/*
* 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.local;
import io.netty.channel.AbstractChannel;
import io.netty.channel.Channel;
import io.netty.channel.ChannelConfig;
import io.netty.channel.ChannelException;
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.SingleThreadEventLoop;
import io.netty.util.ReferenceCountUtil;
import io.netty.util.concurrent.SingleThreadEventExecutor;
import io.netty.util.internal.InternalThreadLocalMap;
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.ArrayDeque;
import java.util.Collections;
import java.util.Queue;
/**
* A {@link Channel} for the local transport.
*/
public class LocalChannel extends AbstractChannel {
private static final ChannelMetadata METADATA = new ChannelMetadata(false);
private static final int MAX_READER_STACK_DEPTH = 8;
private final ChannelConfig config = new DefaultChannelConfig(this);
private final Queue<Object> inboundBuffer = new ArrayDeque<Object>();
private final Runnable readTask = new Runnable() {
@Override
public void run() {
ChannelPipeline pipeline = pipeline();
for (;;) {
Object m = inboundBuffer.poll();
if (m == null) {
break;
}
pipeline.fireChannelRead(m);
}
pipeline.fireChannelReadComplete();
}
};
private final Runnable shutdownHook = new Runnable() {
@Override
public void run() {
unsafe().close(unsafe().voidPromise());
}
};
private volatile int state; // 0 - open, 1 - bound, 2 - connected, 3 - closed
private volatile LocalChannel peer;
private volatile LocalAddress localAddress;
private volatile LocalAddress remoteAddress;
private volatile ChannelPromise connectPromise;
private volatile boolean readInProgress;
private volatile boolean registerInProgress;
public LocalChannel() {
super(null);
}
LocalChannel(LocalServerChannel parent, LocalChannel peer) {
super(parent);
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 < 3;
}
@Override
public boolean isActive() {
return state == 2;
}
@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.
// Because of this we also set registerInProgress to true as we check for this in doClose() and make sure
// we delay the fireChannelInactive() to be fired after the fireChannelActive() and so keep the correct
// order of events.
//
// See https://github.com/netty/netty/issues/2144
final LocalChannel peer = this.peer;
registerInProgress = true;
state = 2;
peer.remoteAddress = parent().localAddress();
peer.state = 2;
// 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() {
registerInProgress = false;
peer.pipeline().fireChannelActive();
peer.connectPromise.setSuccess();
}
});
}
((SingleThreadEventExecutor) eventLoop()).addShutdownHook(shutdownHook);
}
@Override
protected void doBind(SocketAddress localAddress) throws Exception {
this.localAddress =
LocalChannelRegistry.register(this, this.localAddress,
localAddress);
state = 1;
}
@Override
protected void doDisconnect() throws Exception {
doClose();
}
@Override
protected void doClose() throws Exception {
if (state <= 2) {
// Update all internal state before the closeFuture is notified.
if (localAddress != null) {
if (parent() == null) {
LocalChannelRegistry.unregister(localAddress);
}
localAddress = null;
}
state = 3;
}
final LocalChannel peer = this.peer;
if (peer != null && peer.isActive()) {
// Need to execute the close in the correct EventLoop
// See https://github.com/netty/netty/issues/1777
EventLoop eventLoop = peer.eventLoop();
// Also check if the registration was not done yet. In this case we submit the close to the EventLoop
// to make sure it is run after the registration completes.
//
// See https://github.com/netty/netty/issues/2144
if (eventLoop.inEventLoop() && !registerInProgress) {
peer.unsafe().close(unsafe().voidPromise());
} else {
peer.eventLoop().execute(new Runnable() {
@Override
public void run() {
peer.unsafe().close(unsafe().voidPromise());
}
});
}
this.peer = null;
}
}
@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);
}
@Override
protected void doBeginRead() throws Exception {
if (readInProgress) {
return;
}
ChannelPipeline pipeline = pipeline();
Queue<Object> inboundBuffer = this.inboundBuffer;
if (inboundBuffer.isEmpty()) {
readInProgress = true;
return;
}
final InternalThreadLocalMap threadLocals = InternalThreadLocalMap.get();
final Integer stackDepth = threadLocals.localChannelReaderStackDepth();
if (stackDepth < MAX_READER_STACK_DEPTH) {
threadLocals.setLocalChannelReaderStackDepth(stackDepth + 1);
try {
for (;;) {
Object received = inboundBuffer.poll();
if (received == null) {
break;
}
pipeline.fireChannelRead(received);
}
pipeline.fireChannelReadComplete();
} finally {
threadLocals.setLocalChannelReaderStackDepth(stackDepth);
}
} else {
eventLoop().execute(readTask);
}
}
@Override
protected void doWrite(ChannelOutboundBuffer in) throws Exception {
if (state < 2) {
throw new NotYetConnectedException();
}
if (state > 2) {
throw new ClosedChannelException();
}
final LocalChannel peer = this.peer;
final ChannelPipeline peerPipeline = peer.pipeline();
final EventLoop peerLoop = peer.eventLoop();
if (peerLoop == eventLoop()) {
for (;;) {
Object msg = in.current();
if (msg == null) {
break;
}
peer.inboundBuffer.add(msg);
ReferenceCountUtil.retain(msg);
in.remove();
}
finishPeerRead(peer, peerPipeline);
} else {
// Use a copy because the original msgs will be recycled by AbstractChannel.
final Object[] msgsCopy = new Object[in.size()];
for (int i = 0; i < msgsCopy.length; i ++) {
msgsCopy[i] = ReferenceCountUtil.retain(in.current());
in.remove();
}
peerLoop.execute(new Runnable() {
@Override
public void run() {
Collections.addAll(peer.inboundBuffer, msgsCopy);
finishPeerRead(peer, peerPipeline);
}
});
}
}
private static void finishPeerRead(LocalChannel peer, ChannelPipeline peerPipeline) {
if (peer.readInProgress) {
peer.readInProgress = false;
for (;;) {
Object received = peer.inboundBuffer.poll();
if (received == null) {
break;
}
peerPipeline.fireChannelRead(received);
}
peerPipeline.fireChannelReadComplete();
}
}
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 == 2) {
Exception cause = new AlreadyConnectedException();
safeSetFailure(promise, cause);
pipeline().fireExceptionCaught(cause);
return;
}
if (connectPromise != null) {
throw new ConnectionPendingException();
}
connectPromise = promise;
if (state != 1) {
// 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 ChannelException("connection refused");
safeSetFailure(promise, cause);
close(voidPromise());
return;
}
LocalServerChannel serverChannel = (LocalServerChannel) boundChannel;
peer = serverChannel.serve(LocalChannel.this);
}
}
}