }
+            composite.count = len;
+          }
+          composite.tryFail(ar.cause());
+        }
+      });
+    }
+    if (len == 0) {
+      composite.trySucceed();
+    }
+    return composite;
+  }
+
+  public static CompositeFuture any(Future<?>... results) {
+    CompositeFutureImpl composite = new CompositeFutureImpl(results);
+    int len = results.length;
+    for (Future<?> result : results) {
+      result.onComplete(ar -> {
+        if (ar.succeeded()) {
+          synchronized (composite) {
+            if (composite.count == len) {
+              return;
+            }
+            composite.count = len;
+          }
+          composite.trySucceed();
+        } else {
+          synchronized (composite) {
+            if (composite.count == len || ++composite.count != len) {
+              return;
+            }
+          }
+          composite.tryFail(ar.cause());
+        }
+      });
+    }
+    if (results.length == 0) {
+      composite.trySucceed();
+    }
+    return composite;
+  }
+
+  private static final Function<CompositeFuture, Object> ALL = cf -> {
+    int size = cf.size();
+    for (int i = 0;i < size;i++) {
+      if (!cf.succeeded(i)) {
+        return cf.cause(i);
+      }
+    }
+    return cf;
+  };
+
+  public static CompositeFuture join(Future<?>... results) {
+    return join(ALL, results);
+  }
+
+  private  static CompositeFuture join(Function<CompositeFuture, Object> pred, Future<?>... results) {
+    CompositeFutureImpl composite = new CompositeFutureImpl(results);
+    int len = results.length;
+    for (Future<?> result : results) {
+      result.onComplete(ar -> {
+        synchronized (composite) {
+          if (++composite.count < len) {
+            return;
+          }
+        }
+        composite.complete(pred.apply(composite));
+      });
+    }
+    if (len == 0) {
+      composite.trySucceed();
+    }
+    return composite;
+  }
+
+  private final Future[] results;
+  private int count;
+
+  private CompositeFutureImpl(Future<?>... results) {
+    this.results = results;
+  }
+
+  @Override
+  public Throwable cause(int index) {
+    return future(index).cause();
+  }
+
+  @Override
+  public boolean succeeded(int index) {
+    return future(index).succeeded();
+  }
+
+  @Override
+  public boolean failed(int index) {
+    return future(index).failed();
+  }
+
+  @Override
+  public boolean isComplete(int index) {
+    return future(index).isComplete();
+  }
+
+  @Override
+  public <T> T resultAt(int index) {
+    return this.<T>future(index).result();
+  }
+
+  private <T> Future<T> future(int index) {
+    if (index < 0 || index >= results.length) {
+      throw new IndexOutOfBoundsException();
+    }
+    return (Future<T>) results[index];
+  }
+
+  @Override
+  public int size() {
+    return results.length;
+  }
+
+  private void trySucceed() {
+    tryComplete(this);
+  }
+
+  private void fail(Throwable t) {
+    complete(t);
+  }
+
+  private void complete(Object result) {
+    if (result == this) {
+      tryComplete(this);
+    } else if (result instanceof Throwable) {
+      tryFail((Throwable) result);
+    }
+  }
+
+  @Override
+  public CompositeFuture onComplete(Handler<AsyncResult<CompositeFuture>> handler) {
+    return (CompositeFuture)super.onComplete(handler);
+  }
+
+  @Override
+  public CompositeFuture onSuccess(Handler<CompositeFuture> handler) {
+    return (CompositeFuture)super.onSuccess(handler);
+  }
+
+  @Override
+  public CompositeFuture onFailure(Handler<Throwable> handler) {
+    return (CompositeFuture)super.onFailure(handler);
+  }
+
+  @Override
+  protected void formatValue(Object value, StringBuilder sb) {
+    sb.append('(');
+    for (int i = 0;i < results.length;i++) {
+      if (i > 0) {
+        sb.append(',');
+      }
+      sb.append(results[i]);
+    }
+    sb.append(')');
+  }
+}

src/main/java/org/xbib/event/async/impl/future/Composition.java

@@ -0,0 +1,58 @@
+package org.xbib.event.async.impl.future;
+
+import org.xbib.event.async.Future;
+import org.xbib.event.async.impl.ContextInternal;
+
+import java.util.function.Function;
+
+/**
+ * Function compose transformation.
+ */
+class Composition<T, U> extends Operation<U> implements Listener<T> {
+
+  private final Function<T, Future<U>> successMapper;
+  private final Function<Throwable, Future<U>> failureMapper;
+
+  Composition(ContextInternal context, Function<T, Future<U>> successMapper, Function<Throwable, Future<U>> failureMapper) {
+    super(context);
+    this.successMapper = successMapper;
+    this.failureMapper = failureMapper;
+  }
+
+  @Override
+  public void onSuccess(T value) {
+    FutureInternal<U> future;
+    try {
+      future = (FutureInternal<U>) successMapper.apply(value);
+    } catch (Throwable e) {
+      tryFail(e);
+      return;
+    }
+    future.addListener(newListener());
+  }
+
+  @Override
+  public void onFailure(Throwable failure) {
+    FutureInternal<U> future;
+    try {
+      future = (FutureInternal<U>) failureMapper.apply(failure);
+    } catch (Throwable e) {
+      tryFail(e);
+      return;
+    }
+    future.addListener(newListener());
+  }
+
+  private Listener<U> newListener() {
+    return new Listener<U>() {
+      @Override
+      public void onSuccess(U value) {
+        tryComplete(value);
+      }
+      @Override
+      public void onFailure(Throwable failure) {
+        tryFail(failure);
+      }
+    };
+  }
+}

src/main/java/org/xbib/event/async/impl/future/Eventually.java

@@ -0,0 +1,62 @@
+package org.xbib.event.async.impl.future;
+
+
+import org.xbib.event.async.Future;
+import org.xbib.event.async.impl.ContextInternal;
+
+import java.util.function.Function;
+
+/**
+ * Eventually operation.
+ */
+class Eventually<T, U> extends Operation<T> implements Listener<T> {
+
+  private final Function<Void, Future<U>> mapper;
+
+  Eventually(ContextInternal context, Function<Void, Future<U>> mapper) {
+    super(context);
+    this.mapper = mapper;
+  }
+
+  @Override
+  public void onSuccess(T value) {
+    FutureInternal<U> future;
+    try {
+      future = (FutureInternal<U>) mapper.apply(null);
+    } catch (Throwable e) {
+      tryFail(e);
+      return;
+    }
+    future.addListener(new Listener<U>() {
+      @Override
+      public void onSuccess(U ignore) {
+        tryComplete(value);
+      }
+      @Override
+      public void onFailure(Throwable ignore) {
+        tryComplete(value);
+      }
+    });
+  }
+
+  @Override
+  public void onFailure(Throwable failure) {
+    FutureInternal<U> future;
+    try {
+      future = (FutureInternal<U>) mapper.apply(null);
+    } catch (Throwable e) {
+      tryFail(e);
+      return;
+    }
+    future.addListener(new Listener<>() {
+      @Override
+      public void onSuccess(U ignore) {
+        tryFail(failure);
+      }
+      @Override
+      public void onFailure(Throwable ignore) {
+        tryFail(failure);
+      }
+    });
+  }
+}

src/main/java/org/xbib/event/async/impl/future/FailedFuture.java

@@ -0,0 +1,127 @@
+package org.xbib.event.async.impl.future;
+
+import org.xbib.event.async.AsyncResult;
+import org.xbib.event.async.Future;
+import org.xbib.event.async.Handler;
+import org.xbib.event.async.NoStackTraceThrowable;
+import org.xbib.event.async.impl.ContextInternal;
+
+import java.util.function.Function;
+
+/**
+ * Failed future implementation.
+ */
+public final class FailedFuture<T> extends FutureBase<T> {
+
+  private final Throwable cause;
+
+  /**
+   * Create a future that has already failed
+   * @param t the throwable
+   */
+  public FailedFuture(Throwable t) {
+    this(null, t);
+  }
+
+  /**
+   * Create a future that has already failed
+   * @param t the throwable
+   */
+  public FailedFuture(ContextInternal context, Throwable t) {
+    super(context);
+    this.cause = t != null ? t : new NoStackTraceThrowable(null);
+  }
+
+  /**
+   * Create a future that has already failed
+   * @param failureMessage the failure message
+   */
+  public FailedFuture(String failureMessage) {
+    this(null, failureMessage);
+  }
+
+  /**
+   * Create a future that has already failed
+   * @param failureMessage the failure message
+   */
+  public FailedFuture(ContextInternal context, String failureMessage) {
+    this(context, new NoStackTraceThrowable(failureMessage));
+  }
+
+  @Override
+  public boolean isComplete() {
+    return true;
+  }
+
+  @Override
+  public Future<T> onComplete(Handler<AsyncResult<T>> handler) {
+    if (handler instanceof Listener) {
+      emitFailure(cause, (Listener<T>) handler);
+    } else if (context != null) {
+      context.emit(this, handler);
+    } else {
+      handler.handle(this);
+    }
+    return this;
+  }
+
+  @Override
+  public Future<T> onSuccess(Handler<T> handler) {
+    return this;
+  }
+
+  @Override
+  public Future<T> onFailure(Handler<Throwable> handler) {
+    if (context != null) {
+      context.emit(cause, handler);
+    } else {
+      handler.handle(cause);
+    }
+    return this;
+  }
+
+  @Override
+  public void addListener(Listener<T> listener) {
+    emitFailure(cause, listener);
+  }
+
+  @Override
+  public T result() {
+    return null;
+  }
+
+  @Override
+  public Throwable cause() {
+    return cause;
+  }
+
+  @Override
+  public boolean succeeded() {
+    return false;
+  }
+
+  @Override
+  public boolean failed() {
+    return true;
+  }
+
+  @Override
+  public <U> Future<U> map(Function<T, U> mapper) {
+    return (Future<U>) this;
+  }
+
+  @Override
+  public <V> Future<V> map(V value) {
+    return (Future<V>) this;
+  }
+
+  @Override
+  public Future<T> otherwise(T value) {
+    return new SucceededFuture<>(context, value);
+  }
+
+  @Override
+  public String toString() {
+    return "Future{cause=" + cause.getMessage() + "}";
+  }
+}

src/main/java/org/xbib/event/async/impl/future/FixedMapping.java

@@ -0,0 +1,26 @@
+package org.xbib.event.async.impl.future;
+
+import org.xbib.event.async.impl.ContextInternal;
+
+/**
+ * Map value transformation.
+ */
+class FixedMapping<T, U> extends Operation<U> implements Listener<T> {
+
+  private final U value;
+
+  FixedMapping(ContextInternal context, U value) {
+    super(context);
+    this.value = value;
+  }
+
+  @Override
+  public void onSuccess(T value) {
+    tryComplete(this.value);
+  }
+
+  @Override
+  public void onFailure(Throwable failure) {
+    tryFail(failure);
+  }
+}

src/main/java/org/xbib/event/async/impl/future/FixedOtherwise.java

@@ -0,0 +1,26 @@
+package org.xbib.event.async.impl.future;
+
+import org.xbib.event.async.impl.ContextInternal;
+
+/**
+ * Otherwise value transformation.
+ */
+class FixedOtherwise<T> extends Operation<T> implements Listener<T> {
+
+  private final T value;
+
+  FixedOtherwise(ContextInternal context, T value) {
+    super(context);
+    this.value = value;
+  }
+
+  @Override
+  public void onSuccess(T value) {
+    tryComplete(value);
+  }
+
+  @Override
+  public void onFailure(Throwable failure) {
+    tryComplete(value);
+  }
+}

