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Start to refactor nio transport to share more code. See #186

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This commit is contained in:
Norman Maurer 2012-02-18 23:02:56 +01:00
parent 65be9ebd44
commit 812a9026b8
12 changed files with 1181 additions and 1872 deletions
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394
transport/src/main/java/io/netty/channel/socket/nio/AbstractNioChannel.java Normal file
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/*
* 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 static io.netty.channel.Channels.fireChannelInterestChanged;
import io.netty.buffer.ChannelBuffer;
import io.netty.channel.AbstractChannel;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFactory;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.ChannelSink;
import io.netty.channel.MessageEvent;
import io.netty.channel.socket.nio.SocketSendBufferPool.SendBuffer;
import io.netty.util.internal.QueueFactory;
import io.netty.util.internal.ThreadLocalBoolean;
import java.net.InetSocketAddress;
import java.net.SocketAddress;
import java.nio.channels.SelectableChannel;
import java.nio.channels.WritableByteChannel;
import java.util.Collection;
import java.util.Iterator;
import java.util.Queue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
abstract class AbstractNioChannel<C extends SelectableChannel & WritableByteChannel> extends AbstractChannel {
/**
* The {@link AbstractNioWorker}.
*/
final AbstractNioWorker worker;
/**
* Monitor object to synchronize access to InterestedOps.
*/
final Object interestOpsLock = new Object();
/**
* Monitor object for synchronizing access to the {@link WriteRequestQueue}.
*/
final Object writeLock = new Object();
/**
* WriteTask that performs write operations.
*/
final Runnable writeTask = new WriteTask();
/**
* Indicates if there is a {@link WriteTask} in the task queue.
*/
final AtomicBoolean writeTaskInTaskQueue = new AtomicBoolean();
/**
* Queue of write {@link MessageEvent}s.
*/
final Queue<MessageEvent> writeBufferQueue = new WriteRequestQueue();
/**
* Keeps track of the number of bytes that the {@link WriteRequestQueue} currently
* contains.
*/
final AtomicInteger writeBufferSize = new AtomicInteger();
/**
* Keeps track of the highWaterMark.
*/
final AtomicInteger highWaterMarkCounter = new AtomicInteger();
/**
* The current write {@link MessageEvent}
*/
MessageEvent currentWriteEvent;
SendBuffer currentWriteBuffer;
/**
* Boolean that indicates that write operation is in progress.
*/
boolean inWriteNowLoop;
boolean writeSuspended;
private volatile InetSocketAddress localAddress;
volatile InetSocketAddress remoteAddress;
final C channel;
protected AbstractNioChannel(Integer id, Channel parent, ChannelFactory factory, ChannelPipeline pipeline, ChannelSink sink, AbstractNioWorker worker, C ch) {
super(id, parent, factory, pipeline, sink);
this.worker = worker;
this.channel = ch;
}
protected AbstractNioChannel(
Channel parent, ChannelFactory factory,
ChannelPipeline pipeline, ChannelSink sink, AbstractNioWorker worker, C ch) {
super(parent, factory, pipeline, sink);
this.worker = worker;
this.channel = ch;
}
@Override
public InetSocketAddress getLocalAddress() {
InetSocketAddress localAddress = this.localAddress;
if (localAddress == null) {
try {
this.localAddress = localAddress =
(InetSocketAddress) getLocalSocketAddress();
} catch (Throwable t) {
// Sometimes fails on a closed socket in Windows.
return null;
}
}
return localAddress;
}
@Override
public InetSocketAddress getRemoteAddress() {
InetSocketAddress remoteAddress = this.remoteAddress;
if (remoteAddress == null) {
try {
this.remoteAddress = remoteAddress =
(InetSocketAddress) getRemoteSocketAddress();
} catch (Throwable t) {
// Sometimes fails on a closed socket in Windows.
