http://netty.io/netty-all/: Netty is an asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers and clients. (The Netty Project) 
/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */
package io.netty.channel.embedded;

import java.net.SocketAddress;
import java.nio.channels.ClosedChannelException;
import java.util.ArrayDeque;
import java.util.Queue;

import io.netty.channel.AbstractChannel;
import io.netty.channel.Channel;
import io.netty.channel.ChannelConfig;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelId;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelMetadata;
import io.netty.channel.ChannelOutboundBuffer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.ChannelPromise;
import io.netty.channel.DefaultChannelConfig;
import io.netty.channel.DefaultChannelPipeline;
import io.netty.channel.EventLoop;
import io.netty.channel.RecvByteBufAllocator;
import io.netty.util.ReferenceCountUtil;
import io.netty.util.internal.ObjectUtil;
import io.netty.util.internal.PlatformDependent;
import io.netty.util.internal.RecyclableArrayList;
import io.netty.util.internal.logging.InternalLogger;
import io.netty.util.internal.logging.InternalLoggerFactory;


Base class for Channel implementations that are used in an embedded fashion. 
/**
 * Base class for {@link Channel} implementations that are used in an embedded fashion.
 */
public class EmbeddedChannel extends AbstractChannel {

    private static final SocketAddress LOCAL_ADDRESS = new EmbeddedSocketAddress();
    private static final SocketAddress REMOTE_ADDRESS = new EmbeddedSocketAddress();

    private static final ChannelHandler[] EMPTY_HANDLERS = new ChannelHandler[0];
    private enum State { OPEN, ACTIVE, CLOSED }

    private static final InternalLogger logger = InternalLoggerFactory.getInstance(EmbeddedChannel.class);

    private static final ChannelMetadata METADATA_NO_DISCONNECT = new ChannelMetadata(false);
    private static final ChannelMetadata METADATA_DISCONNECT = new ChannelMetadata(true);

    private final EmbeddedEventLoop loop = new EmbeddedEventLoop();
    private final ChannelFutureListener recordExceptionListener = new ChannelFutureListener() {
        @Override
        public void operationComplete(ChannelFuture future) throws Exception {
            recordException(future);
        }
    };

    private final ChannelMetadata metadata;
    private final ChannelConfig config;

    private Queue<Object> inboundMessages;
    private Queue<Object> outboundMessages;
    private Throwable lastException;
    private State state;

    
Create a new instance with an EmbeddedChannelId and an empty pipeline. 
/**
     * Create a new instance with an {@link EmbeddedChannelId} and an empty pipeline.
     */
    public EmbeddedChannel() {
        this(EMPTY_HANDLERS);
    }

    
Create a new instance with the specified ID and an empty pipeline.

Params:
  • channelId – the ChannelId that will be used to identify this channel
/**
     * Create a new instance with the specified ID and an empty pipeline.
     *
     * @param channelId the {@link ChannelId} that will be used to identify this channel
     */
    public EmbeddedChannel(ChannelId channelId) {
        this(channelId, EMPTY_HANDLERS);
    }

    
Create a new instance with the pipeline initialized with the specified handlers.

Params:
/**
     * Create a new instance with the pipeline initialized with the specified handlers.
     *
     * @param handlers the {@link ChannelHandler}s which will be add in the {@link ChannelPipeline}
     */
    public EmbeddedChannel(ChannelHandler... handlers) {
        this(EmbeddedChannelId.INSTANCE, handlers);
    }

    
Create a new instance with the pipeline initialized with the specified handlers.

Params:
/**
     * Create a new instance with the pipeline initialized with the specified handlers.
     *
     * @param hasDisconnect {@code false} if this {@link Channel} will delegate {@link #disconnect()}
     *                      to {@link #close()}, {@link false} otherwise.
     * @param handlers the {@link ChannelHandler}s which will be add in the {@link ChannelPipeline}
     */
    public EmbeddedChannel(boolean hasDisconnect, ChannelHandler... handlers) {
        this(EmbeddedChannelId.INSTANCE, hasDisconnect, handlers);
    }

    
Create a new instance with the pipeline initialized with the specified handlers.