src/main/java/org/xbib/event/async/impl/future/FutureBase.java

@@ -0,0 +1,119 @@
+package org.xbib.event.async.impl.future;
+
+import org.xbib.event.async.AsyncResult;
+import org.xbib.event.async.Future;
+import org.xbib.event.async.impl.ContextInternal;
+
+import java.util.Objects;
+import java.util.function.Function;
+
+/**
+ * Future base implementation.
+ */
+public abstract class FutureBase<T> implements FutureInternal<T> {
+
+  protected final ContextInternal context;
+
+  /**
+   * Create a future that hasn't completed yet
+   */
+  protected FutureBase() {
+    this(null);
+  }
+
+  /**
+   * Create a future that hasn't completed yet
+   */
+  FutureBase(ContextInternal context) {
+    this.context = context;
+  }
+
+  public final ContextInternal context() {
+    return context;
+  }
+
+  protected final void emitSuccess(T value, Listener<T> listener) {
+    if (context != null && !context.isRunningOnContext()) {
+      context.execute(() -> {
+        ContextInternal prev = context.beginDispatch();
+        try {
+          listener.onSuccess(value);
+        } finally {
+          context.endDispatch(prev);
+        }
+      });
+    } else {
+      listener.onSuccess(value);
+    }
+  }
+
+  protected final void emitFailure(Throwable cause, Listener<T> listener) {
+    if (context != null && !context.isRunningOnContext()) {
+      context.execute(() -> {
+        ContextInternal prev = context.beginDispatch();
+        try {
+          listener.onFailure(cause);
+        } finally {
+          context.endDispatch(prev);
+        }
+      });
+    } else {
+      listener.onFailure(cause);
+    }
+  }
+
+  @Override
+  public <U> Future<U> compose(Function<T, Future<U>> successMapper, Function<Throwable, Future<U>> failureMapper) {
+    Objects.requireNonNull(successMapper, "No null success mapper accepted");
+    Objects.requireNonNull(failureMapper, "No null failure mapper accepted");
+    Composition<T, U> operation = new Composition<>(context, successMapper, failureMapper);
+    addListener(operation);
+    return operation;
+  }
+
+  @Override
+  public <U> Future<U> transform(Function<AsyncResult<T>, Future<U>> mapper) {
+    Objects.requireNonNull(mapper, "No null mapper accepted");
+    Transformation<T, U> operation = new Transformation<>(context, this, mapper);
+    addListener(operation);
+    return operation;
+  }
+
+  @Override
+  public <U> Future<T> eventually(Function<Void, Future<U>> mapper) {
+    Objects.requireNonNull(mapper, "No null mapper accepted");
+    Eventually<T, U> operation = new Eventually<>(context, mapper);
+    addListener(operation);
+    return operation;
+  }
+
+  @Override
+  public <U> Future<U> map(Function<T, U> mapper) {
+    Objects.requireNonNull(mapper, "No null mapper accepted");
+    Mapping<T, U> operation = new Mapping<>(context, mapper);
+    addListener(operation);
+    return operation;
+  }
+
+  @Override
+  public <V> Future<V> map(V value) {
+    FixedMapping<T, V> transformation = new FixedMapping<>(context, value);
+    addListener(transformation);
+    return transformation;
+  }
+
+  @Override
+  public Future<T> otherwise(Function<Throwable, T> mapper) {
+    Objects.requireNonNull(mapper, "No null mapper accepted");
+    Otherwise<T> transformation = new Otherwise<>(context, mapper);
+    addListener(transformation);
+    return transformation;
+  }
+
+  @Override
+  public Future<T> otherwise(T value) {
+    FixedOtherwise<T> operation = new FixedOtherwise<>(context, value);
+    addListener(operation);
+    return operation;
+  }
+}

src/main/java/org/xbib/event/async/impl/future/FutureImpl.java

@@ -0,0 +1,268 @@
+package org.xbib.event.async.impl.future;
+
+import org.xbib.event.async.AsyncResult;
+import org.xbib.event.async.Future;
+import org.xbib.event.async.Handler;
+import org.xbib.event.async.NoStackTraceThrowable;
+import org.xbib.event.async.impl.ContextInternal;
+
+import java.util.ArrayList;
+import java.util.Objects;
+
+/**
+ * Future implementation.
+ */
+class FutureImpl<T> extends FutureBase<T> {
+
+  private static final Object NULL_VALUE = new Object();
+
+  private Object value;
+  private Listener<T> listener;
+
+  /**
+   * Create a future that hasn't completed yet
+   */
+  FutureImpl() {
+    super();
+  }
+
+  /**
+   * Create a future that hasn't completed yet
+   */
+  FutureImpl(ContextInternal context) {
+    super(context);
+  }
+
+  /**
+   * The result of the operation. This will be null if the operation failed.
+   */
+  public synchronized T result() {
+    return value instanceof CauseHolder ? null : value == NULL_VALUE ? null : (T) value;
+  }
+
+  /**
+   * An exception describing failure. This will be null if the operation succeeded.
+   */
+  public synchronized Throwable cause() {
+    return value instanceof CauseHolder ? ((CauseHolder)value).cause : null;
+  }
+
+  /**
+   * Did it succeed?
+   */
+  public synchronized boolean succeeded() {
+    return value != null && !(value instanceof CauseHolder);
+  }
+
+  /**
+   * Did it fail?
+   */
+  public synchronized boolean failed() {
+    return value instanceof CauseHolder;
+  }
+
+  /**
+   * Has it completed?
+   */
+  public synchronized boolean isComplete() {
+    return value != null;
+  }
+
+  @Override
+  public Future<T> onSuccess(Handler<T> handler) {
+    Objects.requireNonNull(handler, "No null handler accepted");
+    addListener(new Listener<T>() {
+      @Override
+      public void onSuccess(T value) {
+        try {
+          handler.handle(value);
+        } catch (Throwable t) {
+          if (context != null) {
+            context.reportException(t);
+          } else {
+            throw t;
+          }
+        }
+      }
+      @Override
+      public void onFailure(Throwable failure) {
+      }
+    });
+    return this;
+  }
+
+  @Override
+  public Future<T> onFailure(Handler<Throwable> handler) {
+    Objects.requireNonNull(handler, "No null handler accepted");
+    addListener(new Listener<T>() {
+      @Override
+      public void onSuccess(T value) {
+      }
+      @Override
+      public void onFailure(Throwable failure) {
+        try {
+          handler.handle(failure);
+        } catch (Throwable t) {
+          if (context != null) {
+            context.reportException(t);
+          } else {
+            throw t;
+          }
+        }
+      }
+    });
+    return this;
+  }
+
+  @Override
+  public Future<T> onComplete(Handler<AsyncResult<T>> handler) {
+    Objects.requireNonNull(handler, "No null handler accepted");
+    Listener<T> listener;
+    if (handler instanceof Listener) {
+      listener = (Listener<T>) handler;
+    } else {
+      listener = new Listener<T>() {
+        @Override
+        public void onSuccess(T value) {
+          try {
+            handler.handle(FutureImpl.this);
+          } catch (Throwable t) {
+            if (context != null) {
+              context.reportException(t);
+            } else {
+              throw t;
+            }
+          }
+        }
+        @Override
+        public void onFailure(Throwable failure) {
+          try {
+            handler.handle(FutureImpl.this);
+          } catch (Throwable t) {
+            if (context != null) {
+              context.reportException(t);
+            } else {
+              throw t;
+            }
+          }
+        }
+      };
+    }
+    addListener(listener);
+    return this;
+  }
+
+  @Override
+  public void addListener(Listener<T> listener) {
+    Object v;
+    synchronized (this) {
+      v = value;
+      if (v == null) {
+        if (this.listener == null) {
+          this.listener = listener;
+        } else {
+          ListenerArray<T> listeners;
+          if (this.listener instanceof FutureImpl.ListenerArray) {
+            listeners = (ListenerArray<T>) this.listener;
+          } else {
+            listeners = new ListenerArray<>();
+            listeners.add(this.listener);
+            this.listener = listeners;
+          }
+          listeners.add(listener);
+        }
+        return;
+      }
+    }
+    if (v instanceof CauseHolder) {
+      emitFailure(((CauseHolder)v).cause, listener);
+    } else {
+      if (v == NULL_VALUE) {
+        v = null;
+      }
+      emitSuccess((T) v, listener);
+    }
+  }
+
+  public boolean tryComplete(T result) {
+    Listener<T> l;
+    synchronized (this) {
+      if (value != null) {
+        return false;
+      }
+      value = result == null ? NULL_VALUE : result;
+      l = listener;
+      listener = null;
+    }
+    if (l != null) {
+      emitSuccess(result, l);
+    }
+    return true;
+  }
+
+  public boolean tryFail(Throwable cause) {
+    if (cause == null) {
+      cause = new NoStackTraceThrowable(null);
+    }
+    Listener<T> l;
+    synchronized (this) {
+      if (value != null) {
+        return false;
+      }
+      value = new CauseHolder(cause);
+      l = listener;
+      listener = null;
+    }
+    if (l != null) {
+      emitFailure(cause, l);
+    }
+    return true;
+  }
+
+  @Override
+  public String toString() {
+    synchronized (this) {
+      if (value instanceof CauseHolder) {
+        return "Future{cause=" + ((CauseHolder)value).cause.getMessage() + "}";
+      }
+      if (value != null) {
+        if (value == NULL_VALUE) {
+          return "Future{result=null}";
+        }
+        StringBuilder sb = new StringBuilder("Future{result=");
+        formatValue(value, sb);
+        sb.append("}");
+        return sb.toString();
+      }
+      return "Future{unresolved}";
+    }
+  }
+
+  protected void formatValue(Object value, StringBuilder sb) {
+    sb.append(value);
+  }
+
+  private static class ListenerArray<T> extends ArrayList<Listener<T>> implements Listener<T> {
+    @Override
+    public void onSuccess(T value) {
+      for (Listener<T> handler : this) {
+        handler.onSuccess(value);
+      }
+    }
+    @Override
+    public void onFailure(Throwable failure) {
+      for (Listener<T> handler : this) {
+        handler.onFailure(failure);
+      }
+    }
+  }
+
+  private static class CauseHolder {
+
+    private final Throwable cause;
+
+    CauseHolder(Throwable cause) {
+      this.cause = cause;
+    }
+  }
+}

src/main/java/org/xbib/event/async/impl/future/FutureInternal.java

@@ -0,0 +1,23 @@
+package org.xbib.event.async.impl.future;
+
+import org.xbib.event.async.Future;
+import org.xbib.event.async.impl.ContextInternal;
+
+/**
+ * Expose some of the future internal stuff.
+ */
+public interface FutureInternal<T> extends Future<T> {
+
+  /**
+   * @return the context associated with this promise or {@code null} when there is none
+   */
+  ContextInternal context();
+
+  /**
+   * Add a listener to the future result.
+   *
+   * @param listener the listener
+   */
+  void addListener(Listener<T> listener);
+
+}

src/main/java/org/xbib/event/async/impl/future/Listener.java

@@ -0,0 +1,21 @@
+package org.xbib.event.async.impl.future;
+
+/**
+ * Internal listener that signals success or failure when a future completes.
+ */
+public interface Listener<T> {
+
+  /**
+   * Signal the success.
+   *
+   * @param value the value
+   */
+  void onSuccess(T value);
+
+  /**
+   * Signal the failure
+   *
+   * @param failure the failure
+   */
+  void onFailure(Throwable failure);
+}

src/main/java/org/xbib/event/async/impl/future/Mapping.java

@@ -0,0 +1,35 @@
+package org.xbib.event.async.impl.future;
+
+import org.xbib.event.async.impl.ContextInternal;
+
+import java.util.function.Function;
+
+/**
+ * Function map transformation.
+ */
+class Mapping<T, U> extends Operation<U> implements Listener<T> {
+
+  private final Function<T, U> successMapper;
+
+  Mapping(ContextInternal context, Function<T, U> successMapper) {
+    super(context);
+    this.successMapper = successMapper;
+  }
+
+  @Override
+  public void onSuccess(T value) {
+    U result;
+    try {
+      result = successMapper.apply(value);
+    } catch (Throwable e) {
+      tryFail(e);
+      return;
+    }
+    tryComplete(result);
+  }
+
+  @Override
+  public void onFailure(Throwable failure) {
+    tryFail(failure);
+  }
+}

src/main/java/org/xbib/event/async/impl/future/Operation.java

@@ -0,0 +1,13 @@
+package org.xbib.event.async.impl.future;
+
+import org.xbib.event.async.impl.ContextInternal;
+
+/**
+ * Base class for transforming the completion of a future.
+ */
+abstract class Operation<T> extends FutureImpl<T> {
+
+  protected Operation(ContextInternal context) {
+    super(context);
+  }
+}

