andreacavalli/netty5
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Simplify the construction of multi-threaded selector event loop

Browse Source 
- Hide InternalLogger from users
This commit is contained in:
Trustin Lee 2012-05-15 13:11:47 +09:00
parent 311f17f6ef
commit f00fadb9fd
12 changed files with 323 additions and 311 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
example/src/main/java/io/netty/example/echo/EchoClient.java
View File

@ -22,11 +22,10 @@ import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.EventLoop;
import io.netty.channel.MultithreadEventLoop;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.channel.socket.nio.SelectorEventLoop;
import io.netty.handler.logging.LogLevel;
import io.netty.handler.logging.LoggingHandler;
import io.netty.logging.InternalLogLevel;
import java.net.InetSocketAddress;
@ -50,7 +49,7 @@ public class EchoClient {
public void run() throws Exception {
// Create the required event loop.
EventLoop loop = new MultithreadEventLoop(SelectorEventLoop.FACTORY);
EventLoop loop = new SelectorEventLoop();
try {
// Configure the client.
ChannelBuilder b = new ChannelBuilder();
@ -62,7 +61,7 @@ public class EchoClient {
@Override
public void initChannel(Channel ch) throws Exception {
ChannelPipeline p = ch.pipeline();
p.addLast("logger", new LoggingHandler(InternalLogLevel.INFO));
p.addLast("logger", new LoggingHandler(LogLevel.INFO));
p.addLast("echoer", new EchoClientHandler(firstMessageSize));
}
});

14
example/src/main/java/io/netty/example/echo/EchoServer.java
View File

@ -21,12 +21,11 @@ import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.EventLoop;
import io.netty.channel.MultithreadEventLoop;
import io.netty.channel.ServerChannelBuilder;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.channel.socket.nio.SelectorEventLoop;
import io.netty.handler.logging.LogLevel;
import io.netty.handler.logging.LoggingHandler;
import io.netty.logging.InternalLogLevel;
import java.net.InetSocketAddress;
@ -43,21 +42,22 @@ public class EchoServer {
public void run() throws Exception {
// Create the required event loops.
EventLoop parentLoop = new MultithreadEventLoop(SelectorEventLoop.FACTORY);
EventLoop childLoop = new MultithreadEventLoop(SelectorEventLoop.FACTORY);
EventLoop parentLoop = new SelectorEventLoop();
EventLoop childLoop = new SelectorEventLoop();
try {
// Configure the server.
ServerChannelBuilder b = new ServerChannelBuilder();
b.parentEventLoop(parentLoop)
.childEventLoop(childLoop)
.parentChannel(new NioServerSocketChannel())
.childOption(ChannelOption.TCP_NODELAY, true)
.parentOption(ChannelOption.SO_BACKLOG, 24)
.localAddress(new InetSocketAddress(port))
.childEventLoop(childLoop)
.childOption(ChannelOption.TCP_NODELAY, true)
.childInitializer(new ChannelInitializer() {
@Override
public void initChannel(Channel ch) throws Exception {
ChannelPipeline p = ch.pipeline();
p.addLast("logger", new LoggingHandler(InternalLogLevel.INFO));
p.addLast("logger", new LoggingHandler(LogLevel.INFO));
p.addLast("echoer", new EchoServerHandler());
}
});

20
handler/src/main/java/io/netty/handler/logging/LogLevel.java Normal file
View File

@ -0,0 +1,20 @@
package io.netty.handler.logging;
import io.netty.logging.InternalLogLevel;
public enum LogLevel {
DEBUG(InternalLogLevel.DEBUG),
INFO(InternalLogLevel.INFO),
WARN(InternalLogLevel.WARN),
ERROR(InternalLogLevel.ERROR);
private final InternalLogLevel internalLevel;
LogLevel(InternalLogLevel internalLevel) {
this.internalLevel = internalLevel;
}
InternalLogLevel toInternalLevel() {
return internalLevel;
}
}