Params:
/**
     * Create a new instance with the pipeline initialized with the specified handlers.
     *
     * @param register {@code true} if this {@link Channel} is registered to the {@link EventLoop} in the
     *                 constructor. If {@code false} the user will need to call {@link #register()}.
     * @param hasDisconnect {@code false} if this {@link Channel} will delegate {@link #disconnect()}
     *                      to {@link #close()}, {@link false} otherwise.
     * @param handlers the {@link ChannelHandler}s which will be add in the {@link ChannelPipeline}
     */
    public EmbeddedChannel(boolean register, boolean hasDisconnect, ChannelHandler... handlers) {
        this(EmbeddedChannelId.INSTANCE, register, hasDisconnect, handlers);
    }

    
Create a new instance with the channel ID set to the given ID and the pipeline
initialized with the specified handlers.

Params:
/**
     * Create a new instance with the channel ID set to the given ID and the pipeline
     * initialized with the specified handlers.
     *
     * @param channelId the {@link ChannelId} that will be used to identify this channel
     * @param handlers the {@link ChannelHandler}s which will be add in the {@link ChannelPipeline}
     */
    public EmbeddedChannel(ChannelId channelId, ChannelHandler... handlers) {
        this(channelId, false, handlers);
    }

    
Create a new instance with the channel ID set to the given ID and the pipeline
initialized with the specified handlers.

Params:
/**
     * Create a new instance with the channel ID set to the given ID and the pipeline
     * initialized with the specified handlers.
     *
     * @param channelId the {@link ChannelId} that will be used to identify this channel
     * @param hasDisconnect {@code false} if this {@link Channel} will delegate {@link #disconnect()}
     *                      to {@link #close()}, {@link false} otherwise.
     * @param handlers the {@link ChannelHandler}s which will be add in the {@link ChannelPipeline}
     */
    public EmbeddedChannel(ChannelId channelId, boolean hasDisconnect, ChannelHandler... handlers) {
        this(channelId, true, hasDisconnect, handlers);
    }

    
Create a new instance with the channel ID set to the given ID and the pipeline
initialized with the specified handlers.

Params:
/**
     * Create a new instance with the channel ID set to the given ID and the pipeline
     * initialized with the specified handlers.
     *
     * @param channelId the {@link ChannelId} that will be used to identify this channel
     * @param register {@code true} if this {@link Channel} is registered to the {@link EventLoop} in the
     *                 constructor. If {@code false} the user will need to call {@link #register()}.
     * @param hasDisconnect {@code false} if this {@link Channel} will delegate {@link #disconnect()}
     *                      to {@link #close()}, {@link false} otherwise.
     * @param handlers the {@link ChannelHandler}s which will be add in the {@link ChannelPipeline}
     */
    public EmbeddedChannel(ChannelId channelId, boolean register, boolean hasDisconnect,
                           final ChannelHandler... handlers) {
        super(null, channelId);
        metadata = metadata(hasDisconnect);
        config = new DefaultChannelConfig(this);
        setup(register, handlers);
    }

    
Create a new instance with the channel ID set to the given ID and the pipeline
initialized with the specified handlers.

Params:
/**
     * Create a new instance with the channel ID set to the given ID and the pipeline
     * initialized with the specified handlers.
     *
     * @param channelId the {@link ChannelId} that will be used to identify this channel
     * @param hasDisconnect {@code false} if this {@link Channel} will delegate {@link #disconnect()}
     *                      to {@link #close()}, {@link false} otherwise.
     * @param config the {@link ChannelConfig} which will be returned by {@link #config()}.
     * @param handlers the {@link ChannelHandler}s which will be add in the {@link ChannelPipeline}
     */
    public EmbeddedChannel(ChannelId channelId, boolean hasDisconnect, final ChannelConfig config,
                           final ChannelHandler... handlers) {
        super(null, channelId);
        metadata = metadata(hasDisconnect);
        this.config = ObjectUtil.checkNotNull(config, "config");
        setup(true, handlers);
    }

