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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up with different versions on classes on the class path).

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/*
 * 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:
 *
 *   https://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.local;

import io.netty.buffer.ByteBuf;
import io.netty.channel.AbstractChannel;
import io.netty.channel.Channel;
import io.netty.channel.ChannelConfig;
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.EventLoop;
import io.netty.channel.PreferHeapByteBufAllocator;
import io.netty.channel.RecvByteBufAllocator;
import io.netty.channel.SingleThreadEventLoop;
import io.netty.util.ReferenceCountUtil;
import io.netty.util.concurrent.Future;
import io.netty.util.concurrent.SingleThreadEventExecutor;
import io.netty.util.internal.InternalThreadLocalMap;
import io.netty.util.internal.PlatformDependent;
import io.netty.util.internal.logging.InternalLogger;
import io.netty.util.internal.logging.InternalLoggerFactory;

import java.net.ConnectException;
import java.net.SocketAddress;
import java.nio.channels.AlreadyConnectedException;
import java.nio.channels.ClosedChannelException;
import java.nio.channels.ConnectionPendingException;
import java.nio.channels.NotYetConnectedException;
import java.util.Queue;
import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;

/**
 * A {@link Channel} for the local transport.
 */
public class LocalChannel extends AbstractChannel {
    private static final InternalLogger logger = InternalLoggerFactory.getInstance(LocalChannel.class);
    @SuppressWarnings({ "rawtypes" })
    private static final AtomicReferenceFieldUpdater FINISH_READ_FUTURE_UPDATER =
            AtomicReferenceFieldUpdater.newUpdater(LocalChannel.class, Future.class, "finishReadFuture");
    private static final ChannelMetadata METADATA = new ChannelMetadata(false);
    private static final int MAX_READER_STACK_DEPTH = 8;

    private enum State { OPEN, BOUND, CONNECTED, CLOSED }

    private final ChannelConfig config = new DefaultChannelConfig(this);
    // To further optimize this we could write our own SPSC queue.
    final Queue inboundBuffer = PlatformDependent.newSpscQueue();
    private final Runnable readTask = new Runnable() {
        @Override
        public void run() {
            // Ensure the inboundBuffer is not empty as readInbound() will always call fireChannelReadComplete()
            if (!inboundBuffer.isEmpty()) {
                readInbound();
            }
        }
    };

    private final Runnable shutdownHook = new Runnable() {
        @Override
        public void run() {
            unsafe().close(unsafe().voidPromise());
        }
    };

    private volatile State state;
    private volatile LocalChannel peer;
    private volatile LocalAddress localAddress;
    private volatile LocalAddress remoteAddress;
    private volatile ChannelPromise connectPromise;
    private volatile boolean readInProgress;
    private volatile boolean writeInProgress;
    private volatile Future finishReadFuture;

    public LocalChannel() {
        super(null);
        config().setAllocator(new PreferHeapByteBufAllocator(config.getAllocator()));
    }

    protected LocalChannel(LocalServerChannel parent, LocalChannel peer) {
        super(parent);
        config().setAllocator(new PreferHeapByteBufAllocator(config.getAllocator()));
        this.peer = peer;
        localAddress = parent.localAddress();
        remoteAddress = peer.localAddress();
    }

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

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

    @Override
    public LocalServerChannel parent() {
        return (LocalServerChannel) super.parent();
    }

    @Override
    public LocalAddress localAddress() {
        return (LocalAddress) super.localAddress();
    }

    @Override
    public LocalAddress remoteAddress() {
        return (LocalAddress) super.remoteAddress();
    }

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

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

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

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

    @Override
    protected SocketAddress localAddress0() {
        return localAddress;
    }

    @Override
    protected SocketAddress remoteAddress0() {
        return remoteAddress;
    }