85
handler/src/main/java/io/netty/handler/logging/LoggingHandler.java
View File

@ -42,7 +42,7 @@ import java.util.Queue;
@Sharable
public class LoggingHandler extends ChannelHandlerAdapter<Object, Object> {
private static final InternalLogLevel DEFAULT_LEVEL = InternalLogLevel.DEBUG;
private static final LogLevel DEFAULT_LEVEL = LogLevel.DEBUG;
private static final String NEWLINE = String.format("%n");
private static final String[] BYTE2HEX = new String[256];
@ -104,7 +104,8 @@ public class LoggingHandler extends ChannelHandlerAdapter<Object, Object> {
}
private final InternalLogger logger;
private final InternalLogLevel level;
private final LogLevel level;
private final InternalLogLevel internalLevel;
/**
* Creates a new instance whose logger name is the fully qualified class
@ -120,13 +121,14 @@ public class LoggingHandler extends ChannelHandlerAdapter<Object, Object> {
*
* @param level the log level
*/
public LoggingHandler(InternalLogLevel level) {
public LoggingHandler(LogLevel level) {
if (level == null) {
throw new NullPointerException("level");
}
logger = InternalLoggerFactory.getInstance(getClass());
this.level = level;
internalLevel = level.toInternalLevel();
}
/**
@ -142,7 +144,7 @@ public class LoggingHandler extends ChannelHandlerAdapter<Object, Object> {
*
* @param level the log level
*/
public LoggingHandler(Class<?> clazz, InternalLogLevel level) {
public LoggingHandler(Class<?> clazz, LogLevel level) {
if (clazz == null) {
throw new NullPointerException("clazz");
}
@ -151,34 +153,22 @@ public class LoggingHandler extends ChannelHandlerAdapter<Object, Object> {
}
logger = InternalLoggerFactory.getInstance(clazz);
this.level = level;
}
/**
* Creates a new instance with the specified logger name and with hex dump
* enabled.
*/
public LoggingHandler(String name) {
this(name, true);
internalLevel = level.toInternalLevel();
}
/**
* Creates a new instance with the specified logger name.
*
* @param hexDump {@code true} if and only if the hex dump of the received
* message is logged
*/
public LoggingHandler(String name, boolean hexDump) {
this(name, DEFAULT_LEVEL, hexDump);
public LoggingHandler(String name) {
this(name, DEFAULT_LEVEL);
}
/**
* Creates a new instance with the specified logger name.
*
* @param level the log level
* @param hexDump {@code true} if and only if the hex dump of the received
* message is logged
*/
public LoggingHandler(String name, InternalLogLevel level, boolean hexDump) {
public LoggingHandler(String name, LogLevel level) {
if (name == null) {
throw new NullPointerException("name");
}
@ -187,6 +177,7 @@ public class LoggingHandler extends ChannelHandlerAdapter<Object, Object> {
}
logger = InternalLoggerFactory.getInstance(name);
this.level = level;
internalLevel = level.toInternalLevel();
}
/**
@ -201,7 +192,7 @@ public class LoggingHandler extends ChannelHandlerAdapter<Object, Object> {
* Returns the {@link InternalLogLevel} that this handler uses to log
* a {@link ChannelEvent}.
*/
public InternalLogLevel getLevel() {
public LogLevel getLevel() {
return level;
}
@ -306,8 +297,8 @@ public class LoggingHandler extends ChannelHandlerAdapter<Object, Object> {
@Override
public void channelRegistered(ChannelInboundHandlerContext<Object> ctx)
throws Exception {
if (getLogger().isEnabled(level)) {
logger.log(level, format(ctx, "REGISTERED"));
if (getLogger().isEnabled(internalLevel)) {
logger.log(internalLevel, format(ctx, "REGISTERED"));
}
super.channelRegistered(ctx);
}
@ -315,8 +306,8 @@ public class LoggingHandler extends ChannelHandlerAdapter<Object, Object> {
@Override
public void channelUnregistered(ChannelInboundHandlerContext<Object> ctx)
throws Exception {
if (getLogger().isEnabled(level)) {
logger.log(level, format(ctx, "UNREGISTERED"));
if (getLogger().isEnabled(internalLevel)) {
logger.log(internalLevel, format(ctx, "UNREGISTERED"));
}
super.channelUnregistered(ctx);
}
@ -324,8 +315,8 @@ public class LoggingHandler extends ChannelHandlerAdapter<Object, Object> {
@Override
public void channelActive(ChannelInboundHandlerContext<Object> ctx)
throws Exception {
if (getLogger().isEnabled(level)) {
logger.log(level, format(ctx, "ACTIVE"));
if (getLogger().isEnabled(internalLevel)) {
logger.log(internalLevel, format(ctx, "ACTIVE"));
}
super.channelActive(ctx);
}
@ -333,8 +324,8 @@ public class LoggingHandler extends ChannelHandlerAdapter<Object, Object> {
@Override
public void channelInactive(ChannelInboundHandlerContext<Object> ctx)
