org.jboss.netty.channel.socket.nio.NioClientSocketPipelineSink Maven / Gradle / Ivy
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The Netty project is an effort to provide an asynchronous event-driven
network application framework and tools for rapid development of
maintainable high performance and high scalability protocol servers and
clients. In other words, Netty is a NIO client server framework which
enables quick and easy development of network applications such as protocol
servers and clients. It greatly simplifies and streamlines network
programming such as TCP and UDP socket server.
/*
* Copyright 2009 Red Hat, Inc.
*
* Red Hat 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 org.jboss.netty.channel.socket.nio;
import static org.jboss.netty.channel.Channels.*;
import java.io.IOException;
import java.net.ConnectException;
import java.net.SocketAddress;
import java.nio.channels.ClosedChannelException;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.util.Iterator;
import java.util.Queue;
import java.util.Set;
import java.util.concurrent.Executor;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import org.jboss.netty.channel.AbstractChannelSink;
import org.jboss.netty.channel.ChannelEvent;
import org.jboss.netty.channel.ChannelException;
import org.jboss.netty.channel.ChannelFuture;
import org.jboss.netty.channel.ChannelFutureListener;
import org.jboss.netty.channel.ChannelPipeline;
import org.jboss.netty.channel.ChannelState;
import org.jboss.netty.channel.ChannelStateEvent;
import org.jboss.netty.channel.MessageEvent;
import org.jboss.netty.logging.InternalLogger;
import org.jboss.netty.logging.InternalLoggerFactory;
import org.jboss.netty.util.ThreadRenamingRunnable;
import org.jboss.netty.util.internal.DeadLockProofWorker;
import org.jboss.netty.util.internal.LinkedTransferQueue;
/**
*
* @author The Netty Project
* @author Trustin Lee
*
* @version $Rev: 2144 $, $Date: 2010-02-09 12:41:12 +0900 (Tue, 09 Feb 2010) $
*
*/
class NioClientSocketPipelineSink extends AbstractChannelSink {
static final InternalLogger logger =
InternalLoggerFactory.getInstance(NioClientSocketPipelineSink.class);
private static final AtomicInteger nextId = new AtomicInteger();
final int id = nextId.incrementAndGet();
final Executor bossExecutor;
private final Boss boss = new Boss();
private final NioWorker[] workers;
private final AtomicInteger workerIndex = new AtomicInteger();
NioClientSocketPipelineSink(
Executor bossExecutor, Executor workerExecutor, int workerCount) {
this.bossExecutor = bossExecutor;
workers = new NioWorker[workerCount];
for (int i = 0; i < workers.length; i ++) {
workers[i] = new NioWorker(id, i + 1, workerExecutor);
}
}
public void eventSunk(
ChannelPipeline pipeline, ChannelEvent e) throws Exception {
if (e instanceof ChannelStateEvent) {
ChannelStateEvent event = (ChannelStateEvent) e;
NioClientSocketChannel channel =
(NioClientSocketChannel) event.getChannel();
ChannelFuture future = event.getFuture();
ChannelState state = event.getState();
Object value = event.getValue();
switch (state) {
case OPEN:
if (Boolean.FALSE.equals(value)) {
channel.worker.close(channel, future);
}
break;
case BOUND:
if (value != null) {
bind(channel, future, (SocketAddress) value);
} else {
channel.worker.close(channel, future);
}
break;
case CONNECTED:
if (value != null) {
connect(channel, future, (SocketAddress) value);
} else {
channel.worker.close(channel, future);
}
break;
case INTEREST_OPS:
channel.worker.setInterestOps(channel, future, ((Integer) value).intValue());
break;
}
} else if (e instanceof MessageEvent) {
MessageEvent event = (MessageEvent) e;
NioSocketChannel channel = (NioSocketChannel) event.getChannel();
boolean offered = channel.writeBuffer.offer(event);
assert offered;
channel.worker.writeFromUserCode(channel);
}
}
private void bind(