src/main/java/org/xbib/event/async/impl/future/Otherwise.java

@@ -0,0 +1,32 @@
+package org.xbib.event.async.impl.future;
+
+import org.xbib.event.async.impl.ContextInternal;
+
+import java.util.function.Function;
+
+class Otherwise<T> extends Operation<T> implements Listener<T> {
+
+  private final Function<Throwable, T> mapper;
+
+  Otherwise(ContextInternal context, Function<Throwable, T> mapper) {
+    super(context);
+    this.mapper = mapper;
+  }
+
+  @Override
+  public void onSuccess(T value) {
+    tryComplete(value);
+  }
+
+  @Override
+  public void onFailure(Throwable failure) {
+    T result;
+    try {
+      result = mapper.apply(failure);
+    } catch (Throwable e) {
+      tryFail(e);
+      return;
+    }
+    tryComplete(result);
+  }
+}

src/main/java/org/xbib/event/async/impl/future/PromiseImpl.java

@@ -0,0 +1,57 @@
+package org.xbib.event.async.impl.future;
+
+import org.xbib.event.Future;
+import org.xbib.event.async.AsyncResult;
+import org.xbib.event.async.impl.ContextInternal;
+
+/**
+ * Promise implementation.
+ */
+public final class PromiseImpl<T> extends FutureImpl<T> implements PromiseInternal<T>, Listener<T> {
+
+  /**
+   * Create a promise that hasn't completed yet
+   */
+  public PromiseImpl() {
+    super();
+  }
+
+  /**
+   * Create a promise that hasn't completed yet
+   */
+  public PromiseImpl(ContextInternal context) {
+    super(context);
+  }
+
+  public void handle(AsyncResult<T> ar) {
+    if (ar.succeeded()) {
+      onSuccess(ar.result());
+    } else {
+      onFailure(ar.cause());
+    }
+  }
+
+  @Override
+  public void onSuccess(T value) {
+    tryComplete(value);
+  }
+
+  @Override
+  public void onFailure(Throwable failure) {
+    tryFail(failure);
+  }
+
+  @Override
+  public org.xbib.event.async.Future<T> future() {
+    return this;
+  }
+
+  @Override
+  public void operationComplete(Future<T> future) {
+    if (future.isSuccess()) {
+      complete(future.getNow());
+    } else {
+      fail(future.cause());
+    }
+  }
+}

src/main/java/org/xbib/event/async/impl/future/PromiseInternal.java

@@ -0,0 +1,14 @@
+package org.xbib.event.async.impl.future;
+
+import org.xbib.event.FutureListener;
+import org.xbib.event.async.Promise;
+import org.xbib.event.async.impl.ContextInternal;
+
+public interface PromiseInternal<T> extends Promise<T>, FutureListener<T>, FutureInternal<T> {
+
+  /**
+   * @return the context associated with this promise or {@code null} when there is none
+   */
+  ContextInternal context();
+
+}

src/main/java/org/xbib/event/async/impl/future/SucceededFuture.java

@@ -0,0 +1,118 @@
+package org.xbib.event.async.impl.future;
+
+import org.xbib.event.async.AsyncResult;
+import org.xbib.event.async.Future;
+import org.xbib.event.async.Handler;
+import org.xbib.event.async.impl.ContextInternal;
+
+import java.util.Objects;
+import java.util.function.Function;
+
+/**
+ * Succeeded future implementation.
+ */
+public final class SucceededFuture<T> extends FutureBase<T> {
+
+  /**
+   * Stateless instance of empty results that can be shared safely.
+   */
+  public static final SucceededFuture EMPTY = new SucceededFuture(null, null);
+
+  private final T result;
+
+  /**
+   * Create a future that has already succeeded
+   * @param result the result
+   */
+  public SucceededFuture(T result) {
+    this(null, result);
+  }
+
+  /**
+   * Create a future that has already succeeded
+   * @param context the context
+   * @param result the result
+   */
+  public SucceededFuture(ContextInternal context, T result) {
+    super(context);
+    this.result = result;
+  }
+
+  @Override
+  public boolean isComplete() {
+    return true;
+  }
+
+  @Override
+  public Future<T> onSuccess(Handler<T> handler) {
+    if (context != null) {
+      context.emit(result, handler);
+    } else {
+      handler.handle(result);
+    }
+    return this;
+  }
+
+  @Override
+  public Future<T> onFailure(Handler<Throwable> handler) {
+    return this;
+  }
+
+  @Override
+  public Future<T> onComplete(Handler<AsyncResult<T>> handler) {
+    if (handler instanceof Listener) {
+      emitSuccess(result ,(Listener<T>) handler);
+    } else if (context != null) {
+      context.emit(this, handler);
+    } else {
+      handler.handle(this);
+    }
+    return this;
+  }
+
+  @Override
+  public void addListener(Listener<T> listener) {
+    emitSuccess(result ,listener);
+  }
+
+  @Override
+  public T result() {
+    return result;
+  }
+
+  @Override
+  public Throwable cause() {
+    return null;
+  }
+
+  @Override
+  public boolean succeeded() {
+    return true;
+  }
+
+  @Override
+  public boolean failed() {
+    return false;
+  }
+
+  @Override
+  public <V> Future<V> map(V value) {
+    return new SucceededFuture<>(context, value);
+  }
+
+  @Override
+  public Future<T> otherwise(Function<Throwable, T> mapper) {
+    Objects.requireNonNull(mapper, "No null mapper accepted");
+    return this;
+  }
+
+  @Override
+  public Future<T> otherwise(T value) {
+    return this;
+  }
+
+  @Override
+  public String toString() {
+    return "Future{result=" + result + "}";
+  }
+}

src/main/java/org/xbib/event/async/impl/future/Transformation.java

@@ -0,0 +1,59 @@
+package org.xbib.event.async.impl.future;
+
+import org.xbib.event.async.AsyncResult;
+import org.xbib.event.async.Future;
+import org.xbib.event.async.impl.ContextInternal;
+
+import java.util.function.Function;
+
+/**
+ * Function compose transformation.
+ */
+class Transformation<T, U> extends Operation<U> implements Listener<T> {
+
+  private final Future<T> future;
+  private final Function<AsyncResult<T>, Future<U>> mapper;
+
+  Transformation(ContextInternal context, Future<T> future, Function<AsyncResult<T>, Future<U>> mapper) {
+    super(context);
+    this.future = future;
+    this.mapper = mapper;
+  }
+
+  @Override
+  public void onSuccess(T value) {
+    FutureInternal<U> future;
+    try {
+      future = (FutureInternal<U>) mapper.apply(this.future);
+    } catch (Throwable e) {
+      tryFail(e);
+      return;
+    }
+    future.addListener(newListener());
+  }
+
+  @Override
+  public void onFailure(Throwable failure) {
+    FutureInternal<U> future;
+    try {
+      future = (FutureInternal<U>) mapper.apply(this.future);
+    } catch (Throwable e) {
+      tryFail(e);
+      return;
+    }
+    future.addListener(newListener());
+  }
+
+  private Listener<U> newListener() {
+    return new Listener<U>() {
+      @Override
+      public void onSuccess(U value) {
+        tryComplete(value);
+      }
+      @Override
+      public void onFailure(Throwable failure) {
+        tryFail(failure);
+      }
+    };
+  }
+}

src/main/java/org/xbib/event/async/spi/AsyncServiceProvider.java

@@ -0,0 +1,17 @@
+package org.xbib.event.async.spi;
+
+import org.xbib.event.async.impl.AsyncBuilder;
+
+/**
+ * Entry point for loading Vert.x SPI implementations.
+ */
+public interface AsyncServiceProvider {
+
+  /**
+   * Let the provider initialize the Vert.x builder.
+   *
+   * @param builder the builder
+   */
+  void init(AsyncBuilder builder);
+
+}

src/main/java/org/xbib/event/async/spi/AsyncThreadFactory.java

@@ -0,0 +1,23 @@
+package org.xbib.event.async.spi;
+
+import org.xbib.event.async.impl.AsyncBuilder;
+import org.xbib.event.async.impl.AsyncThread;
+
+import java.util.concurrent.TimeUnit;
+
+public interface AsyncThreadFactory extends AsyncServiceProvider {
+
+  AsyncThreadFactory INSTANCE = new AsyncThreadFactory() {
+  };
+
+  @Override
+  default void init(AsyncBuilder builder) {
+    if (builder.threadFactory() == null) {
+      builder.threadFactory(this);
+    }
+  }
+
+  default AsyncThread newVertxThread(Runnable target, String name, boolean worker, long maxExecTime, TimeUnit maxExecTimeUnit) {
+    return new AsyncThread(target, name, worker, maxExecTime, maxExecTimeUnit);
+  }
+}

src/main/java/org/xbib/event/async/spi/ExecutorServiceFactory.java

@@ -0,0 +1,45 @@
+package org.xbib.event.async.spi;
+
+import org.xbib.event.async.impl.AsyncBuilder;
+
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ThreadFactory;
+
+/**
+ * The interface for a factory used to obtain an external
+ * {@code ExecutorService}.
+ */
+public interface ExecutorServiceFactory extends AsyncServiceProvider {
+
+  /**
+   * Default instance that delegates to {@link Executors#newFixedThreadPool(int, ThreadFactory)}
+   */
+  ExecutorServiceFactory INSTANCE = (threadFactory, concurrency, maxConcurrency) ->
+    Executors.newFixedThreadPool(maxConcurrency, threadFactory);
+
+  @Override
+  default void init(AsyncBuilder builder) {
+    if (builder.executorServiceFactory() == null) {
+      builder.executorServiceFactory(this);
+    }
+  }
+
+  /**
+   * Create an ExecutorService
+   *
+   * @param threadFactory  A {@link ThreadFactory} which must be used by the
+   *                       created {@link ExecutorService} to create threads. Null
+   *                       indicates there is no requirement to use a specific
+   *                       factory.
+   * @param concurrency    The target level of concurrency or 0 which indicates
+   *                       unspecified
+   * @param maxConcurrency A hard limit to the level of concurrency required,
+   *                       should be greater than {@code concurrency} or 0 which
+   *                       indicates unspecified.
+   *
+   * @return an {@link ExecutorService} that can be used to run tasks
+   */
+  ExecutorService createExecutor(ThreadFactory threadFactory, Integer concurrency, Integer maxConcurrency);
+
+}

src/main/java/org/xbib/event/async/streams/Pipe.java

@@ -0,0 +1,68 @@
+package org.xbib.event.async.streams;
+
+import org.xbib.event.async.Future;
+
+/**
+ * Pipe data from a {@link ReadStream} to a {@link WriteStream} and performs flow control where necessary to
+ * prevent the write stream buffer from getting overfull.
+ * <p>
+ * Instances of this class read items from a {@link ReadStream} and write them to a {@link WriteStream}. If data
+ * can be read faster than it can be written this could result in the write queue of the {@link WriteStream} growing
+ * without bound, eventually causing it to exhaust all available RAM.
+ * <p>
+ * To prevent this, after each write, instances of this class check whether the write queue of the {@link
+ * WriteStream} is full, and if so, the {@link ReadStream} is paused, and a {@code drainHandler} is set on the
+ * {@link WriteStream}.
+ * <p>
+ * When the {@link WriteStream} has processed half of its backlog, the {@code drainHandler} will be
+ * called, which results in the pump resuming the {@link ReadStream}.
+ * <p>
+ * This class can be used to pipe from any {@link ReadStream} to any {@link WriteStream}.
+ * <p>
+ */
+public interface Pipe<T> {
+
+  /**
+   * Set to {@code true} to call {@link WriteStream#end()} when the source {@code ReadStream} fails, {@code false} otherwise.
+   *
+   * @param end {@code true} to end the stream on a source {@code ReadStream} failure
+   * @return a reference to this, so the API can be used fluently
+   */
+  Pipe<T> endOnFailure(boolean end);
+
+  /**
+   * Set to {@code true} to call {@link WriteStream#end()} when the source {@code ReadStream} succeeds, {@code false} otherwise.
+   *
+   * @param end {@code true} to end the stream on a source {@code ReadStream} success
+   * @return a reference to this, so the API can be used fluently
+   */
+  Pipe<T> endOnSuccess(boolean end);
+
+  /**
+   * Set to {@code true} to call {@link WriteStream#end()} when the source {@code ReadStream} completes, {@code false} otherwise.
+   * <p>
+   * Calling this overwrites {@link #endOnFailure} and {@link #endOnSuccess}.
+   *
+   * @param end {@code true} to end the stream on a source {@code ReadStream} completion
+   * @return a reference to this, so the API can be used fluently
+   */
+  Pipe<T> endOnComplete(boolean end);
+
+  /**
+   * Start to pipe the elements to the destination {@code WriteStream}.
+   * <p>
+   * When the operation fails with a write error, the source stream is resumed.
+   *
+   * @param dst the destination write stream
+   * @return a future notified when the pipe operation completes
+   */
+  Future<Void> to(WriteStream<T> dst);
+
+  /**
+   * Close the pipe.
+   * <p>
+   * The streams handlers will be unset and the read stream resumed unless it is already ended.
+   */
+  void close();
+
+}