throws Exception {
if (getLogger().isEnabled(level)) {
logger.log(level, format(ctx, "INACTIVE"));
if (getLogger().isEnabled(internalLevel)) {
logger.log(internalLevel, format(ctx, "INACTIVE"));
}
super.channelInactive(ctx);
}
@ -342,8 +333,8 @@ public class LoggingHandler extends ChannelHandlerAdapter<Object, Object> {
@Override
public void exceptionCaught(ChannelInboundHandlerContext<Object> ctx,
Throwable cause) throws Exception {
if (getLogger().isEnabled(level)) {
logger.log(level, format(ctx, "EXCEPTION: " + cause), cause);
if (getLogger().isEnabled(internalLevel)) {
logger.log(internalLevel, format(ctx, "EXCEPTION: " + cause), cause);
}
super.exceptionCaught(ctx, cause);
}
@ -351,8 +342,8 @@ public class LoggingHandler extends ChannelHandlerAdapter<Object, Object> {
@Override
public void userEventTriggered(ChannelInboundHandlerContext<Object> ctx,
Object evt) throws Exception {
if (getLogger().isEnabled(level)) {
logger.log(level, format(ctx, "USER_EVENT: " + evt));
if (getLogger().isEnabled(internalLevel)) {
logger.log(internalLevel, format(ctx, "USER_EVENT: " + evt));
}
super.userEventTriggered(ctx, evt);
}
@ -360,8 +351,8 @@ public class LoggingHandler extends ChannelHandlerAdapter<Object, Object> {
@Override
public void inboundBufferUpdated(ChannelInboundHandlerContext<Object> ctx)
throws Exception {
if (getLogger().isEnabled(level)) {
logger.log(level, format(ctx, formatBuffer("INBUF", ctx.in())));
if (getLogger().isEnabled(internalLevel)) {
logger.log(internalLevel, format(ctx, formatBuffer("INBUF", ctx.in())));
}
ctx.fireInboundBufferUpdated();
}
@ -369,8 +360,8 @@ public class LoggingHandler extends ChannelHandlerAdapter<Object, Object> {
@Override
public void bind(ChannelOutboundHandlerContext<Object> ctx,
SocketAddress localAddress, ChannelFuture future) throws Exception {
if (getLogger().isEnabled(level)) {
logger.log(level, format(ctx, "BIND(" + localAddress + ')'));
if (getLogger().isEnabled(internalLevel)) {
logger.log(internalLevel, format(ctx, "BIND(" + localAddress + ')'));
}
super.bind(ctx, localAddress, future);
}
@ -379,8 +370,8 @@ public class LoggingHandler extends ChannelHandlerAdapter<Object, Object> {
public void connect(ChannelOutboundHandlerContext<Object> ctx,
SocketAddress remoteAddress, SocketAddress localAddress,
ChannelFuture future) throws Exception {
if (getLogger().isEnabled(level)) {
logger.log(level, format(ctx, "CONNECT(" + remoteAddress + ", " + localAddress + ')'));
if (getLogger().isEnabled(internalLevel)) {
logger.log(internalLevel, format(ctx, "CONNECT(" + remoteAddress + ", " + localAddress + ')'));
}
super.connect(ctx, remoteAddress, localAddress, future);
}
@ -388,8 +379,8 @@ public class LoggingHandler extends ChannelHandlerAdapter<Object, Object> {
@Override
public void disconnect(ChannelOutboundHandlerContext<Object> ctx,
ChannelFuture future) throws Exception {
if (getLogger().isEnabled(level)) {
logger.log(level, format(ctx, "DISCONNECT()"));
if (getLogger().isEnabled(internalLevel)) {
logger.log(internalLevel, format(ctx, "DISCONNECT()"));
}
super.disconnect(ctx, future);
}
@ -397,8 +388,8 @@ public class LoggingHandler extends ChannelHandlerAdapter<Object, Object> {
@Override
public void close(ChannelOutboundHandlerContext<Object> ctx,
ChannelFuture future) throws Exception {
if (getLogger().isEnabled(level)) {
logger.log(level, format(ctx, "CLOSE()"));
if (getLogger().isEnabled(internalLevel)) {
logger.log(internalLevel, format(ctx, "CLOSE()"));
}
super.close(ctx, future);
}
@ -406,8 +397,8 @@ public class LoggingHandler extends ChannelHandlerAdapter<Object, Object> {
@Override
public void deregister(ChannelOutboundHandlerContext<Object> ctx,
ChannelFuture future) throws Exception {
if (getLogger().isEnabled(level)) {
logger.log(level, format(ctx, "DEREGISTER()"));
if (getLogger().isEnabled(internalLevel)) {
logger.log(internalLevel, format(ctx, "DEREGISTER()"));
}
super.deregister(ctx, future);
}
@ -415,8 +406,8 @@ public class LoggingHandler extends ChannelHandlerAdapter<Object, Object> {
@Override
public void flush(ChannelOutboundHandlerContext<Object> ctx,
ChannelFuture future) throws Exception {
if (getLogger().isEnabled(level)) {
logger.log(level, format(ctx, formatBuffer("OUTBUF", ctx.prevOut())));
if (getLogger().isEnabled(internalLevel)) {
logger.log(internalLevel, format(ctx, formatBuffer("OUTBUF", ctx.prevOut())));
}
ctx.flush(future);
}