NioClientSocketChannel channel, ChannelFuture future,
SocketAddress localAddress) {
try {
channel.socket.socket().bind(localAddress);
channel.boundManually = true;
channel.setBound();
future.setSuccess();
fireChannelBound(channel, channel.getLocalAddress());
} catch (Throwable t) {
future.setFailure(t);
fireExceptionCaught(channel, t);
}
}
private void connect(
final NioClientSocketChannel channel, final ChannelFuture cf,
SocketAddress remoteAddress) {
try {
if (channel.socket.connect(remoteAddress)) {
channel.worker.register(channel, cf);
} else {
channel.getCloseFuture().addListener(new ChannelFutureListener() {
public void operationComplete(ChannelFuture f)
throws Exception {
if (!cf.isDone()) {
cf.setFailure(new ClosedChannelException());
}
}
});
cf.addListener(ChannelFutureListener.CLOSE_ON_FAILURE);
channel.connectFuture = cf;
boss.register(channel);
}
} catch (Throwable t) {
cf.setFailure(t);
fireExceptionCaught(channel, t);
channel.worker.close(channel, succeededFuture(channel));
}
}
NioWorker nextWorker() {
return workers[Math.abs(
workerIndex.getAndIncrement() % workers.length)];
}
private final class Boss implements Runnable {
volatile Selector selector;
private boolean started;
private final AtomicBoolean wakenUp = new AtomicBoolean();
private final Object startStopLock = new Object();
private final Queue registerTaskQueue = new LinkedTransferQueue();
Boss() {
super();
}
void register(NioClientSocketChannel channel) {
Runnable registerTask = new RegisterTask(this, channel);
Selector selector;
synchronized (startStopLock) {
if (!started) {
// Open a selector if this worker didn't start yet.
try {
this.selector = selector = Selector.open();
} catch (Throwable t) {
throw new ChannelException(
"Failed to create a selector.", t);
}
// Start the worker thread with the new Selector.
boolean success = false;
try {
DeadLockProofWorker.start(
bossExecutor,
new ThreadRenamingRunnable(
this, "New I/O client boss #" + id));
success = true;
} finally {
if (!success) {
// Release the Selector if the execution fails.
try {
selector.close();
} catch (Throwable t) {
logger.warn("Failed to close a selector.", t);
}
this.selector = selector = null;
// The method will return to the caller at this point.
}
}
} else {
// Use the existing selector if this worker has been started.
selector = this.selector;
}
assert selector != null && selector.isOpen();
started = true;
boolean offered = registerTaskQueue.offer(registerTask);
assert offered;
}
if (wakenUp.compareAndSet(false, true)) {
selector.wakeup();
}
}
public void run() {
boolean shutdown = false;
Selector selector = this.selector;
long lastConnectTimeoutCheckTimeNanos = System.nanoTime();
for (;;) {
wakenUp.set(false);
try {
int selectedKeyCount = selector.select(500);
// 'wakenUp.compareAndSet(false, true)' is always evaluated
// before calling 'selector.wakeup()' to reduce the wake-up
// overhead. (Selector.wakeup() is an expensive operation.)
//
// However, there is a race condition in this approach.
// The race condition is triggered when 'wakenUp' is set to
// true too early.
//
// 'wakenUp' is set to true too early if:
// 1) Selector is waken up between 'wakenUp.set(false)' and
// 'selector.select(...)'. (BAD)
// 2) Selector is waken up between 'selector.select(...)' and
// 'if (wakenUp.get()) { ... }'. (OK)
//
// In the first case, 'wakenUp' is set to true and the
// following 'selector.select(...)' will wake up immediately.
// Until 'wakenUp' is set to false again in the next round,
// 'wakenUp.compareAndSet(false, true)' will fail, and therefore
// any attempt to wake up the Selector will fail, too, causing
// the following 'selector.select(...)' call to block
// unnecessarily.
//
// To fix this problem, we wake up the selector again if wakenUp
// is true immediately after selector.select(...).