src/main/java/org/xbib/event/async/streams/ReadStream.java

@@ -0,0 +1,102 @@
+package org.xbib.event.async.streams;
+
+import org.xbib.event.async.Future;
+import org.xbib.event.async.Handler;
+import org.xbib.event.async.streams.impl.PipeImpl;
+
+/**
+ * Represents a stream of items that can be read from.
+ * <p>
+ * Any class that implements this interface can be used by a {@link Pipe} to pipe data from it
+ * to a {@link WriteStream}.
+ * <p>
+ * <h3>Streaming mode</h3>
+ * The stream is either in <i>flowing</i> or <i>fetch</i> mode.
+ * <ul>
+ *   <i>Initially the stream is in <i>flowing</i> mode.</i>
+ *   <li>When the stream is in <i>flowing</i> mode, elements are delivered to the {@code handler}.</li>
+ *   <li>When the stream is in <i>fetch</i> mode, only the number of requested elements will be delivered to the {@code handler}.</li>
+ * </ul>
+ * The mode can be changed with the {@link #pause()}, {@link #resume()} and {@link #fetch} methods:
+ * <ul>
+ *   <li>Calling {@link #resume()} sets the <i>flowing</i> mode</li>
+ *   <li>Calling {@link #pause()} sets the <i>fetch</i> mode and resets the demand to {@code 0}</li>
+ *   <li>Calling {@link #fetch(long)} requests a specific amount of elements and adds it to the actual demand</li>
+ * </ul>
+ *
+ */
+public interface ReadStream<T> extends StreamBase {
+
+  /**
+   * Set an exception handler on the read stream.
+   *
+   * @param handler  the exception handler
+   * @return a reference to this, so the API can be used fluently
+   */
+  ReadStream<T> exceptionHandler(Handler<Throwable> handler);
+
+  /**
+   * Set a data handler. As data is read, the handler will be called with the data.
+   *
+   * @return a reference to this, so the API can be used fluently
+   */
+  ReadStream<T> handler(Handler<T> handler);
+
+  /**
+   * Pause the {@code ReadStream}, it sets the buffer in {@code fetch} mode and clears the actual demand.
+   * <p>
+   * While it's paused, no data will be sent to the data {@code handler}.
+   *
+   * @return a reference to this, so the API can be used fluently
+   */
+  ReadStream<T> pause();
+
+  /**
+   * Resume reading, and sets the buffer in {@code flowing} mode.
+   * <p/>
+   * If the {@code ReadStream} has been paused, reading will recommence on it.
+   *
+   * @return a reference to this, so the API can be used fluently
+   */
+  ReadStream<T> resume();
+
+  /**
+   * Fetch the specified {@code amount} of elements. If the {@code ReadStream} has been paused, reading will
+   * recommence with the specified {@code amount} of items, otherwise the specified {@code amount} will
+   * be added to the current stream demand.
+   *
+   * @return a reference to this, so the API can be used fluently
+   */
+  ReadStream<T> fetch(long amount);
+
+  /**
+   * Set an end handler. Once the stream has ended, and there is no more data to be read, this handler will be called.
+   *
+   * @return a reference to this, so the API can be used fluently
+   */
+  ReadStream<T> endHandler(Handler<Void> endHandler);
+
+  /**
+   * Pause this stream and return a {@link Pipe} to transfer the elements of this stream to a destination {@link WriteStream}.
+   * <p/>
+   * The stream will be resumed when the pipe will be wired to a {@code WriteStream}.
+   *
+   * @return a pipe
+   */
+  default Pipe<T> pipe() {
+    pause();
+    return new PipeImpl<>(this);
+  }
+
+  /**
+   * Pipe this {@code ReadStream} to the {@code WriteStream}.
+   * <p>
+   * Elements emitted by this stream will be written to the write stream until this stream ends or fails.
+   *
+   * @param dst the destination write stream
+   * @return a future notified when the write stream will be ended with the outcome
+   */
+  default Future<Void> pipeTo(WriteStream<T> dst) {
+    return new PipeImpl<>(this).to(dst);
+  }
+}

src/main/java/org/xbib/event/async/streams/StreamBase.java

@@ -0,0 +1,17 @@
+package org.xbib.event.async.streams;
+
+import org.xbib.event.async.Handler;
+
+/**
+ * Base interface for a stream.
+ */
+public interface StreamBase {
+
+  /**
+   * Set an exception handler.
+   *
+   * @param handler the handler
+   * @return a reference to this, so the API can be used fluently
+   */
+  StreamBase exceptionHandler(Handler<Throwable> handler);
+}

src/main/java/org/xbib/event/async/streams/WriteStream.java

@@ -0,0 +1,95 @@
+package org.xbib.event.async.streams;
+
+import org.xbib.event.async.Future;
+import org.xbib.event.async.Handler;
+
+/**
+ *
+ * Represents a stream of data that can be written to.
+ * <p>
+ * Any class that implements this interface can be used by a {@link Pipe} to pipe data from a {@code ReadStream}
+ * to it.
+ */
+public interface WriteStream<T> extends StreamBase {
+
+  /**
+   * Set an exception handler on the write stream.
+   *
+   * @param handler  the exception handler
+   * @return a reference to this, so the API can be used fluently
+   */
+  @Override
+  WriteStream<T> exceptionHandler(Handler<Throwable> handler);
+
+  /**
+   * Write some data to the stream.
+   *
+   * <p> The data is usually put on an internal write queue, and the write actually happens
+   * asynchronously. To avoid running out of memory by putting too much on the write queue,
+   * check the {@link #writeQueueFull} method before writing. This is done automatically if
+   * using a {@link Pipe}.
+   *
+   * <p> When the {@code data} is moved from the queue to the actual medium, the returned
+   * {@link Future} will be completed with the write result, e.g the future is succeeded
+   * when a server HTTP response buffer is written to the socket and failed if the remote
+   * client has closed the socket while the data was still pending for write.
+   *
+   * @param data  the data to write
+   * @return a future completed with the write result
+   */
+  Future<Void> write(T data);
+
+  /**
+   * Ends the stream.
+   * <p>
+   * Once the stream has ended, it cannot be used any more.
+   *
+   * @return a future completed with the result
+   */
+  Future<Void> end();
+
+  /**
+   * Same as {@link #end()} but writes some data to the stream before ending.
+   *
+   * @implSpec The default default implementation calls sequentially {@link #write(Object)} then {@link #end()}
+   * @apiNote Implementations might want to perform a single operation
+   * @param data the data to write
+   * @return a future completed with the result
+   */
+  default Future<Void> end(T data) {
+    return write(data).compose(v -> end());
+  }
+
+  /**
+   * Set the maximum size of the write queue to {@code maxSize}. You will still be able to write to the stream even
+   * if there is more than {@code maxSize} items in the write queue. This is used as an indicator by classes such as
+   * {@link Pipe} to provide flow control.
+   * <p/>
+   * The value is defined by the implementation of the stream.
+   *
+   * @param maxSize  the max size of the write stream
+   * @return a reference to this, so the API can be used fluently
+   */
+  WriteStream<T> setWriteQueueMaxSize(int maxSize);
+
+  /**
+   * This will return {@code true} if there are more bytes in the write queue than the value set using {@link
+   * #setWriteQueueMaxSize}
+   *
+   * @return {@code true} if write queue is full
+   */
+  boolean writeQueueFull();
+
+  /**
+   * Set a drain handler on the stream. If the write queue is full, then the handler will be called when the write
+   * queue is ready to accept buffers again. See {@link Pipe} for an example of this being used.
+   *
+   * <p> The stream implementation defines when the drain handler, for example it could be when the queue size has been
+   * reduced to {@code maxSize / 2}.
+   *
+   * @param handler the handler
+   * @return a reference to this, so the API can be used fluently
+   */
+  WriteStream<T> drainHandler(Handler<Void> handler);
+
+}

src/main/java/org/xbib/event/async/streams/impl/PipeImpl.java

@@ -0,0 +1,141 @@
+package org.xbib.event.async.streams.impl;
+
+import org.xbib.event.async.AsyncResult;
+import org.xbib.event.async.Future;
+import org.xbib.event.async.Handler;
+import org.xbib.event.async.Promise;
+import org.xbib.event.async.EventException;
+import org.xbib.event.async.streams.Pipe;
+import org.xbib.event.async.streams.ReadStream;
+import org.xbib.event.async.streams.WriteStream;
+
+public class PipeImpl<T> implements Pipe<T> {
+
+  private final Promise<Void> result;
+  private final ReadStream<T> src;
+  private boolean endOnSuccess = true;
+  private boolean endOnFailure = true;
+  private WriteStream<T> dst;
+
+  public PipeImpl(ReadStream<T> src) {
+    this.src = src;
+    this.result = Promise.promise();
+
+    // Set handlers now
+    src.endHandler(result::tryComplete);
+    src.exceptionHandler(result::tryFail);
+  }
+
+  @Override
+  public synchronized Pipe<T> endOnFailure(boolean end) {
+    endOnFailure = end;
+    return this;
+  }
+
+  @Override
+  public synchronized Pipe<T> endOnSuccess(boolean end) {
+    endOnSuccess = end;
+    return this;
+  }
+
+  @Override
+  public synchronized Pipe<T> endOnComplete(boolean end) {
+    endOnSuccess = end;
+    endOnFailure = end;
+    return this;
+  }
+
+  private void handleWriteResult(AsyncResult<Void> ack) {
+    if (ack.failed()) {
+      result.tryFail(new WriteException(ack.cause()));
+    }
+  }
+
+  @Override
+  public Future<Void> to(WriteStream<T> ws) {
+    Promise<Void> promise = Promise.promise();
+    if (ws == null) {
+      throw new NullPointerException();
+    }
+    synchronized (PipeImpl.this) {
+      if (dst != null) {
+        throw new IllegalStateException();
+      }
+      dst = ws;
+    }
+    Handler<Void> drainHandler = v -> src.resume();
+    src.handler(item -> {
+      ws.write(item).onComplete(this::handleWriteResult);
+      if (ws.writeQueueFull()) {
+        src.pause();
+        ws.drainHandler(drainHandler);
+      }
+    });
+    src.resume();
+    result.future().onComplete(ar -> {
+      try {
+        src.handler(null);
+      } catch (Exception ignore) {
+      }
+      try {
+        src.exceptionHandler(null);
+      } catch (Exception ignore) {
+      }
+      try {
+        src.endHandler(null);
+      } catch (Exception ignore) {
+      }
+      if (ar.succeeded()) {
+        handleSuccess(promise);
+      } else {
+        Throwable err = ar.cause();
+        if (err instanceof WriteException) {
+          src.resume();
+          err = err.getCause();
+        }
+        handleFailure(err, promise);
+      }
+    });
+    return promise.future();
+  }
+
+  private void handleSuccess(Promise<Void> promise) {
+    if (endOnSuccess) {
+      dst.end().onComplete(promise);
+    } else {
+      promise.complete();
+    }
+  }
+
+  private void handleFailure(Throwable cause, Promise<Void> completionHandler) {
+    if (endOnFailure){
+      dst
+        .end()
+        .transform(ar -> Future.<Void>failedFuture(cause))
+        .onComplete(completionHandler);
+    } else {
+      completionHandler.fail(cause);
+    }
+  }
+
+  public void close() {
+    synchronized (this) {
+      src.exceptionHandler(null);
+      src.handler(null);
+      if (dst != null) {
+        dst.drainHandler(null);
+        dst.exceptionHandler(null);
+      }
+    }
+    EventException err = new EventException("Pipe closed", true);
+    if (result.tryFail(err)) {
+      src.resume();
+    }
+  }
+
+  private static class WriteException extends EventException {
+    private WriteException(Throwable cause) {
+      super(cause, true);
+    }
+  }
+}