1
transport/src/main/java/io/netty/channel/ChannelInitializer.java
View File

@ -43,7 +43,6 @@ public abstract class ChannelInitializer extends ChannelInboundHandlerAdapter<Ob
ctx.pipeline().remove(this);
// Note that we do not call ctx.fireChannelRegistered() because a user might have
// inserted a handler before the initializer using pipeline.addFirst().
System.out.println(ctx.pipeline().toMap());
ctx.pipeline().fireChannelRegistered();
} catch (Throwable t) {
logger.warn("Failed to initialize a channel. Closing: " + ctx.channel());

7
transport/src/main/java/io/netty/channel/MultithreadEventLoop.java
View File

@ -15,15 +15,18 @@ import java.util.concurrent.atomic.AtomicInteger;
public class MultithreadEventLoop implements EventLoop {
protected static final int DEFAULT_POOL_SIZE = Runtime.getRuntime().availableProcessors() * 2;
protected static final ThreadFactory DEFAULT_THREAD_FACTORY = Executors.defaultThreadFactory();
private final EventLoop[] children;
private final AtomicInteger childIndex = new AtomicInteger();
public MultithreadEventLoop(EventLoopFactory<? extends SingleThreadEventLoop> loopFactory) {
this(loopFactory, Runtime.getRuntime().availableProcessors() * 2);
this(loopFactory, DEFAULT_POOL_SIZE);
}
public MultithreadEventLoop(EventLoopFactory<? extends SingleThreadEventLoop> loopFactory, int nThreads) {
this(loopFactory, nThreads, Executors.defaultThreadFactory());
this(loopFactory, nThreads, DEFAULT_THREAD_FACTORY);
}
public MultithreadEventLoop(EventLoopFactory<? extends SingleThreadEventLoop> loopFactory, int nThreads, ThreadFactory threadFactory) {

9
transport/src/main/java/io/netty/channel/socket/nio/AbstractNioChannel.java
View File

@ -37,11 +37,6 @@ public abstract class AbstractNioChannel extends AbstractChannel {
this.ch = ch;
}
@Override
public SelectorEventLoop eventLoop() {
return (SelectorEventLoop) super.eventLoop();
}
@Override
protected SelectableChannel javaChannel() {
return ch;
@ -84,12 +79,12 @@ public abstract class AbstractNioChannel extends AbstractChannel {
@Override
protected boolean isCompatible(EventLoop loop) {
return loop instanceof SelectorEventLoop;
return loop instanceof SingleThreadSelectorEventLoop;
}
@Override
protected void doRegister() throws Exception {
SelectorEventLoop loop = eventLoop();
SingleThreadSelectorEventLoop loop = (SingleThreadSelectorEventLoop) eventLoop();
selectionKey = javaChannel().register(loop.selector, isActive()? SelectionKey.OP_READ : 0, this);
}