    @Override
    protected void doRegister() throws Exception {
        // Check if both peer and parent are non-null because this channel was created by a LocalServerChannel.
        // This is needed as a peer may not be null also if a LocalChannel was connected before and
        // deregistered / registered later again.
        //
        // See https://github.com/netty/netty/issues/2400
        if (peer != null && parent() != null) {
            // Store the peer in a local variable as it may be set to null if doClose() is called.
            // See https://github.com/netty/netty/issues/2144
            final LocalChannel peer = this.peer;
            state = State.CONNECTED;

            peer.remoteAddress = parent() == null ? null : parent().localAddress();
            peer.state = State.CONNECTED;

            // Always call peer.eventLoop().execute() even if peer.eventLoop().inEventLoop() is true.
            // This ensures that if both channels are on the same event loop, the peer's channelActive
            // event is triggered *after* this channel's channelRegistered event, so that this channel's
            // pipeline is fully initialized by ChannelInitializer before any channelRead events.
            peer.eventLoop().execute(new Runnable() {
                @Override
                public void run() {
                    ChannelPromise promise = peer.connectPromise;

                    // Only trigger fireChannelActive() if the promise was not null and was not completed yet.
                    // connectPromise may be set to null if doClose() was called in the meantime.
                    if (promise != null && promise.trySuccess()) {
                        peer.pipeline().fireChannelActive();
                    }
                }
            });
        }
        ((SingleThreadEventExecutor) eventLoop()).addShutdownHook(shutdownHook);
    }

    @Override
    protected void doBind(SocketAddress localAddress) throws Exception {
        this.localAddress =
                LocalChannelRegistry.register(this, this.localAddress,
                        localAddress);
        state = State.BOUND;
    }

    @Override
    protected void doDisconnect() throws Exception {
        doClose();
    }

    @Override
    protected void doClose() throws Exception {
        final LocalChannel peer = this.peer;
        State oldState = state;
        try {
            if (oldState != State.CLOSED) {
                // Update all internal state before the closeFuture is notified.
                if (localAddress != null) {
                    if (parent() == null) {
                        LocalChannelRegistry.unregister(localAddress);
                    }
                    localAddress = null;
                }

                // State change must happen before finishPeerRead to ensure writes are released either in doWrite or
                // channelRead.
                state = State.CLOSED;

                // Preserve order of event and force a read operation now before the close operation is processed.
                if (writeInProgress && peer != null) {
                    finishPeerRead(peer);
                }

                ChannelPromise promise = connectPromise;
                if (promise != null) {
                    // Use tryFailure() instead of setFailure() to avoid the race against cancel().
                    promise.tryFailure(new ClosedChannelException());
                    connectPromise = null;
                }
            }

            if (peer != null) {
                this.peer = null;
                // Always call peer.eventLoop().execute() even if peer.eventLoop().inEventLoop() is true.
                // This ensures that if both channels are on the same event loop, the peer's channelInActive
                // event is triggered *after* this peer's channelInActive event
                EventLoop peerEventLoop = peer.eventLoop();
                final boolean peerIsActive = peer.isActive();
                try {
                    peerEventLoop.execute(new Runnable() {
                        @Override
                        public void run() {
                            peer.tryClose(peerIsActive);
                        }
                    });
                } catch (Throwable cause) {
                    logger.warn("Releasing Inbound Queues for channels {}-{} because exception occurred!",
                            this, peer, cause);
                    if (peerEventLoop.inEventLoop()) {
                        peer.releaseInboundBuffers();
                    } else {
                        // inboundBuffers is a SPSC so we may leak if the event loop is shutdown prematurely or
                        // rejects the close Runnable but give a best effort.
                        peer.close();
                    }
                    PlatformDependent.throwException(cause);
                }
            }
        } finally {
            // Release all buffers if the Channel was already registered in the past and if it was not closed before.
            if (oldState != null && oldState != State.CLOSED) {
                // We need to release all the buffers that may be put into our inbound queue since we closed the Channel
                // to ensure we not leak any memory. This is fine as it basically gives the same guarantees as TCP which
                // means even if the promise was notified before its not really guaranteed that the "remote peer" will
                // see the buffer at all.
                releaseInboundBuffers();
            }
        }
    }

    private void tryClose(boolean isActive) {
        if (isActive) {
            unsafe().close(unsafe().voidPromise());
        } else {
            releaseInboundBuffers();
        }
    }