    private static ChannelMetadata metadata(boolean hasDisconnect) {
        return hasDisconnect ? METADATA_DISCONNECT : METADATA_NO_DISCONNECT;
    }

    private void setup(boolean register, final ChannelHandler... handlers) {
        ObjectUtil.checkNotNull(handlers, "handlers");
        ChannelPipeline p = pipeline();
        p.addLast(new ChannelInitializer<Channel>() {
            @Override
            protected void initChannel(Channel ch) throws Exception {
                ChannelPipeline pipeline = ch.pipeline();
                for (ChannelHandler h: handlers) {
                    if (h == null) {
                        break;
                    }
                    pipeline.addLast(h);
                }
            }
        });
        if (register) {
            ChannelFuture future = loop.register(this);
            assert future.isDone();
        }
    }

    
Register this Channel on its EventLoop. 
/**
     * Register this {@code Channel} on its {@link EventLoop}.
     */
    public void register() throws Exception {
        ChannelFuture future = loop.register(this);
        assert future.isDone();
        Throwable cause = future.cause();
        if (cause != null) {
            PlatformDependent.throwException(cause);
        }
    }

    @Override
    protected final DefaultChannelPipeline newChannelPipeline() {
        return new EmbeddedChannelPipeline(this);
    }

    @Override
    public ChannelMetadata metadata() {
        return metadata;
    }

    @Override
    public ChannelConfig config() {
        return config;
    }

    @Override
    public boolean isOpen() {
        return state != State.CLOSED;
    }

    @Override
    public boolean isActive() {
        return state == State.ACTIVE;
    }

    
Returns the Queue which holds all the Objects that were received by this Channel. 
/**
     * Returns the {@link Queue} which holds all the {@link Object}s that were received by this {@link Channel}.
     */
    public Queue<Object> inboundMessages() {
        if (inboundMessages == null) {
            inboundMessages = new ArrayDeque<Object>();
        }
        return inboundMessages;
    }

    
Deprecated:use inboundMessages()
/**
     * @deprecated use {@link #inboundMessages()}
     */
    @Deprecated
    public Queue<Object> lastInboundBuffer() {
        return inboundMessages();
    }

    
Returns the Queue which holds all the Objects that were written by this Channel. 
/**
     * Returns the {@link Queue} which holds all the {@link Object}s that were written by this {@link Channel}.
     */
    public Queue<Object> outboundMessages() {
        if (outboundMessages == null) {
            outboundMessages = new ArrayDeque<Object>();
        }
        return outboundMessages;
    }

    
Deprecated:use outboundMessages()
/**
     * @deprecated use {@link #outboundMessages()}
     */
    @Deprecated
    public Queue<Object> lastOutboundBuffer() {
        return outboundMessages();
    }

    
Return received data from this Channel 
/**
     * Return received data from this {@link Channel}
     */
    @SuppressWarnings("unchecked")
    public <T> T readInbound() {
        T message = (T) poll(inboundMessages);
        if (message != null) {
            ReferenceCountUtil.touch(message, "Caller of readInbound() will handle the message from this point");
        }
        return message;
    }

    
Read data from the outbound. This may return null if nothing is readable. 
/**
     * Read data from the outbound. This may return {@code null} if nothing is readable.
     */
    @SuppressWarnings("unchecked")
    public <T> T readOutbound() {
        T message =  (T) poll(outboundMessages);
        if (message != null) {
            ReferenceCountUtil.touch(message, "Caller of readOutbound() will handle the message from this point.");
        }
        return message;
    }

    
Write messages to the inbound of this Channel. 
Params:
  • msgs – the messages to be written
Returns:true if the write operation did add something to the inbound buffer
/**
     * Write messages to the inbound of this {@link Channel}.
     *
     * @param msgs the messages to be written
     *
     * @return {@code true} if the write operation did add something to the inbound buffer
     */
    public boolean writeInbound(Object... msgs) {
        ensureOpen();
        if (msgs.length == 0) {
            return isNotEmpty(inboundMessages);
        }