2
transport/src/main/java/io/netty/channel/socket/nio/NioDatagramWorker.java
View File

@ -43,7 +43,7 @@ import java.util.concurrent.Executor;
* A class responsible for registering channels with {@link Selector}.
* It also implements the {@link Selector} loop.
*/
public class NioDatagramWorker extends SelectorEventLoop {
public class NioDatagramWorker extends SingleThreadSelectorEventLoop {
/**
* Sole constructor.

9
transport/src/main/java/io/netty/channel/socket/nio/NioServerSocketChannel.java
View File

@ -74,11 +74,6 @@ public class NioServerSocketChannel extends AbstractServerChannel
return config;
}
@Override
public SelectorEventLoop eventLoop() {
return (SelectorEventLoop) super.eventLoop();
}
@Override
public boolean isActive() {
return javaChannel().socket().isBound();
@ -116,12 +111,12 @@ public class NioServerSocketChannel extends AbstractServerChannel
@Override
protected boolean isCompatible(EventLoop loop) {
return loop instanceof SelectorEventLoop;
return loop instanceof SingleThreadSelectorEventLoop;
}
@Override
protected void doRegister() throws Exception {
SelectorEventLoop loop = eventLoop();
SingleThreadSelectorEventLoop loop = (SingleThreadSelectorEventLoop) eventLoop();
selectionKey = javaChannel().register(
loop.selector, isActive()? SelectionKey.OP_ACCEPT : 0, this);
}

2
transport/src/main/java/io/netty/channel/socket/nio/NioSocketChannel.java
View File

@ -152,7 +152,7 @@ public class NioSocketChannel extends AbstractNioChannel implements io.netty.cha
@Override
protected void doDeregister() throws Exception {
selectionKey().cancel();
eventLoop().cancelledKeys ++;
((SingleThreadSelectorEventLoop) eventLoop()).cancelledKeys ++;
}
@Override

247
transport/src/main/java/io/netty/channel/socket/nio/SelectorEventLoop.java
View File