    @Override
    protected void doDeregister() throws Exception {
        // Just remove the shutdownHook as this Channel may be closed later or registered to another EventLoop
        ((SingleThreadEventExecutor) eventLoop()).removeShutdownHook(shutdownHook);
    }

    private void readInbound() {
        RecvByteBufAllocator.Handle handle = unsafe().recvBufAllocHandle();
        handle.reset(config());
        ChannelPipeline pipeline = pipeline();
        do {
            Object received = inboundBuffer.poll();
            if (received == null) {
                break;
            }
            if (received instanceof ByteBuf && inboundBuffer.peek() instanceof ByteBuf) {
                ByteBuf msg = (ByteBuf) received;
                ByteBuf output = handle.allocate(alloc());
                if (msg.readableBytes() < output.writableBytes()) {
                    // We have an opportunity to coalesce buffers.
                    output.writeBytes(msg, msg.readerIndex(), msg.readableBytes());
                    msg.release();
                    while ((received = inboundBuffer.peek()) instanceof ByteBuf &&
                            ((ByteBuf) received).readableBytes() < output.writableBytes()) {
                        inboundBuffer.poll();
                        msg = (ByteBuf) received;
                        output.writeBytes(msg, msg.readerIndex(), msg.readableBytes());
                        msg.release();
                    }
                    handle.lastBytesRead(output.readableBytes());
                    received = output; // Send the coalesced buffer down the pipeline.
                } else {
                    // It won't be profitable to coalesce buffers this time around.
                    handle.lastBytesRead(output.capacity());
                    output.release();
                }
            }
            handle.incMessagesRead(1);
            pipeline.fireChannelRead(received);
        } while (handle.continueReading());
        handle.readComplete();
        pipeline.fireChannelReadComplete();
    }

    @Override
    protected void doBeginRead() throws Exception {
        if (readInProgress) {
            return;
        }

        Queue inboundBuffer = this.inboundBuffer;
        if (inboundBuffer.isEmpty()) {
            readInProgress = true;
            return;
        }

        final InternalThreadLocalMap threadLocals = InternalThreadLocalMap.get();
        final int stackDepth = threadLocals.localChannelReaderStackDepth();
        if (stackDepth < MAX_READER_STACK_DEPTH) {
            threadLocals.setLocalChannelReaderStackDepth(stackDepth + 1);
            try {
                readInbound();
            } finally {
                threadLocals.setLocalChannelReaderStackDepth(stackDepth);
            }
        } else {
            try {
                eventLoop().execute(readTask);
            } catch (Throwable cause) {
                logger.warn("Closing Local channels {}-{} because exception occurred!", this, peer, cause);
                close();
                peer.close();
                PlatformDependent.throwException(cause);
            }
        }
    }

    @Override
    protected void doWrite(ChannelOutboundBuffer in) throws Exception {
        switch (state) {
        case OPEN:
        case BOUND:
            throw new NotYetConnectedException();
        case CLOSED:
            throw new ClosedChannelException();
        case CONNECTED:
            break;
        }

        final LocalChannel peer = this.peer;

        writeInProgress = true;
        try {
            ClosedChannelException exception = null;
            for (;;) {
                Object msg = in.current();
                if (msg == null) {
                    break;
                }
                try {
                    // It is possible the peer could have closed while we are writing, and in this case we should
                    // simulate real socket behavior and ensure the write operation is failed.
                    if (peer.state == State.CONNECTED) {
                        peer.inboundBuffer.add(ReferenceCountUtil.retain(msg));
                        in.remove();
                    } else {
                        if (exception == null) {
                            exception = new ClosedChannelException();
                        }
                        in.remove(exception);
                    }
                } catch (Throwable cause) {
                    in.remove(cause);
                }
            }
        } finally {
            // The following situation may cause trouble:
            // 1. Write (with promise X)
            // 2. promise X is completed when in.remove() is called, and a listener on this promise calls close()
            // 3. Then the close event will be executed for the peer before the write events, when the write events
            // actually happened before the close event.
            writeInProgress = false;
        }