src/main/java/org/xbib/event/io/AbstractAsyncFileReaderLines.java

@@ -1,4 +1,4 @@
-package org.xbib.event.async;
+package org.xbib.event.io;
 
 import java.io.IOException;
 import java.nio.ByteBuffer;

src/main/java/org/xbib/event/io/AddOnComplete.java

@@ -1,4 +1,4 @@
-package org.xbib.event.async;
+package org.xbib.event.io;
 
 import org.reactivestreams.Subscriber;
 

src/main/java/org/xbib/event/io/AddOnError.java

@@ -1,4 +1,4 @@
-package org.xbib.event.async;
+package org.xbib.event.io;
 
 import org.reactivestreams.Subscriber;
 

src/main/java/org/xbib/event/io/AddOnNext.java

@@ -1,4 +1,4 @@
-package org.xbib.event.async;
+package org.xbib.event.io;
 
 import org.reactivestreams.Subscriber;
 

src/main/java/org/xbib/event/io/AddOnSubscribe.java

@@ -1,4 +1,4 @@
-package org.xbib.event.async;
+package org.xbib.event.io;
 
 import org.reactivestreams.Subscriber;
 import org.reactivestreams.Subscription;

src/main/java/org/xbib/event/io/AsyncFileQuery.java

@@ -1,4 +1,4 @@
-package org.xbib.event.async;
+package org.xbib.event.io;
 
 import org.xbib.event.yield.AsyncQuery;
 

src/main/java/org/xbib/event/io/AsyncFileReaderBytes.java

@@ -1,4 +1,4 @@
-package org.xbib.event.async;
+package org.xbib.event.io;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;

src/main/java/org/xbib/event/io/AsyncFileReaderLines.java

@@ -1,4 +1,4 @@
-package org.xbib.event.async;
+package org.xbib.event.io;
 
 import org.reactivestreams.Subscriber;
 import org.reactivestreams.Subscription;

src/main/java/org/xbib/event/io/AsyncFileWriter.java

@@ -1,4 +1,4 @@
-package org.xbib.event.async;
+package org.xbib.event.io;
 
 import java.io.IOException;
 import java.nio.ByteBuffer;

src/main/java/org/xbib/event/io/AsyncFiles.java

@@ -1,4 +1,4 @@
-package org.xbib.event.async;
+package org.xbib.event.io;
 
 import org.reactivestreams.Publisher;
 import org.xbib.event.yield.AsyncQuery;

src/main/java/org/xbib/event/io/EmptySubscriber.java

@@ -1,4 +1,4 @@
-package org.xbib.event.async;
+package org.xbib.event.io;
 
 import org.reactivestreams.Subscription;
 

src/main/java/org/xbib/event/io/SubscriberBuilder.java

@@ -1,4 +1,4 @@
-package org.xbib.event.async;
+package org.xbib.event.io;
 
 import org.reactivestreams.Subscriber;
 import org.reactivestreams.Subscription;

src/main/java/org/xbib/event/io/Subscribers.java

@@ -1,4 +1,4 @@
-package org.xbib.event.async;
+package org.xbib.event.io;
 
 import java.util.function.Consumer;
 

src/main/java/org/xbib/event/loop/AbstractEventExecutor.java

@@ -0,0 +1,181 @@
+package org.xbib.event.loop;
+
+import org.xbib.event.DefaultProgressivePromise;
+import org.xbib.event.DefaultPromise;
+import org.xbib.event.FailedFuture;
+import org.xbib.event.Future;
+import org.xbib.event.ProgressivePromise;
+import org.xbib.event.Promise;
+import org.xbib.event.PromiseTask;
+import org.xbib.event.ScheduledFuture;
+import org.xbib.event.SucceededFuture;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Iterator;
+import java.util.List;
+import java.util.concurrent.AbstractExecutorService;
+import java.util.concurrent.Callable;
+import java.util.concurrent.RunnableFuture;
+import java.util.concurrent.TimeUnit;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/**
+ * Abstract base class for {@link EventExecutor} implementations.
+ */
+public abstract class AbstractEventExecutor extends AbstractExecutorService implements EventExecutor {
+    private static final Logger logger = Logger.getLogger(AbstractEventExecutor.class.getName());
+
+    static final long DEFAULT_SHUTDOWN_QUIET_PERIOD = 2;
+    static final long DEFAULT_SHUTDOWN_TIMEOUT = 15;
+
+    private final EventExecutorGroup parent;
+    private final Collection<EventExecutor> selfCollection = Collections.<EventExecutor>singleton(this);
+
+    protected AbstractEventExecutor() {
+        this(null);
+    }
+
+    protected AbstractEventExecutor(EventExecutorGroup parent) {
+        this.parent = parent;
+    }
+
+    @Override
+    public EventExecutorGroup parent() {
+        return parent;
+    }
+
+    @Override
+    public EventExecutor next() {
+        return this;
+    }
+
+    @Override
+    public boolean inEventLoop() {
+        return inEventLoop(Thread.currentThread());
+    }
+
+    @Override
+    public Iterator<EventExecutor> iterator() {
+        return selfCollection.iterator();
+    }
+
+    @Override
+    public Future<?> shutdownGracefully() {
+        return shutdownGracefully(DEFAULT_SHUTDOWN_QUIET_PERIOD, DEFAULT_SHUTDOWN_TIMEOUT, TimeUnit.SECONDS);
+    }
+
+    /**
+     * @deprecated {@link #shutdownGracefully(long, long, TimeUnit)} or {@link #shutdownGracefully()} instead.
+     */
+    @Override
+    @Deprecated
+    public abstract void shutdown();
+
+    /**
+     * @deprecated {@link #shutdownGracefully(long, long, TimeUnit)} or {@link #shutdownGracefully()} instead.
+     */
+    @Override
+    @Deprecated
+    public List<Runnable> shutdownNow() {
+        shutdown();
+        return Collections.emptyList();
+    }
+
+    @Override
+    public <V> Promise<V> newPromise() {
+        return new DefaultPromise<V>(this);
+    }
+
+    @Override
+    public <V> ProgressivePromise<V> newProgressivePromise() {
+        return new DefaultProgressivePromise<V>(this);
+    }
+
+    @Override
+    public <V> Future<V> newSucceededFuture(V result) {
+        return new SucceededFuture<V>(this, result);
+    }
+
+    @Override
+    public <V> Future<V> newFailedFuture(Throwable cause) {
+        return new FailedFuture<V>(this, cause);
+    }
+
+    @Override
+    public Future<?> submit(Runnable task) {
+        return (Future<?>) super.submit(task);
+    }
+
+    @Override
+    public <T> Future<T> submit(Runnable task, T result) {
+        return (Future<T>) super.submit(task, result);
+    }
+
+    @Override
+    public <T> Future<T> submit(Callable<T> task) {
+        return (Future<T>) super.submit(task);
+    }
+
+    @Override
+    protected final <T> RunnableFuture<T> newTaskFor(Runnable runnable, T value) {
+        return new PromiseTask<T>(this, runnable, value);
+    }
+
+    @Override
+    protected final <T> RunnableFuture<T> newTaskFor(Callable<T> callable) {
+        return new PromiseTask<T>(this, callable);
+    }
+
+    @Override
+    public ScheduledFuture<?> schedule(Runnable command, long delay,
+                                       TimeUnit unit) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public <V> ScheduledFuture<V> schedule(Callable<V> callable, long delay, TimeUnit unit) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public ScheduledFuture<?> scheduleAtFixedRate(Runnable command, long initialDelay, long period, TimeUnit unit) {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public ScheduledFuture<?> scheduleWithFixedDelay(Runnable command, long initialDelay, long delay, TimeUnit unit) {
+        throw new UnsupportedOperationException();
+    }
+
+    /**
+     * Try to execute the given {@link Runnable} and just log if it throws a {@link Throwable}.
+     */
+    protected static void safeExecute(Runnable task) {
+        try {
+            task.run();
+        } catch (Throwable t) {
+            logger.log(Level.WARNING, "A task raised an exception. Task: " + task, t);
+        }
+    }
+
+    /**
+     * Like {@link #execute(Runnable)} but does not guarantee the task will be run until either
+     * a non-lazy task is executed or the executor is shut down.
+     *
+     * This is equivalent to submitting a {@link AbstractEventExecutor.LazyRunnable} to
+     * {@link #execute(Runnable)} but for an arbitrary {@link Runnable}.
+     *
+     * The default implementation just delegates to {@link #execute(Runnable)}.
+     */
+    public void lazyExecute(Runnable task) {
+        execute(task);
+    }
+
+    /**
+     * Marker interface for {@link Runnable} to indicate that it should be queued for execution
+     * but does not need to run immediately.
+     */
+    public interface LazyRunnable extends Runnable { }
+}

src/main/java/org/xbib/event/loop/AbstractEventExecutorGroup.java

@@ -0,0 +1,85 @@
+package org.xbib.event.loop;
+
+import org.xbib.event.Future;
+import org.xbib.event.ScheduledFuture;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+
+
+/**
+ * Abstract base class for {@link EventExecutorGroup} implementations.
+ */
+public abstract class AbstractEventExecutorGroup implements EventExecutorGroup {
+    @Override
+    public Future<?> submit(Runnable task) {
+        return next().submit(task);
+    }
+
+    @Override
+    public <T> Future<T> submit(Runnable task, T result) {
+        return next().submit(task, result);
+    }
+
+    @Override
+    public <T> Future<T> submit(Callable<T> task) {
+        return next().submit(task);
+    }
+
+    @Override
+    public ScheduledFuture<?> schedule(Runnable command, long delay, TimeUnit unit) {
+        return next().schedule(command, delay, unit);
+    }
+
+    @Override
+    public <V> ScheduledFuture<V> schedule(Callable<V> callable, long delay, TimeUnit unit) {
+        return next().schedule(callable, delay, unit);
+    }
+
+    @Override
+    public ScheduledFuture<?> scheduleAtFixedRate(Runnable command, long initialDelay, long period, TimeUnit unit) {
+        return next().scheduleAtFixedRate(command, initialDelay, period, unit);
+    }
+
+    @Override
+    public ScheduledFuture<?> scheduleWithFixedDelay(Runnable command, long initialDelay, long delay, TimeUnit unit) {
+        return next().scheduleWithFixedDelay(command, initialDelay, delay, unit);
+    }
+
+    @Override
+    public Future<?> shutdownGracefully() {
+        return shutdownGracefully(2, 15, TimeUnit.SECONDS);
+    }
+
+    @Override
+    public <T> List<java.util.concurrent.Future<T>> invokeAll(Collection<? extends Callable<T>> tasks)
+            throws InterruptedException {
+        return next().invokeAll(tasks);
+    }
+
+    @Override
+    public <T> List<java.util.concurrent.Future<T>> invokeAll(
+            Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit) throws InterruptedException {
+        return next().invokeAll(tasks, timeout, unit);
+    }
+
+    @Override
+    public <T> T invokeAny(Collection<? extends Callable<T>> tasks) throws InterruptedException, ExecutionException {
+        return next().invokeAny(tasks);
+    }
+
+    @Override
+    public <T> T invokeAny(Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit)
+            throws InterruptedException, ExecutionException, TimeoutException {
+        return next().invokeAny(tasks, timeout, unit);
+    }
+
+    @Override
+    public void execute(Runnable command) {
+        next().execute(command);
+    }
+}