@ -1,253 +1,32 @@
/*
* Copyright 2011 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.socket.nio;
import io.netty.channel.Channel;
import io.netty.channel.Channel.Unsafe;
import io.netty.channel.ChannelException;
import io.netty.channel.EventLoopFactory;
import io.netty.channel.SingleThreadEventLoop;
import io.netty.logging.InternalLogger;
import io.netty.logging.InternalLoggerFactory;
import io.netty.channel.MultithreadEventLoop;
import java.io.IOException;
import java.nio.channels.CancelledKeyException;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.spi.SelectorProvider;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.Set;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.atomic.AtomicBoolean;
public class SelectorEventLoop extends SingleThreadEventLoop {
public static final EventLoopFactory<SelectorEventLoop> FACTORY = new EventLoopFactory<SelectorEventLoop>() {
@Override
public SelectorEventLoop newEventLoop(ThreadFactory threadFactory)
throws Exception {
return new SelectorEventLoop(threadFactory);
}
};
/**
* Internal Netty logger.
*/
protected static final InternalLogger logger = InternalLoggerFactory
.getInstance(SelectorEventLoop.class);
static final int CLEANUP_INTERVAL = 256; // XXX Hard-coded value, but won't need customization.
/**
* The NIO {@link Selector}.
*/
protected final Selector selector;
/**
* Boolean that controls determines if a blocked Selector.select should
* break out of its selection process. In our case we use a timeone for
* the select method and the select method will block for that time unless
* waken up.
*/
protected final AtomicBoolean wakenUp = new AtomicBoolean();
int cancelledKeys;
public class SelectorEventLoop extends MultithreadEventLoop {
public SelectorEventLoop() {
this(Executors.defaultThreadFactory());
this(DEFAULT_POOL_SIZE);
}
public SelectorEventLoop(ThreadFactory threadFactory) {
this(threadFactory, SelectorProvider.provider());
public SelectorEventLoop(int nThreads) {
this(nThreads, DEFAULT_THREAD_FACTORY);
}
public SelectorEventLoop(SelectorProvider selectorProvider) {
this(Executors.defaultThreadFactory(), selectorProvider);
public SelectorEventLoop(int nThreads, ThreadFactory threadFactory) {
this(nThreads, threadFactory, SelectorProvider.provider());
}
public SelectorEventLoop(ThreadFactory threadFactory, SelectorProvider selectorProvider) {
super(threadFactory);
if (selectorProvider == null) {
throw new NullPointerException("selectorProvider");
}
selector = openSelector(selectorProvider);
}
private static Selector openSelector(SelectorProvider provider) {
try {
return provider.openSelector();
} catch (IOException e) {
throw new ChannelException("failed to open a new selector", e);
}
}
@Override
protected void run() {
Selector selector = this.selector;
for (;;) {
wakenUp.set(false);
try {
SelectorUtil.select(selector);
// '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();
}
cancelledKeys = 0;
processTaskQueue();
processSelectedKeys();
if (isShutdown()) {
closeAll();
break;
}
} catch (Throwable t) {
logger.warn(
"Unexpected exception in the selector loop.", t);
// Prevent possible consecutive immediate failures that lead to
// excessive CPU consumption.
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// Ignore.
}
}
}
}
@Override
protected void cleanup() {
try {
selector.close();
} catch (IOException e) {
logger.warn(
"Failed to close a selector.", e);
}
}
private void processTaskQueue() {
for (;;) {
final Runnable task = pollTask();
if (task == null) {
break;
public SelectorEventLoop(int nThreads, ThreadFactory threadFactory, final SelectorProvider selectorProvider) {
super(new EventLoopFactory<SingleThreadSelectorEventLoop>() {
@Override
public SingleThreadSelectorEventLoop newEventLoop(ThreadFactory threadFactory) throws Exception {
return new SingleThreadSelectorEventLoop(threadFactory, selectorProvider);
}
task.run();
cleanUpCancelledKeys();
}
}
private void processSelectedKeys() {
for (Iterator<SelectionKey> i = selector.selectedKeys().iterator(); i.hasNext();) {
final SelectionKey k = i.next();
final Channel ch = (Channel) k.attachment();
final Unsafe unsafe = ch.unsafe();
boolean removeKey = true;
try {
int readyOps = k.readyOps();
if ((readyOps & SelectionKey.OP_READ) != 0 || readyOps == 0) {
unsafe.read();
if (!ch.isOpen()) {
// Connection already closed - no need to handle write.
continue;
}
}
if ((readyOps & SelectionKey.OP_WRITE) != 0) {
unsafe.flushForcibly();
}
if ((readyOps & SelectionKey.OP_ACCEPT) != 0) {
unsafe.read();
}
if ((readyOps & SelectionKey.OP_CONNECT) != 0) {
unsafe.finishConnect();
}
} catch (CancelledKeyException ignored) {
unsafe.close(unsafe.voidFuture());
} finally {
if (removeKey) {
i.remove();
}
}
if (cleanUpCancelledKeys()) {
break; // break the loop to avoid ConcurrentModificationException
}
}
}
private boolean cleanUpCancelledKeys() {
if (cancelledKeys >= CLEANUP_INTERVAL) {
cancelledKeys = 0;
SelectorUtil.cleanupKeys(selector);
return true;
}
return false;
}
private void closeAll() {
SelectorUtil.cleanupKeys(selector);
Set<SelectionKey> keys = selector.keys();
Collection<Channel> channels = new ArrayList<Channel>(keys.size());
for (SelectionKey k: keys) {
channels.add((Channel) k.attachment());
}
for (Channel ch: channels) {
ch.unsafe().close(ch.unsafe().voidFuture());
}
}
@Override
protected void wakeup(boolean inEventLoop) {
if (wakenUp.compareAndSet(false, true)) {
selector.wakeup();
}
}, nThreads, threadFactory);
}
}

231
transport/src/main/java/io/netty/channel/socket/nio/SingleThreadSelectorEventLoop.java Normal file
View File