// It is inefficient in that it wakes up the selector for both
// the first case (BAD - wake-up required) and the second case
// (OK - no wake-up required).
if (wakenUp.get()) {
selector.wakeup();
}
processRegisterTaskQueue();
if (selectedKeyCount > 0) {
processSelectedKeys(selector.selectedKeys());
}
// Handle connection timeout every 0.5 seconds approximately.
long currentTimeNanos = System.nanoTime();
if (currentTimeNanos - lastConnectTimeoutCheckTimeNanos >= 500 * 1000000L) {
lastConnectTimeoutCheckTimeNanos = currentTimeNanos;
processConnectTimeout(selector.keys(), currentTimeNanos);
}
// Exit the loop when there's nothing to handle.
// The shutdown flag is used to delay the shutdown of this
// loop to avoid excessive Selector creation when
// connection attempts are made in a one-by-one manner
// instead of concurrent manner.
if (selector.keys().isEmpty()) {
if (shutdown ||
bossExecutor instanceof ExecutorService && ((ExecutorService) bossExecutor).isShutdown()) {
synchronized (startStopLock) {
if (registerTaskQueue.isEmpty() && selector.keys().isEmpty()) {
started = false;
try {
selector.close();
} catch (IOException e) {
logger.warn(
"Failed to close a selector.", e);
} finally {
this.selector = null;
}
break;
} else {
shutdown = false;
}
}
} else {
// Give one more second.
shutdown = true;
}
} else {
shutdown = false;
}
} catch (Throwable t) {
logger.warn(
"Unexpected exception in the selector loop.", t);
// Prevent possible consecutive immediate failures.
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// Ignore.
}
}
}
}
private void processRegisterTaskQueue() {
for (;;) {
final Runnable task = registerTaskQueue.poll();
if (task == null) {
break;
}
task.run();
}
}
private void processSelectedKeys(Set selectedKeys) {
for (Iterator i = selectedKeys.iterator(); i.hasNext();) {
SelectionKey k = i.next();
i.remove();
if (!k.isValid()) {
close(k);
continue;
}
if (k.isConnectable()) {
connect(k);
}
}
}
private void processConnectTimeout(Set keys, long currentTimeNanos) {
ConnectException cause = null;
for (SelectionKey k: keys) {
if (!k.isValid()) {
continue;
}
NioClientSocketChannel ch = (NioClientSocketChannel) k.attachment();
if (ch.connectDeadlineNanos > 0 &&
currentTimeNanos >= ch.connectDeadlineNanos) {
if (cause == null) {
cause = new ConnectException("connection timed out");
}
ch.connectFuture.setFailure(cause);
fireExceptionCaught(ch, cause);
ch.worker.close(ch, succeededFuture(ch));
}
}
}
private void connect(SelectionKey k) {
NioClientSocketChannel ch = (NioClientSocketChannel) k.attachment();
try {
if (ch.socket.finishConnect()) {
k.cancel();
ch.worker.register(ch, ch.connectFuture);
}
} catch (Throwable t) {
ch.connectFuture.setFailure(t);
fireExceptionCaught(ch, t);
k.cancel(); // Some JDK implementations run into an infinite loop without this.
ch.worker.close(ch, succeededFuture(ch));
}
}
private void close(SelectionKey k) {
NioClientSocketChannel ch = (NioClientSocketChannel) k.attachment();
ch.worker.close(ch, succeededFuture(ch));
}
}
private static final class RegisterTask implements Runnable {
private final Boss boss;
private final NioClientSocketChannel channel;
RegisterTask(Boss boss, NioClientSocketChannel channel) {
this.boss = boss;
this.channel = channel;
}
public void run() {
try {
channel.socket.register(
boss.selector, SelectionKey.OP_CONNECT, channel);
} catch (ClosedChannelException e) {
channel.worker.close(channel, succeededFuture(channel));
}
int connectTimeout = channel.getConfig().getConnectTimeoutMillis();
if (connectTimeout > 0) {
channel.connectDeadlineNanos = System.nanoTime() + connectTimeout * 1000000L;
}
}
}
}
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