        ChannelPipeline p = pipeline();
        for (Object m: msgs) {
            p.fireChannelRead(m);
        }

        flushInbound(false, voidPromise());
        return isNotEmpty(inboundMessages);
    }

    
Writes one message to the inbound of this Channel and does not flush it. This method is conceptually equivalent to AbstractChannel.write(Object). 
See Also:
/**
     * Writes one message to the inbound of this {@link Channel} and does not flush it. This
     * method is conceptually equivalent to {@link #write(Object)}.
     *
     * @see #writeOneOutbound(Object)
     */
    public ChannelFuture writeOneInbound(Object msg) {
        return writeOneInbound(msg, newPromise());
    }

    
Writes one message to the inbound of this Channel and does not flush it. This method is conceptually equivalent to AbstractChannel.write(Object, ChannelPromise). 
See Also:
/**
     * Writes one message to the inbound of this {@link Channel} and does not flush it. This
     * method is conceptually equivalent to {@link #write(Object, ChannelPromise)}.
     *
     * @see #writeOneOutbound(Object, ChannelPromise)
     */
    public ChannelFuture writeOneInbound(Object msg, ChannelPromise promise) {
        if (checkOpen(true)) {
            pipeline().fireChannelRead(msg);
        }
        return checkException(promise);
    }

    
Flushes the inbound of this Channel. This method is conceptually equivalent to AbstractChannel.flush(). 
See Also:
/**
     * Flushes the inbound of this {@link Channel}. This method is conceptually equivalent to {@link #flush()}.
     *
     * @see #flushOutbound()
     */
    public EmbeddedChannel flushInbound() {
        flushInbound(true, voidPromise());
        return this;
    }

    private ChannelFuture flushInbound(boolean recordException, ChannelPromise promise) {
      if (checkOpen(recordException)) {
          pipeline().fireChannelReadComplete();
          runPendingTasks();
      }

      return checkException(promise);
    }

    
Write messages to the outbound of this Channel. 
Params:
  • msgs –              the messages to be written
Returns:bufferReadable returns true if the write operation did add something to the outbound buffer
/**
     * Write messages to the outbound of this {@link Channel}.
     *
     * @param msgs              the messages to be written
     * @return bufferReadable   returns {@code true} if the write operation did add something to the outbound buffer
     */
    public boolean writeOutbound(Object... msgs) {
        ensureOpen();
        if (msgs.length == 0) {
            return isNotEmpty(outboundMessages);
        }

        RecyclableArrayList futures = RecyclableArrayList.newInstance(msgs.length);
        try {
            for (Object m: msgs) {
                if (m == null) {
                    break;
                }
                futures.add(write(m));
            }

            flushOutbound0();

            int size = futures.size();
            for (int i = 0; i < size; i++) {
                ChannelFuture future = (ChannelFuture) futures.get(i);
                if (future.isDone()) {
                    recordException(future);
                } else {
                    // The write may be delayed to run later by runPendingTasks()
                    future.addListener(recordExceptionListener);
                }
            }

            checkException();
            return isNotEmpty(outboundMessages);
        } finally {
            futures.recycle();
        }
    }

    
Writes one message to the outbound of this Channel and does not flush it. This method is conceptually equivalent to AbstractChannel.write(Object). 
See Also:
/**
     * Writes one message to the outbound of this {@link Channel} and does not flush it. This
     * method is conceptually equivalent to {@link #write(Object)}.
     *
     * @see #writeOneInbound(Object)
     */
    public ChannelFuture writeOneOutbound(Object msg) {
        return writeOneOutbound(msg, newPromise());
    }

    
Writes one message to the outbound of this Channel and does not flush it. This method is conceptually equivalent to AbstractChannel.write(Object, ChannelPromise). 
See Also:
/**
     * Writes one message to the outbound of this {@link Channel} and does not flush it. This
     * method is conceptually equivalent to {@link #write(Object, ChannelPromise)}.
     *
     * @see #writeOneInbound(Object, ChannelPromise)
     */
    public ChannelFuture writeOneOutbound(Object msg, ChannelPromise promise) {
        if (checkOpen(true)) {
            return write(msg, promise);
        }
        return checkException(promise);
    }