src/main/java/org/xbib/event/loop/AbstractScheduledEventExecutor.java

@@ -0,0 +1,271 @@
+package org.xbib.event.loop;
+
+import org.xbib.event.ScheduledFuture;
+import org.xbib.event.ScheduledFutureTask;
+import org.xbib.event.util.DefaultPriorityQueue;
+import org.xbib.event.util.PriorityQueue;
+
+import java.util.Comparator;
+import java.util.Objects;
+import java.util.Queue;
+import java.util.concurrent.Callable;
+import java.util.concurrent.TimeUnit;
+
+import static org.xbib.event.ScheduledFutureTask.deadlineNanos;
+
+/**
+ * Abstract base class for {@link EventExecutor}s that want to support scheduling.
+ */
+public abstract class AbstractScheduledEventExecutor extends AbstractEventExecutor {
+    private static final Comparator<ScheduledFutureTask<?>> SCHEDULED_FUTURE_TASK_COMPARATOR =
+            new Comparator<ScheduledFutureTask<?>>() {
+                @Override
+                public int compare(ScheduledFutureTask<?> o1, ScheduledFutureTask<?> o2) {
+                    return o1.compareTo(o2);
+                }
+            };
+
+   static final Runnable WAKEUP_TASK = new Runnable() {
+       @Override
+       public void run() { } // Do nothing
+    };
+
+    PriorityQueue<ScheduledFutureTask<?>> scheduledTaskQueue;
+
+    long nextTaskId;
+
+    protected AbstractScheduledEventExecutor() {
+    }
+
+    protected AbstractScheduledEventExecutor(EventExecutorGroup parent) {
+        super(parent);
+    }
+
+    protected static long nanoTime() {
+        return ScheduledFutureTask.nanoTime();
+    }
+
+    /**
+     * Given an arbitrary deadline {@code deadlineNanos}, calculate the number of nano seconds from now
+     * {@code deadlineNanos} would expire.
+     * @param deadlineNanos An arbitrary deadline in nano seconds.
+     * @return the number of nano seconds from now {@code deadlineNanos} would expire.
+     */
+    protected static long deadlineToDelayNanos(long deadlineNanos) {
+        return ScheduledFutureTask.deadlineToDelayNanos(deadlineNanos);
+    }
+
+    /**
+     * The initial value used for delay and computations based upon a monatomic time source.
+     * @return initial value used for delay and computations based upon a monatomic time source.
+     */
+    protected static long initialNanoTime() {
+        return ScheduledFutureTask.initialNanoTime();
+    }
+
+    public PriorityQueue<ScheduledFutureTask<?>> scheduledTaskQueue() {
+        if (scheduledTaskQueue == null) {
+            scheduledTaskQueue = new DefaultPriorityQueue<ScheduledFutureTask<?>>(
+                    SCHEDULED_FUTURE_TASK_COMPARATOR,
+                    // Use same initial capacity as java.util.PriorityQueue
+                    11);
+        }
+        return scheduledTaskQueue;
+    }
+
+    private static boolean isNullOrEmpty(Queue<ScheduledFutureTask<?>> queue) {
+        return queue == null || queue.isEmpty();
+    }
+
+    /**
+     * Cancel all scheduled tasks.
+     *
+     * This method MUST be called only when {@link #inEventLoop()} is {@code true}.
+     */
+    protected void cancelScheduledTasks() {
+        assert inEventLoop();
+        PriorityQueue<ScheduledFutureTask<?>> scheduledTaskQueue = this.scheduledTaskQueue;
+        if (isNullOrEmpty(scheduledTaskQueue)) {
+            return;
+        }
+
+        final ScheduledFutureTask<?>[] scheduledTasks =
+                scheduledTaskQueue.toArray(new ScheduledFutureTask<?>[0]);
+
+        for (ScheduledFutureTask<?> task: scheduledTasks) {
+            task.cancelWithoutRemove(false);
+        }
+
+        scheduledTaskQueue.clearIgnoringIndexes();
+    }
+
+    /**
+     * @see #pollScheduledTask(long)
+     */
+    protected final Runnable pollScheduledTask() {
+        return pollScheduledTask(nanoTime());
+    }
+
+    /**
+     * Return the {@link Runnable} which is ready to be executed with the given {@code nanoTime}.
+     * You should use {@link #nanoTime()} to retrieve the correct {@code nanoTime}.
+     */
+    protected final Runnable pollScheduledTask(long nanoTime) {
+        assert inEventLoop();
+
+        ScheduledFutureTask<?> scheduledTask = peekScheduledTask();
+        if (scheduledTask == null || scheduledTask.deadlineNanos() - nanoTime > 0) {
+            return null;
+        }
+        scheduledTaskQueue.remove();
+        scheduledTask.setConsumed();
+        return scheduledTask;
+    }
+
+    /**
+     * Return the nanoseconds until the next scheduled task is ready to be run or {@code -1} if no task is scheduled.
+     */
+    protected final long nextScheduledTaskNano() {
+        ScheduledFutureTask<?> scheduledTask = peekScheduledTask();
+        return scheduledTask != null ? scheduledTask.delayNanos() : -1;
+    }
+
+    /**
+     * Return the deadline (in nanoseconds) when the next scheduled task is ready to be run or {@code -1}
+     * if no task is scheduled.
+     */
+    protected final long nextScheduledTaskDeadlineNanos() {
+        ScheduledFutureTask<?> scheduledTask = peekScheduledTask();
+        return scheduledTask != null ? scheduledTask.deadlineNanos() : -1;
+    }
+
+    final ScheduledFutureTask<?> peekScheduledTask() {
+        Queue<ScheduledFutureTask<?>> scheduledTaskQueue = this.scheduledTaskQueue;
+        return scheduledTaskQueue != null ? scheduledTaskQueue.peek() : null;
+    }
+
+    /**
+     * Returns {@code true} if a scheduled task is ready for processing.
+     */
+    protected final boolean hasScheduledTasks() {
+        ScheduledFutureTask<?> scheduledTask = peekScheduledTask();
+        return scheduledTask != null && scheduledTask.deadlineNanos() <= nanoTime();
+    }
+
+    @Override
+    public ScheduledFuture<?> schedule(Runnable command, long delay, TimeUnit unit) {
+        Objects.requireNonNull(command, "command");
+        Objects.requireNonNull(unit, "unit");
+        if (delay < 0) {
+            delay = 0;
+        }
+        return schedule(new ScheduledFutureTask<Void>(
+                this,
+                command,
+                deadlineNanos(unit.toNanos(delay))));
+    }
+
+    @Override
+    public <V> ScheduledFuture<V> schedule(Callable<V> callable, long delay, TimeUnit unit) {
+        Objects.requireNonNull(callable, "callable");
+        Objects.requireNonNull(unit, "unit");
+        if (delay < 0) {
+            delay = 0;
+        }
+        return schedule(new ScheduledFutureTask<V>(this, callable, deadlineNanos(unit.toNanos(delay))));
+    }
+
+    @Override
+    public ScheduledFuture<?> scheduleAtFixedRate(Runnable command, long initialDelay, long period, TimeUnit unit) {
+        Objects.requireNonNull(command, "command");
+        Objects.requireNonNull(unit, "unit");
+        if (initialDelay < 0) {
+            throw new IllegalArgumentException(
+                    String.format("initialDelay: %d (expected: >= 0)", initialDelay));
+        }
+        if (period <= 0) {
+            throw new IllegalArgumentException(
+                    String.format("period: %d (expected: > 0)", period));
+        }
+        return schedule(new ScheduledFutureTask<Void>(
+                this, command, deadlineNanos(unit.toNanos(initialDelay)), unit.toNanos(period)));
+    }
+
+    @Override
+    public ScheduledFuture<?> scheduleWithFixedDelay(Runnable command, long initialDelay, long delay, TimeUnit unit) {
+        Objects.requireNonNull(command, "command");
+        Objects.requireNonNull(unit, "unit");
+        if (initialDelay < 0) {
+            throw new IllegalArgumentException(
+                    String.format("initialDelay: %d (expected: >= 0)", initialDelay));
+        }
+        if (delay <= 0) {
+            throw new IllegalArgumentException(
+                    String.format("delay: %d (expected: > 0)", delay));
+        }
+        return schedule(new ScheduledFutureTask<Void>(
+                this, command, deadlineNanos(unit.toNanos(initialDelay)), -unit.toNanos(delay)));
+    }
+
+    public final void scheduleFromEventLoop(final ScheduledFutureTask<?> task) {
+        // nextTaskId a long and so there is no chance it will overflow back to 0
+        scheduledTaskQueue().add(task.setId(++nextTaskId));
+    }
+
+    private <V> ScheduledFuture<V> schedule(final ScheduledFutureTask<V> task) {
+        if (inEventLoop()) {
+            scheduleFromEventLoop(task);
+        } else {
+            final long deadlineNanos = task.deadlineNanos();
+            // task will add itself to scheduled task queue when run if not expired
+            if (beforeScheduledTaskSubmitted(deadlineNanos)) {
+                execute(task);
+            } else {
+                lazyExecute(task);
+                // Second hook after scheduling to facilitate race-avoidance
+                if (afterScheduledTaskSubmitted(deadlineNanos)) {
+                    execute(WAKEUP_TASK);
+                }
+            }
+        }
+
+        return task;
+    }
+
+    public final void removeScheduled(final ScheduledFutureTask<?> task) {
+        assert task.isCancelled();
+        if (inEventLoop()) {
+            scheduledTaskQueue().removeTyped(task);
+        } else {
+            // task will remove itself from scheduled task queue when it runs
+            lazyExecute(task);
+        }
+    }
+
+    /**
+     * Called from arbitrary non-{@link EventExecutor} threads prior to scheduled task submission.
+     * Returns {@code true} if the {@link EventExecutor} thread should be woken immediately to
+     * process the scheduled task (if not already awake).
+     * <p>
+     * If {@code false} is returned, {@link #afterScheduledTaskSubmitted(long)} will be called with
+     * the same value <i>after</i> the scheduled task is enqueued, providing another opportunity
+     * to wake the {@link EventExecutor} thread if required.
+     *
+     * @param deadlineNanos deadline of the to-be-scheduled task
+     *     relative to {@link AbstractScheduledEventExecutor#nanoTime()}
+     * @return {@code true} if the {@link EventExecutor} thread should be woken, {@code false} otherwise
+     */
+    protected boolean beforeScheduledTaskSubmitted(long deadlineNanos) {
+        return true;
+    }
+
+    /**
+     * See {@link #beforeScheduledTaskSubmitted(long)}. Called only after that method returns false.
+     *
+     * @param deadlineNanos relative to {@link AbstractScheduledEventExecutor#nanoTime()}
+     * @return  {@code true} if the {@link EventExecutor} thread should be woken, {@code false} otherwise
+     */
+    protected boolean afterScheduledTaskSubmitted(long deadlineNanos) {
+        return true;
+    }
+}

src/main/java/org/xbib/event/loop/BlockingOperationException.java

@@ -0,0 +1,24 @@
+package org.xbib.event.loop;
+
+/**
+ * An {@link IllegalStateException} which is raised when a user performed a blocking operation
+ * when the user is in an event loop thread.  If a blocking operation is performed in an event loop
+ * thread, the blocking operation will most likely enter a dead lock state, hence throwing this
+ * exception.
+ */
+public class BlockingOperationException extends IllegalStateException {
+
+    public BlockingOperationException() { }
+
+    public BlockingOperationException(String s) {
+        super(s);
+    }
+
+    public BlockingOperationException(Throwable cause) {
+        super(cause);
+    }
+
+    public BlockingOperationException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}

src/main/java/org/xbib/event/loop/DefaultEventExecutorChooserFactory.java

@@ -0,0 +1,58 @@
+package org.xbib.event.loop;
+
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicLong;
+
+/**
+ * Default implementation which uses simple round-robin to choose next {@link EventExecutor}.
+ */
+public final class DefaultEventExecutorChooserFactory implements EventExecutorChooserFactory {
+
+    public static final DefaultEventExecutorChooserFactory INSTANCE = new DefaultEventExecutorChooserFactory();
+
+    private DefaultEventExecutorChooserFactory() { }
+
+    @Override
+    public EventExecutorChooser newChooser(EventExecutor[] executors) {
+        if (isPowerOfTwo(executors.length)) {
+            return new PowerOfTwoEventExecutorChooser(executors);
+        } else {
+            return new GenericEventExecutorChooser(executors);
+        }
+    }
+
+    private static boolean isPowerOfTwo(int val) {
+        return (val & -val) == val;
+    }
+
+    private static final class PowerOfTwoEventExecutorChooser implements EventExecutorChooser {
+        private final AtomicInteger idx = new AtomicInteger();
+        private final EventExecutor[] executors;
+
+        PowerOfTwoEventExecutorChooser(EventExecutor[] executors) {
+            this.executors = executors;
+        }
+
+        @Override
+        public EventExecutor next() {
+            return executors[idx.getAndIncrement() & executors.length - 1];
+        }
+    }
+
+    private static final class GenericEventExecutorChooser implements EventExecutorChooser {
+        // Use a 'long' counter to avoid non-round-robin behaviour at the 32-bit overflow boundary.
+        // The 64-bit long solves this by placing the overflow so far into the future that no system
+        // will encounter this in practice.
+        private final AtomicLong idx = new AtomicLong();
+        private final EventExecutor[] executors;
+
+        GenericEventExecutorChooser(EventExecutor[] executors) {
+            this.executors = executors;
+        }
+
+        @Override
+        public EventExecutor next() {
+            return executors[(int) Math.abs(idx.getAndIncrement() % executors.length)];
+        }
+    }
+}