@ -0,0 +1,231 @@
/*
* Copyright 2011 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.socket.nio;
import io.netty.channel.Channel;
import io.netty.channel.Channel.Unsafe;
import io.netty.channel.ChannelException;
import io.netty.channel.SingleThreadEventLoop;
import io.netty.logging.InternalLogger;
import io.netty.logging.InternalLoggerFactory;
import java.io.IOException;
import java.nio.channels.CancelledKeyException;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.spi.SelectorProvider;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.Set;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.atomic.AtomicBoolean;
final class SingleThreadSelectorEventLoop extends SingleThreadEventLoop {
/**
* Internal Netty logger.
*/
protected static final InternalLogger logger = InternalLoggerFactory
.getInstance(SingleThreadSelectorEventLoop.class);
static final int CLEANUP_INTERVAL = 256; // XXX Hard-coded value, but won't need customization.
/**
* The NIO {@link Selector}.
*/
protected final Selector selector;
/**
* Boolean that controls determines if a blocked Selector.select should
* break out of its selection process. In our case we use a timeone for
* the select method and the select method will block for that time unless
* waken up.
*/
protected final AtomicBoolean wakenUp = new AtomicBoolean();
int cancelledKeys;
SingleThreadSelectorEventLoop(ThreadFactory threadFactory, SelectorProvider selectorProvider) {
super(threadFactory);
if (selectorProvider == null) {
throw new NullPointerException("selectorProvider");
}
selector = openSelector(selectorProvider);
}
private static Selector openSelector(SelectorProvider provider) {
try {
return provider.openSelector();
} catch (IOException e) {
throw new ChannelException("failed to open a new selector", e);
}
}
@Override
protected void run() {
Selector selector = this.selector;
for (;;) {
wakenUp.set(false);
try {
SelectorUtil.select(selector);
// '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();
}
cancelledKeys = 0;
processTaskQueue();
processSelectedKeys();
if (isShutdown()) {
closeAll();
break;
}
} catch (Throwable t) {
logger.warn(
"Unexpected exception in the selector loop.", t);
// Prevent possible consecutive immediate failures that lead to
// excessive CPU consumption.
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// Ignore.
}
}
}
}
@Override
protected void cleanup() {
try {
selector.close();
} catch (IOException e) {
logger.warn(
"Failed to close a selector.", e);
}
}
private void processTaskQueue() {
for (;;) {
final Runnable task = pollTask();
if (task == null) {
break;
}
task.run();
cleanUpCancelledKeys();
}
}
private void processSelectedKeys() {
for (Iterator<SelectionKey> i = selector.selectedKeys().iterator(); i.hasNext();) {
final SelectionKey k = i.next();
final Channel ch = (Channel) k.attachment();
final Unsafe unsafe = ch.unsafe();
boolean removeKey = true;
try {
int readyOps = k.readyOps();
if ((readyOps & SelectionKey.OP_READ) != 0 || readyOps == 0) {
unsafe.read();
if (!ch.isOpen()) {
// Connection already closed - no need to handle write.
continue;
}
}
if ((readyOps & SelectionKey.OP_WRITE) != 0) {
unsafe.flushForcibly();
}
if ((readyOps & SelectionKey.OP_ACCEPT) != 0) {
unsafe.read();
}
if ((readyOps & SelectionKey.OP_CONNECT) != 0) {
unsafe.finishConnect();
}
} catch (CancelledKeyException ignored) {
unsafe.close(unsafe.voidFuture());
} finally {
if (removeKey) {
i.remove();
}
}
if (cleanUpCancelledKeys()) {
break; // break the loop to avoid ConcurrentModificationException
}
}
}
private boolean cleanUpCancelledKeys() {
if (cancelledKeys >= CLEANUP_INTERVAL) {
cancelledKeys = 0;
SelectorUtil.cleanupKeys(selector);
return true;
}
return false;
}
private void closeAll() {
SelectorUtil.cleanupKeys(selector);
Set<SelectionKey> keys = selector.keys();
Collection<Channel> channels = new ArrayList<Channel>(keys.size());
for (SelectionKey k: keys) {
channels.add((Channel) k.attachment());
}
for (Channel ch: channels) {
ch.unsafe().close(ch.unsafe().voidFuture());
}
}
@Override
protected void wakeup(boolean inEventLoop) {
if (wakenUp.compareAndSet(false, true)) {
selector.wakeup();
}
}
}