    
Flushes the outbound of this Channel. This method is conceptually equivalent to AbstractChannel.flush(). 
See Also:
/**
     * Flushes the outbound of this {@link Channel}. This method is conceptually equivalent to {@link #flush()}.
     *
     * @see #flushInbound()
     */
    public EmbeddedChannel flushOutbound() {
        if (checkOpen(true)) {
            flushOutbound0();
        }
        checkException(voidPromise());
        return this;
    }

    private void flushOutbound0() {
        // We need to call runPendingTasks first as a ChannelOutboundHandler may used eventloop.execute(...) to
        // delay the write on the next eventloop run.
        runPendingTasks();

        flush();
    }

    
Mark this Channel as finished. Any further try to write data to it will fail. 
Returns:bufferReadable returns true if any of the used buffers has something left to read
/**
     * Mark this {@link Channel} as finished. Any further try to write data to it will fail.
     *
     * @return bufferReadable returns {@code true} if any of the used buffers has something left to read
     */
    public boolean finish() {
        return finish(false);
    }

    
Mark this Channel as finished and release all pending message in the inbound and outbound buffer. Any further try to write data to it will fail. 
Returns:bufferReadable returns true if any of the used buffers has something left to read
/**
     * Mark this {@link Channel} as finished and release all pending message in the inbound and outbound buffer.
     * Any further try to write data to it will fail.
     *
     * @return bufferReadable returns {@code true} if any of the used buffers has something left to read
     */
    public boolean finishAndReleaseAll() {
        return finish(true);
    }

    
Mark this Channel as finished. Any further try to write data to it will fail. 
Params:
  • releaseAll – if true all pending message in the inbound and outbound buffer are released.
Returns:bufferReadable returns true if any of the used buffers has something left to read
/**
     * Mark this {@link Channel} as finished. Any further try to write data to it will fail.
     *
     * @param releaseAll if {@code true} all pending message in the inbound and outbound buffer are released.
     * @return bufferReadable returns {@code true} if any of the used buffers has something left to read
     */
    private boolean finish(boolean releaseAll) {
        close();
        try {
            checkException();
            return isNotEmpty(inboundMessages) || isNotEmpty(outboundMessages);
        } finally {
            if (releaseAll) {
                releaseAll(inboundMessages);
                releaseAll(outboundMessages);
            }
        }
    }

    
Release all buffered inbound messages and return true if any were in the inbound buffer, false otherwise. 
/**
     * Release all buffered inbound messages and return {@code true} if any were in the inbound buffer, {@code false}
     * otherwise.
     */
    public boolean releaseInbound() {
        return releaseAll(inboundMessages);
    }

    
Release all buffered outbound messages and return true if any were in the outbound buffer, false otherwise. 
/**
     * Release all buffered outbound messages and return {@code true} if any were in the outbound buffer, {@code false}
     * otherwise.
     */
    public boolean releaseOutbound() {
        return releaseAll(outboundMessages);
    }

    private static boolean releaseAll(Queue<Object> queue) {
        if (isNotEmpty(queue)) {
            for (;;) {
                Object msg = queue.poll();
                if (msg == null) {
                    break;
                }
                ReferenceCountUtil.release(msg);
            }
            return true;
        }
        return false;
    }

    private void finishPendingTasks(boolean cancel) {
        runPendingTasks();
        if (cancel) {
            // Cancel all scheduled tasks that are left.
            loop.cancelScheduledTasks();
        }
    }

    @Override
    public final ChannelFuture close() {
        return close(newPromise());
    }

    @Override
    public final ChannelFuture disconnect() {
        return disconnect(newPromise());
    }

    @Override
    public final ChannelFuture close(ChannelPromise promise) {
        // We need to call runPendingTasks() before calling super.close() as there may be something in the queue
        // that needs to be run before the actual close takes place.
        runPendingTasks();
        ChannelFuture future = super.close(promise);

        // Now finish everything else and cancel all scheduled tasks that were not ready set.
        finishPendingTasks(true);
        return future;
    }