src/main/java/org/xbib/event/loop/EventExecutor.java

@@ -0,0 +1,63 @@
+
+package org.xbib.event.loop;
+
+import org.xbib.event.Future;
+import org.xbib.event.FutureListener;
+import org.xbib.event.ProgressivePromise;
+import org.xbib.event.Promise;
+
+/**
+ * The {@link EventExecutor} is a special {@link EventExecutorGroup} which comes
+ * with some handy methods to see if a {@link Thread} is executed in a event loop.
+ * Besides this, it also extends the {@link EventExecutorGroup} to allow for a generic
+ * way to access methods.
+ *
+ */
+public interface EventExecutor extends EventExecutorGroup {
+
+    /**
+     * Returns a reference to itself.
+     */
+    @Override
+    EventExecutor next();
+
+    /**
+     * Return the {@link EventExecutorGroup} which is the parent of this {@link EventExecutor},
+     */
+    EventExecutorGroup parent();
+
+    /**
+     * Calls {@link #inEventLoop(Thread)} with {@link Thread#currentThread()} as argument
+     */
+    boolean inEventLoop();
+
+    /**
+     * Return {@code true} if the given {@link Thread} is executed in the event loop,
+     * {@code false} otherwise.
+     */
+    boolean inEventLoop(Thread thread);
+
+    /**
+     * Return a new {@link Promise}.
+     */
+    <V> Promise<V> newPromise();
+
+    /**
+     * Create a new {@link ProgressivePromise}.
+     */
+    <V> ProgressivePromise<V> newProgressivePromise();
+
+    /**
+     * Create a new {@link Future} which is marked as succeeded already. So {@link Future#isSuccess()}
+     * will return {@code true}. All {@link FutureListener} added to it will be notified directly. Also
+     * every call of blocking methods will just return without blocking.
+     */
+    <V> Future<V> newSucceededFuture(V result);
+
+    /**
+     * Create a new {@link Future} which is marked as failed already. So {@link Future#isSuccess()}
+     * will return {@code false}. All {@link FutureListener} added to it will be notified directly. Also
+     * every call of blocking methods will just return without blocking.
+     */
+    <V> Future<V> newFailedFuture(Throwable cause);
+}

src/main/java/org/xbib/event/loop/EventExecutorChooserFactory.java

@@ -0,0 +1,23 @@
+package org.xbib.event.loop;
+
+/**
+ * Factory that creates new {@link EventExecutorChooser}s.
+ */
+public interface EventExecutorChooserFactory {
+
+    /**
+     * Returns a new {@link EventExecutorChooser}.
+     */
+    EventExecutorChooser newChooser(EventExecutor[] executors);
+
+    /**
+     * Chooses the next {@link EventExecutor} to use.
+     */
+    interface EventExecutorChooser {
+
+        /**
+         * Returns the new {@link EventExecutor} to use.
+         */
+        EventExecutor next();
+    }
+}

src/main/java/org/xbib/event/loop/EventExecutorGroup.java

@@ -0,0 +1,82 @@
+package org.xbib.event.loop;
+
+import org.xbib.event.Future;
+import org.xbib.event.ScheduledFuture;
+
+import java.util.Iterator;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * The {@link EventExecutorGroup} is responsible for providing the {@link EventExecutor}'s to use
+ * via its {@link #next()} method. Besides this, it is also responsible for handling their
+ * life-cycle and allows shutting them down in a global fashion.
+ *
+ */
+public interface EventExecutorGroup extends ScheduledExecutorService, Iterable<EventExecutor> {
+
+    /**
+     * Returns {@code true} if and only if all {@link EventExecutor}s managed by this {@link EventExecutorGroup}
+     * are being {@linkplain #shutdownGracefully() shut down gracefully} or was {@linkplain #isShutdown() shut down}.
+     */
+    boolean isShuttingDown();
+
+    /**
+     * Shortcut method for {@link #shutdownGracefully(long, long, TimeUnit)} with sensible default values.
+     *
+     * @return the {@link #terminationFuture()}
+     */
+    Future<?> shutdownGracefully();
+
+    /**
+     * Signals this executor that the caller wants the executor to be shut down.  Once this method is called,
+     * {@link #isShuttingDown()} starts to return {@code true}, and the executor prepares to shut itself down.
+     * Unlike {@link #shutdown()}, graceful shutdown ensures that no tasks are submitted for <i>'the quiet period'</i>
+     * (usually a couple seconds) before it shuts itself down.  If a task is submitted during the quiet period,
+     * it is guaranteed to be accepted and the quiet period will start over.
+     *
+     * @param quietPeriod the quiet period as described in the documentation
+     * @param timeout     the maximum amount of time to wait until the executor is {@linkplain #shutdown()}
+     *                    regardless if a task was submitted during the quiet period
+     * @param unit        the unit of {@code quietPeriod} and {@code timeout}
+     *
+     * @return the {@link #terminationFuture()}
+     */
+    Future<?> shutdownGracefully(long quietPeriod, long timeout, TimeUnit unit);
+
+    /**
+     * Returns the {@link Future} which is notified when all {@link EventExecutor}s managed by this
+     * {@link EventExecutorGroup} have been terminated.
+     */
+    Future<?> terminationFuture();
+
+    /**
+     * Returns one of the {@link EventExecutor}s managed by this {@link EventExecutorGroup}.
+     */
+    EventExecutor next();
+
+    @Override
+    Iterator<EventExecutor> iterator();
+
+    @Override
+    Future<?> submit(Runnable task);
+
+    @Override
+    <T> Future<T> submit(Runnable task, T result);
+
+    @Override
+    <T> Future<T> submit(Callable<T> task);
+
+    @Override
+    ScheduledFuture<?> schedule(Runnable command, long delay, TimeUnit unit);
+
+    @Override
+    <V> ScheduledFuture<V> schedule(Callable<V> callable, long delay, TimeUnit unit);
+
+    @Override
+    ScheduledFuture<?> scheduleAtFixedRate(Runnable command, long initialDelay, long period, TimeUnit unit);
+
+    @Override
+    ScheduledFuture<?> scheduleWithFixedDelay(Runnable command, long initialDelay, long delay, TimeUnit unit);
+}

src/main/java/org/xbib/event/loop/EventLoop.java

@@ -0,0 +1,6 @@
+
+package org.xbib.event.loop;
+
+public interface EventLoop extends OrderedEventExecutor, EventLoopGroup {
+    EventLoopGroup parent();
+}

src/main/java/org/xbib/event/loop/EventLoopException.java

@@ -0,0 +1,24 @@
+package org.xbib.event.loop;
+
+/**
+ * Special {@link RuntimeException} which will be thrown by {@link EventLoop} and {@link EventLoopGroup}
+ * implementations when an error occurs.
+ */
+public class EventLoopException extends RuntimeException {
+
+    public EventLoopException() {
+    }
+
+    public EventLoopException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    public EventLoopException(String message) {
+        super(message);
+    }
+
+    public EventLoopException(Throwable cause) {
+        super(cause);
+    }
+
+}

src/main/java/org/xbib/event/loop/EventLoopGroup.java

@@ -0,0 +1,7 @@
+package org.xbib.event.loop;
+
+public interface EventLoopGroup extends EventExecutorGroup {
+
+    EventLoop next();
+
+}

src/main/java/org/xbib/event/loop/EventLoopTaskQueueFactory.java

@@ -0,0 +1,20 @@
+package org.xbib.event.loop;
+
+import java.util.Queue;
+
+/**
+ * Factory used to create {@link Queue} instances that will be used to store tasks for an {@link EventLoop}.
+ *
+ * Generally speaking the returned {@link Queue} MUST be thread-safe and depending on the {@link EventLoop}
+ * implementation must be of type {@link java.util.concurrent.BlockingQueue}.
+ */
+public interface EventLoopTaskQueueFactory {
+
+    /**
+     * Returns a new {@link Queue} to use.
+     * @param maxCapacity the maximum amount of elements that can be stored in the {@link Queue} at a given point
+     *                    in time.
+     * @return the new queue.
+     */
+    Queue<Runnable> newTaskQueue(int maxCapacity);
+}