        finishPeerRead(peer);
    }

    private void finishPeerRead(final LocalChannel peer) {
        // If the peer is also writing, then we must schedule the event on the event loop to preserve read order.
        if (peer.eventLoop() == eventLoop() && !peer.writeInProgress) {
            finishPeerRead0(peer);
        } else {
            runFinishPeerReadTask(peer);
        }
    }

    private void runFinishPeerReadTask(final LocalChannel peer) {
        // If the peer is writing, we must wait until after reads are completed for that peer before we can read. So
        // we keep track of the task, and coordinate later that our read can't happen until the peer is done.
        final Runnable finishPeerReadTask = new Runnable() {
            @Override
            public void run() {
                finishPeerRead0(peer);
            }
        };
        try {
            if (peer.writeInProgress) {
                peer.finishReadFuture = peer.eventLoop().submit(finishPeerReadTask);
            } else {
                peer.eventLoop().execute(finishPeerReadTask);
            }
        } catch (Throwable cause) {
            logger.warn("Closing Local channels {}-{} because exception occurred!", this, peer, cause);
            close();
            peer.close();
            PlatformDependent.throwException(cause);
        }
    }

    private void releaseInboundBuffers() {
        assert eventLoop() == null || eventLoop().inEventLoop();
        readInProgress = false;
        Queue inboundBuffer = this.inboundBuffer;
        Object msg;
        while ((msg = inboundBuffer.poll()) != null) {
            ReferenceCountUtil.release(msg);
        }
    }

    private void finishPeerRead0(LocalChannel peer) {
        Future peerFinishReadFuture = peer.finishReadFuture;
        if (peerFinishReadFuture != null) {
            if (!peerFinishReadFuture.isDone()) {
                runFinishPeerReadTask(peer);
                return;
            } else {
                // Lazy unset to make sure we don't prematurely unset it while scheduling a new task.
                FINISH_READ_FUTURE_UPDATER.compareAndSet(peer, peerFinishReadFuture, null);
            }
        }
        // We should only set readInProgress to false if there is any data that was read as otherwise we may miss to
        // forward data later on.
        if (peer.readInProgress && !peer.inboundBuffer.isEmpty()) {
            peer.readInProgress = false;
            peer.readInbound();
        }
    }

    private class LocalUnsafe extends AbstractUnsafe {

        @Override
        public void connect(final SocketAddress remoteAddress,
                SocketAddress localAddress, final ChannelPromise promise) {
            if (!promise.setUncancellable() || !ensureOpen(promise)) {
                return;
            }

            if (state == State.CONNECTED) {
                Exception cause = new AlreadyConnectedException();
                safeSetFailure(promise, cause);
                pipeline().fireExceptionCaught(cause);
                return;
            }

            if (connectPromise != null) {
                throw new ConnectionPendingException();
            }

            connectPromise = promise;

            if (state != State.BOUND) {
                // Not bound yet and no localAddress specified - get one.
                if (localAddress == null) {
                    localAddress = new LocalAddress(LocalChannel.this);
                }
            }

            if (localAddress != null) {
                try {
                    doBind(localAddress);
                } catch (Throwable t) {
                    safeSetFailure(promise, t);
                    close(voidPromise());
                    return;
                }
            }

            Channel boundChannel = LocalChannelRegistry.get(remoteAddress);
            if (!(boundChannel instanceof LocalServerChannel)) {
                Exception cause = new ConnectException("connection refused: " + remoteAddress);
                safeSetFailure(promise, cause);
                close(voidPromise());
                return;
            }

            LocalServerChannel serverChannel = (LocalServerChannel) boundChannel;
            peer = serverChannel.serve(LocalChannel.this);
        }
    }
}
    

    

    

            

    

            



    
    






    
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