    @Override
    public final ChannelFuture disconnect(ChannelPromise promise) {
        ChannelFuture future = super.disconnect(promise);
        finishPendingTasks(!metadata.hasDisconnect());
        return future;
    }

    private static boolean isNotEmpty(Queue<Object> queue) {
        return queue != null && !queue.isEmpty();
    }

    private static Object poll(Queue<Object> queue) {
        return queue != null ? queue.poll() : null;
    }

    
Run all tasks (which also includes scheduled tasks) that are pending in the EventLoop for this Channel 
/**
     * Run all tasks (which also includes scheduled tasks) that are pending in the {@link EventLoop}
     * for this {@link Channel}
     */
    public void runPendingTasks() {
        try {
            loop.runTasks();
        } catch (Exception e) {
            recordException(e);
        }

        try {
            loop.runScheduledTasks();
        } catch (Exception e) {
            recordException(e);
        }
    }

    
Run all pending scheduled tasks in the EventLoop for this Channel and return the nanoseconds when the next scheduled task is ready to run. If no other task was scheduled it will return -1. 
/**
     * Run all pending scheduled tasks in the {@link EventLoop} for this {@link Channel} and return the
     * {@code nanoseconds} when the next scheduled task is ready to run. If no other task was scheduled it will return
     * {@code -1}.
     */
    public long runScheduledPendingTasks() {
        try {
            return loop.runScheduledTasks();
        } catch (Exception e) {
            recordException(e);
            return loop.nextScheduledTask();
        }
    }

    private void recordException(ChannelFuture future) {
        if (!future.isSuccess()) {
            recordException(future.cause());
        }
    }

    private void recordException(Throwable cause) {
        if (lastException == null) {
            lastException = cause;
        } else {
            logger.warn(
                    "More than one exception was raised. " +
                            "Will report only the first one and log others.", cause);
        }
    }

    
Checks for the presence of an Exception. 
/**
     * Checks for the presence of an {@link Exception}.
     */
    private ChannelFuture checkException(ChannelPromise promise) {
      Throwable t = lastException;
      if (t != null) {
        lastException = null;

        if (promise.isVoid()) {
            PlatformDependent.throwException(t);
        }

        return promise.setFailure(t);
      }

      return promise.setSuccess();
    }

    
Check if there was any Throwable received and if so rethrow it. 
/**
     * Check if there was any {@link Throwable} received and if so rethrow it.
     */
    public void checkException() {
      checkException(voidPromise());
    }

    
Returns true if the Channel is open and records optionally an Exception if it isn't. 
/**
     * Returns {@code true} if the {@link Channel} is open and records optionally
     * an {@link Exception} if it isn't.
     */
    private boolean checkOpen(boolean recordException) {
        if (!isOpen()) {
          if (recordException) {
              recordException(new ClosedChannelException());
          }
          return false;
      }

      return true;
    }

    
Ensure the Channel is open and if not throw an exception. 
/**
     * Ensure the {@link Channel} is open and if not throw an exception.
     */
    protected final void ensureOpen() {
        if (!checkOpen(true)) {
            checkException();
        }
    }

    @Override
    protected boolean isCompatible(EventLoop loop) {
        return loop instanceof EmbeddedEventLoop;
    }

    @Override
    protected SocketAddress localAddress0() {
        return isActive()? LOCAL_ADDRESS : null;
    }

    @Override
    protected SocketAddress remoteAddress0() {
        return isActive()? REMOTE_ADDRESS : null;
    }

    @Override
    protected void doRegister() throws Exception {
        state = State.ACTIVE;
    }

    @Override
    protected void doBind(SocketAddress localAddress) throws Exception {
        // NOOP
    }

    @Override
    protected void doDisconnect() throws Exception {
        if (!metadata.hasDisconnect()) {
            doClose();
        }
    }

    @Override
    protected void doClose() throws Exception {
        state = State.CLOSED;
    }

    @Override
    protected void doBeginRead() throws Exception {
        // NOOP
    }

    @Override
    protected AbstractUnsafe newUnsafe() {
        return new EmbeddedUnsafe();
    }

    @Override
    public Unsafe unsafe() {
        return ((EmbeddedUnsafe) super.unsafe()).wrapped;
    }

    @Override
    protected void doWrite(ChannelOutboundBuffer in) throws Exception {
        for (;;) {
            Object msg = in.current();
            if (msg == null) {
                break;
            }

            ReferenceCountUtil.retain(msg);
            handleOutboundMessage(msg);
            in.remove();
        }
    }

    
Called for each outbound message.