src/main/java/org/xbib/event/loop/GlobalEventExecutor.java

@@ -0,0 +1,265 @@
+package org.xbib.event.loop;
+
+import org.xbib.event.FailedFuture;
+import org.xbib.event.Future;
+import org.xbib.event.ScheduledFutureTask;
+import org.xbib.event.thread.DefaultThreadFactory;
+import org.xbib.event.thread.ThreadExecutorMap;
+
+import java.util.Objects;
+import java.util.Queue;
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.Executors;
+import java.util.concurrent.LinkedBlockingQueue;
+import java.util.concurrent.RejectedExecutionException;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/**
+ * Single-thread singleton {@link EventExecutor}.  It starts the thread automatically and stops it when there is no
+ * task pending in the task queue for 1 second.  Please note it is not scalable to schedule large number of tasks to
+ * this executor; use a dedicated executor.
+ */
+public final class GlobalEventExecutor extends AbstractScheduledEventExecutor implements OrderedEventExecutor {
+
+    private static final Logger logger = Logger.getLogger(GlobalEventExecutor.class.getName());
+
+    private static final long SCHEDULE_QUIET_PERIOD_INTERVAL = TimeUnit.SECONDS.toNanos(1);
+
+    public static final GlobalEventExecutor INSTANCE = new GlobalEventExecutor();
+
+    final BlockingQueue<Runnable> taskQueue = new LinkedBlockingQueue<Runnable>();
+    final ScheduledFutureTask<Void> quietPeriodTask = new ScheduledFutureTask<Void>(
+            this, Executors.<Void>callable(new Runnable() {
+        @Override
+        public void run() {
+            // NOOP
+        }
+    }, null), ScheduledFutureTask.deadlineNanos(SCHEDULE_QUIET_PERIOD_INTERVAL), -SCHEDULE_QUIET_PERIOD_INTERVAL);
+
+    // because the GlobalEventExecutor is a singleton, tasks submitted to it can come from arbitrary threads and this
+    // can trigger the creation of a thread from arbitrary thread groups; for this reason, the thread factory must not
+    // be sticky about its thread group
+    // visible for testing
+    final ThreadFactory threadFactory;
+    private final TaskRunner taskRunner = new TaskRunner();
+    private final AtomicBoolean started = new AtomicBoolean();
+    volatile Thread thread;
+
+    private final Future<?> terminationFuture = new FailedFuture<Object>(this, new UnsupportedOperationException());
+
+    private GlobalEventExecutor() {
+        scheduledTaskQueue().add(quietPeriodTask);
+        threadFactory = ThreadExecutorMap.apply(new DefaultThreadFactory(
+                DefaultThreadFactory.toPoolName(getClass()), false, Thread.NORM_PRIORITY, null), this);
+    }
+
+    /**
+     * Take the next {@link Runnable} from the task queue and so will block if no task is currently present.
+     *
+     * @return {@code null} if the executor thread has been interrupted or waken up.
+     */
+    Runnable takeTask() {
+        BlockingQueue<Runnable> taskQueue = this.taskQueue;
+        for (;;) {
+            ScheduledFutureTask<?> scheduledTask = peekScheduledTask();
+            if (scheduledTask == null) {
+                Runnable task = null;
+                try {
+                    task = taskQueue.take();
+                } catch (InterruptedException e) {
+                    // Ignore
+                }
+                return task;
+            } else {
+                long delayNanos = scheduledTask.delayNanos();
+                Runnable task = null;
+                if (delayNanos > 0) {
+                    try {
+                        task = taskQueue.poll(delayNanos, TimeUnit.NANOSECONDS);
+                    } catch (InterruptedException e) {
+                        // Waken up.
+                        return null;
+                    }
+                }
+                if (task == null) {
+                    // We need to fetch the scheduled tasks now as otherwise there may be a chance that
+                    // scheduled tasks are never executed if there is always one task in the taskQueue.
+                    // This is for example true for the read task of OIO Transport
+                    // See https://github.com/netty/netty/issues/1614
+                    fetchFromScheduledTaskQueue();
+                    task = taskQueue.poll();
+                }
+
+                if (task != null) {
+                    return task;
+                }
+            }
+        }
+    }
+
+    private void fetchFromScheduledTaskQueue() {
+        long nanoTime = AbstractScheduledEventExecutor.nanoTime();
+        Runnable scheduledTask = pollScheduledTask(nanoTime);
+        while (scheduledTask != null) {
+            taskQueue.add(scheduledTask);
+            scheduledTask = pollScheduledTask(nanoTime);
+        }
+    }
+
+    /**
+     * Return the number of tasks that are pending for processing.
+     */
+    public int pendingTasks() {
+        return taskQueue.size();
+    }
+
+    /**
+     * Add a task to the task queue, or throws a {@link RejectedExecutionException} if this instance was shutdown
+     * before.
+     */
+    private void addTask(Runnable task) {
+        taskQueue.add(Objects.requireNonNull(task, "task"));
+    }
+
+    @Override
+    public boolean inEventLoop(Thread thread) {
+        return thread == this.thread;
+    }
+
+    @Override
+    public Future<?> shutdownGracefully(long quietPeriod, long timeout, TimeUnit unit) {
+        return terminationFuture();
+    }
+
+    @Override
+    public Future<?> terminationFuture() {
+        return terminationFuture;
+    }
+
+    @Override
+    @Deprecated
+    public void shutdown() {
+        throw new UnsupportedOperationException();
+    }
+
+    @Override
+    public boolean isShuttingDown() {
+        return false;
+    }
+
+    @Override
+    public boolean isShutdown() {
+        return false;
+    }
+
+    @Override
+    public boolean isTerminated() {
+        return false;
+    }
+
+    @Override
+    public boolean awaitTermination(long timeout, TimeUnit unit) {
+        return false;
+    }
+
+    /**
+     * Waits until the worker thread of this executor has no tasks left in its task queue and terminates itself.
+     * Because a new worker thread will be started again when a new task is submitted, this operation is only useful
+     * when you want to ensure that the worker thread is terminated <strong>after</strong> your application is shut
+     * down and there's no chance of submitting a new task afterwards.
+     *
+     * @return {@code true} if and only if the worker thread has been terminated
+     */
+    public boolean awaitInactivity(long timeout, TimeUnit unit) throws InterruptedException {
+        Objects.requireNonNull(unit, "unit");
+
+        final Thread thread = this.thread;
+        if (thread == null) {
+            throw new IllegalStateException("thread was not started");
+        }
+        thread.join(unit.toMillis(timeout));
+        return !thread.isAlive();
+    }
+
+    @Override
+    public void execute(Runnable task) {
+        addTask(Objects.requireNonNull(task, "task"));
+        if (!inEventLoop()) {
+            startThread();
+        }
+    }
+
+    private void startThread() {
+        if (started.compareAndSet(false, true)) {
+            final Thread t = threadFactory.newThread(taskRunner);
+            // Set to null to ensure we not create classloader leaks by holds a strong reference to the inherited
+            // classloader.
+            // See:
+            // - https://github.com/netty/netty/issues/7290
+            // - https://bugs.openjdk.java.net/browse/JDK-7008595
+            t.setContextClassLoader(null);
+
+            // Set the thread before starting it as otherwise inEventLoop() may return false and so produce
+            // an assert error.
+            // See https://github.com/netty/netty/issues/4357
+            thread = t;
+            t.start();
+        }
+    }
+
+    final class TaskRunner implements Runnable {
+        @Override
+        public void run() {
+            for (;;) {
+                Runnable task = takeTask();
+                if (task != null) {
+                    try {
+                        task.run();
+                    } catch (Throwable t) {
+                        logger.log(Level.WARNING, "Unexpected exception from the global event executor: ", t);
+                    }
+
+                    if (task != quietPeriodTask) {
+                        continue;
+                    }
+                }
+
+                Queue<ScheduledFutureTask<?>> scheduledTaskQueue = GlobalEventExecutor.this.scheduledTaskQueue;
+                // Terminate if there is no task in the queue (except the noop task).
+                if (taskQueue.isEmpty() && (scheduledTaskQueue == null || scheduledTaskQueue.size() == 1)) {
+                    // Mark the current thread as stopped.
+                    // The following CAS must always success and must be uncontended,
+                    // because only one thread should be running at the same time.
+                    boolean stopped = started.compareAndSet(true, false);
+                    assert stopped;
+
+                    // Check if there are pending entries added by execute() or schedule*() while we do CAS above.
+                    // Do not check scheduledTaskQueue because it is not thread-safe and can only be mutated from a
+                    // TaskRunner actively running tasks.
+                    if (taskQueue.isEmpty()) {
+                        // A) No new task was added and thus there's nothing to handle
+                        //    -> safe to terminate because there's nothing left to do
+                        // B) A new thread started and handled all the new tasks.
+                        //    -> safe to terminate the new thread will take care the rest
+                        break;
+                    }
+
+                    // There are pending tasks added again.
+                    if (!started.compareAndSet(false, true)) {
+                        // startThread() started a new thread and set 'started' to true.
+                        // -> terminate this thread so that the new thread reads from taskQueue exclusively.
+                        break;
+                    }
+
+                    // New tasks were added, but this worker was faster to set 'started' to true.
+                    // i.e. a new worker thread was not started by startThread().
+                    // -> keep this thread alive to handle the newly added entries.
+                }
+            }
+        }
+    }
+}

src/main/java/org/xbib/event/loop/MultithreadEventExecutorGroup.java

@@ -0,0 +1,220 @@
+package org.xbib.event.loop;
+
+import org.xbib.event.DefaultPromise;
+import org.xbib.event.Future;
+import org.xbib.event.FutureListener;
+import org.xbib.event.Promise;
+import org.xbib.event.thread.DefaultThreadFactory;
+import org.xbib.event.thread.ThreadPerTaskExecutor;
+
+import java.util.Collections;
+import java.util.Iterator;
+import java.util.LinkedHashSet;
+import java.util.Set;
+import java.util.concurrent.Executor;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * Abstract base class for {@link EventExecutorGroup} implementations that handles their tasks with multiple threads at
+ * the same time.
+ */
+public abstract class MultithreadEventExecutorGroup extends AbstractEventExecutorGroup {
+
+    private final EventExecutor[] children;
+    private final Set<EventExecutor> readonlyChildren;
+    private final AtomicInteger terminatedChildren = new AtomicInteger();
+    private final Promise<?> terminationFuture = new DefaultPromise<>(GlobalEventExecutor.INSTANCE);
+    private final EventExecutorChooserFactory.EventExecutorChooser chooser;
+
+    /**
+     * Create a new instance.
+     *
+     * @param nThreads          the number of threads that will be used by this instance.
+     * @param threadFactory     the ThreadFactory to use, or {@code null} if the default should be used.
+     * @param args              arguments which will passed to each {@link #newChild(Executor, Object...)} call
+     */
+    protected MultithreadEventExecutorGroup(int nThreads, ThreadFactory threadFactory, Object... args) {
+        this(nThreads, threadFactory == null ? null : new ThreadPerTaskExecutor(threadFactory), args);
+    }
+
+    /**
+     * Create a new instance.
+     *
+     * @param nThreads          the number of threads that will be used by this instance.
+     * @param executor          the Executor to use, or {@code null} if the default should be used.
+     * @param args              arguments which will passed to each {@link #newChild(Executor, Object...)} call
+     */
+    protected MultithreadEventExecutorGroup(int nThreads, Executor executor, Object... args) {
+        this(nThreads, executor, DefaultEventExecutorChooserFactory.INSTANCE, args);
+    }
+
+    /**
+     * Create a new instance.
+     *
+     * @param nThreads          the number of threads that will be used by this instance.
+     * @param executor          the Executor to use, or {@code null} if the default should be used.
+     * @param chooserFactory    the {@link EventExecutorChooserFactory} to use.
+     * @param args              arguments which will passed to each {@link #newChild(Executor, Object...)} call
+     */
+    protected MultithreadEventExecutorGroup(int nThreads, Executor executor,
+                                            EventExecutorChooserFactory chooserFactory, Object... args) {
+        if (nThreads <= 0) {
+            throw new IllegalArgumentException("nThreads must be positive " + nThreads);
+        }
+
+        if (executor == null) {
+            executor = new ThreadPerTaskExecutor(newDefaultThreadFactory());
+        }
+
+        children = new EventExecutor[nThreads];
+
+        for (int i = 0; i < nThreads; i ++) {
+            boolean success = false;
+            try {
+                children[i] = newChild(executor, args);
+                success = true;
+            } catch (Exception e) {
+                // TODO: Think about if this is a good exception type
+                throw new IllegalStateException("failed to create a child event loop", e);
+            } finally {
+                if (!success) {
+                    for (int j = 0; j < i; j ++) {
+                        children[j].shutdownGracefully();
+                    }
+
+                    for (int j = 0; j < i; j ++) {
+                        EventExecutor e = children[j];
+                        try {
+                            while (!e.isTerminated()) {
+                                e.awaitTermination(Integer.MAX_VALUE, TimeUnit.SECONDS);
+                            }
+                        } catch (InterruptedException interrupted) {
+                            // Let the caller handle the interruption.
+                            Thread.currentThread().interrupt();
+                            break;
+                        }
+                    }
+                }
+            }
+        }
+
+        chooser = chooserFactory.newChooser(children);
+
+        final FutureListener<Object> terminationListener = new FutureListener<Object>() {
+            @Override
+            public void operationComplete(Future<Object> future) throws Exception {
+                if (terminatedChildren.incrementAndGet() == children.length) {
+                    terminationFuture.setSuccess(null);
+                }
+            }
+        };
+
+        for (EventExecutor e: children) {
+            e.terminationFuture().addListener(terminationListener);
+        }
+
+        Set<EventExecutor> childrenSet = new LinkedHashSet<EventExecutor>(children.length);
+        Collections.addAll(childrenSet, children);
+        readonlyChildren = Collections.unmodifiableSet(childrenSet);
+    }
+
+    protected ThreadFactory newDefaultThreadFactory() {
+        return new DefaultThreadFactory(getClass());
+    }
+
+    @Override
+    public EventExecutor next() {
+        return chooser.next();
+    }
+
+    @Override
+    public Iterator<EventExecutor> iterator() {
+        return readonlyChildren.iterator();
+    }
+
+    /**
+     * Return the number of {@link EventExecutor} this implementation uses. This number is the maps
+     * 1:1 to the threads it use.
+     */
+    public final int executorCount() {
+        return children.length;
+    }
+
+    /**
+     * Create a new EventExecutor which will later then accessible via the {@link #next()}  method. This method will be
+     * called for each thread that will serve this {@link MultithreadEventExecutorGroup}.
+     *
+     */
+    protected abstract EventExecutor newChild(Executor executor, Object... args) throws Exception;
+
+    @Override
+    public Future<?> shutdownGracefully(long quietPeriod, long timeout, TimeUnit unit) {
+        for (EventExecutor l: children) {
+            l.shutdownGracefully(quietPeriod, timeout, unit);
+        }
+        return terminationFuture();
+    }
+
+    @Override
+    public Future<?> terminationFuture() {
+        return terminationFuture;
+    }
+
+    @Override
+    @Deprecated
+    public void shutdown() {
+        for (EventExecutor l: children) {
+            l.shutdown();
+        }
+    }
+
+    @Override
+    public boolean isShuttingDown() {
+        for (EventExecutor l: children) {
+            if (!l.isShuttingDown()) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    @Override
+    public boolean isShutdown() {
+        for (EventExecutor l: children) {
+            if (!l.isShutdown()) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    @Override
+    public boolean isTerminated() {
+        for (EventExecutor l: children) {
+            if (!l.isTerminated()) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    @Override
+    public boolean awaitTermination(long timeout, TimeUnit unit)
+            throws InterruptedException {
+        long deadline = System.nanoTime() + unit.toNanos(timeout);
+        loop: for (EventExecutor l: children) {
+            for (;;) {
+                long timeLeft = deadline - System.nanoTime();
+                if (timeLeft <= 0) {
+                    break loop;
+                }
+                if (l.awaitTermination(timeLeft, TimeUnit.NANOSECONDS)) {
+                    break;
+                }
+            }
+        }
+        return isTerminated();
+    }
+}