See Also:
  • doWrite(ChannelOutboundBuffer)
/**
     * Called for each outbound message.
     *
     * @see #doWrite(ChannelOutboundBuffer)
     */
    protected void handleOutboundMessage(Object msg) {
        outboundMessages().add(msg);
    }

    
Called for each inbound message.

/**
     * Called for each inbound message.
     */
    protected void handleInboundMessage(Object msg) {
        inboundMessages().add(msg);
    }

    private final class EmbeddedUnsafe extends AbstractUnsafe {

        // Delegates to the EmbeddedUnsafe instance but ensures runPendingTasks() is called after each operation
        // that may change the state of the Channel and may schedule tasks for later execution.
        final Unsafe wrapped = new Unsafe() {
            @Override
            public RecvByteBufAllocator.Handle recvBufAllocHandle() {
                return EmbeddedUnsafe.this.recvBufAllocHandle();
            }

            @Override
            public SocketAddress localAddress() {
                return EmbeddedUnsafe.this.localAddress();
            }

            @Override
            public SocketAddress remoteAddress() {
                return EmbeddedUnsafe.this.remoteAddress();
            }

            @Override
            public void register(EventLoop eventLoop, ChannelPromise promise) {
                EmbeddedUnsafe.this.register(eventLoop, promise);
                runPendingTasks();
            }

            @Override
            public void bind(SocketAddress localAddress, ChannelPromise promise) {
                EmbeddedUnsafe.this.bind(localAddress, promise);
                runPendingTasks();
            }

            @Override
            public void connect(SocketAddress remoteAddress, SocketAddress localAddress, ChannelPromise promise) {
                EmbeddedUnsafe.this.connect(remoteAddress, localAddress, promise);
                runPendingTasks();
            }

            @Override
            public void disconnect(ChannelPromise promise) {
                EmbeddedUnsafe.this.disconnect(promise);
                runPendingTasks();
            }

            @Override
            public void close(ChannelPromise promise) {
                EmbeddedUnsafe.this.close(promise);
                runPendingTasks();
            }

            @Override
            public void closeForcibly() {
                EmbeddedUnsafe.this.closeForcibly();
                runPendingTasks();
            }

            @Override
            public void deregister(ChannelPromise promise) {
                EmbeddedUnsafe.this.deregister(promise);
                runPendingTasks();
            }

            @Override
            public void beginRead() {
                EmbeddedUnsafe.this.beginRead();
                runPendingTasks();
            }

            @Override
            public void write(Object msg, ChannelPromise promise) {
                EmbeddedUnsafe.this.write(msg, promise);
                runPendingTasks();
            }

            @Override
            public void flush() {
                EmbeddedUnsafe.this.flush();
                runPendingTasks();
            }

            @Override
            public ChannelPromise voidPromise() {
                return EmbeddedUnsafe.this.voidPromise();
            }

            @Override
            public ChannelOutboundBuffer outboundBuffer() {
                return EmbeddedUnsafe.this.outboundBuffer();
            }
        };

        @Override
        public void connect(SocketAddress remoteAddress, SocketAddress localAddress, ChannelPromise promise) {
            safeSetSuccess(promise);
        }
    }

    private final class EmbeddedChannelPipeline extends DefaultChannelPipeline {
        EmbeddedChannelPipeline(EmbeddedChannel channel) {
            super(channel);
        }

        @Override
        protected void onUnhandledInboundException(Throwable cause) {
            recordException(cause);
        }

        @Override
        protected void onUnhandledInboundMessage(Object msg) {
          handleInboundMessage(msg);
        }
    }
}