return null;
}
}
return remoteAddress;
}
int getRawInterestOps() {
return super.getInterestOps();
}
void setRawInterestOpsNow(int interestOps) {
super.setInterestOpsNow(interestOps);
}
@Override
public ChannelFuture write(Object message, SocketAddress remoteAddress) {
if (remoteAddress == null || remoteAddress.equals(getRemoteAddress())) {
return super.write(message, null);
} else {
return getUnsupportedOperationFuture();
}
}
@Override
public int getInterestOps() {
if (!isOpen()) {
return Channel.OP_WRITE;
}
int interestOps = getRawInterestOps();
int writeBufferSize = this.writeBufferSize.get();
if (writeBufferSize != 0) {
if (highWaterMarkCounter.get() > 0) {
int lowWaterMark = ((NioChannelConfig) getConfig()).getWriteBufferLowWaterMark();
if (writeBufferSize >= lowWaterMark) {
interestOps |= Channel.OP_WRITE;
} else {
interestOps &= ~Channel.OP_WRITE;
}
} else {
int highWaterMark = ((NioChannelConfig) getConfig()).getWriteBufferHighWaterMark();
if (writeBufferSize >= highWaterMark) {
interestOps |= Channel.OP_WRITE;
} else {
interestOps &= ~Channel.OP_WRITE;
}
}
} else {
interestOps &= ~Channel.OP_WRITE;
}
return interestOps;
}
@Override
protected boolean setClosed() {
return super.setClosed();
}
abstract InetSocketAddress getLocalSocketAddress() throws Exception;
abstract InetSocketAddress getRemoteSocketAddress() throws Exception;
private final class WriteRequestQueue implements BlockingQueue<MessageEvent> {
private final ThreadLocalBoolean notifying = new ThreadLocalBoolean();
private final BlockingQueue<MessageEvent> queue;
public WriteRequestQueue() {
this.queue = QueueFactory.createQueue(MessageEvent.class);
}
@Override
public MessageEvent remove() {
return queue.remove();
}
@Override
public MessageEvent element() {
return queue.element();
}
@Override
public MessageEvent peek() {
return queue.peek();
}
@Override
public int size() {
return queue.size();
}
@Override
public boolean isEmpty() {
return queue.isEmpty();
}
@Override
public Iterator<MessageEvent> iterator() {
return queue.iterator();
}
@Override
public Object[] toArray() {
return queue.toArray();
}
@Override
public <T> T[] toArray(T[] a) {
return queue.toArray(a);
}
@Override
public boolean containsAll(Collection<?> c) {
return queue.containsAll(c);
}
@Override
public boolean addAll(Collection<? extends MessageEvent> c) {
return queue.addAll(c);
}
@Override
public boolean removeAll(Collection<?> c) {
return queue.removeAll(c);
}
@Override
public boolean retainAll(Collection<?> c) {
return queue.retainAll(c);
}
@Override
public void clear() {
queue.clear();
}
@Override
public boolean add(MessageEvent e) {
return queue.add(e);
}
@Override
public void put(MessageEvent e) throws InterruptedException {
queue.put(e);
}
@Override
public boolean offer(MessageEvent e, long timeout, TimeUnit unit) throws InterruptedException {
return queue.offer(e, timeout, unit);
}
@Override
public MessageEvent take() throws InterruptedException {
return queue.take();
}
@Override
public MessageEvent poll(long timeout, TimeUnit unit) throws InterruptedException {
return queue.poll(timeout, unit);
}
@Override
public int remainingCapacity() {
return queue.remainingCapacity();
}
@Override
public boolean remove(Object o) {
return queue.remove(o);
}
@Override
public boolean contains(Object o) {
return queue.contains(o);
}
@Override
public int drainTo(Collection<? super MessageEvent> c) {
return queue.drainTo(c);
}
@Override
public int drainTo(Collection<? super MessageEvent> c, int maxElements) {
return queue.drainTo(c, maxElements);
}
@Override
public boolean offer(MessageEvent e) {
boolean success = queue.offer(e);
assert success;
int messageSize = getMessageSize(e);
int newWriteBufferSize = writeBufferSize.addAndGet(messageSize);
int highWaterMark = ((NioChannelConfig) getConfig()).getWriteBufferHighWaterMark();
if (newWriteBufferSize >= highWaterMark) {
if (newWriteBufferSize - messageSize < highWaterMark) {
highWaterMarkCounter.incrementAndGet();
if (!notifying.get()) {
notifying.set(Boolean.TRUE);
fireChannelInterestChanged(AbstractNioChannel.this);
notifying.set(Boolean.FALSE);
}
}
}
return true;
}
@Override
public MessageEvent poll() {
MessageEvent e = queue.poll();
if (e != null) {
int messageSize = getMessageSize(e);
int newWriteBufferSize = writeBufferSize.addAndGet(-messageSize);
int lowWaterMark = ((NioChannelConfig) getConfig()).getWriteBufferLowWaterMark();
if (newWriteBufferSize == 0 || newWriteBufferSize < lowWaterMark) {
if (newWriteBufferSize + messageSize >= lowWaterMark) {
highWaterMarkCounter.decrementAndGet();
if (isConnected() && !notifying.get()) {
notifying.set(Boolean.TRUE);
fireChannelInterestChanged(AbstractNioChannel.this);
notifying.set(Boolean.FALSE);
}
}
}
}
return e;
}
private int getMessageSize(MessageEvent e) {
Object m = e.getMessage();
if (m instanceof ChannelBuffer) {
return ((ChannelBuffer) m).readableBytes();
}
return 0;
}
}
private final class WriteTask implements Runnable {
WriteTask() {
}
@Override
public void run() {
writeTaskInTaskQueue.set(false);
worker.writeFromTaskLoop(AbstractNioChannel.this);
}
}
}

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transport/src/main/java/io/netty/channel/socket/nio/AbstractNioWorker.java Normal file
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/*
* 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 static io.netty.channel.Channels.*;
import io.netty.channel.Channel;
import io.netty.channel.ChannelException;
import io.netty.channel.ChannelFuture;
import io.netty.channel.MessageEvent;
import io.netty.channel.socket.nio.SocketSendBufferPool.SendBuffer;
import io.netty.logging.InternalLogger;
import io.netty.logging.InternalLoggerFactory;
import io.netty.util.internal.DeadLockProofWorker;
import io.netty.util.internal.QueueFactory;
import java.io.IOException;
import java.nio.channels.AsynchronousCloseException;
import java.nio.channels.CancelledKeyException;
import java.nio.channels.ClosedChannelException;
import java.nio.channels.NotYetConnectedException;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.WritableByteChannel;
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.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
abstract class AbstractNioWorker implements Runnable {
/**
* Internal Netty logger.
*/
private static final InternalLogger logger = InternalLoggerFactory
.getInstance(AbstractNioWorker.class);
private static final int CONSTRAINT_LEVEL = NioProviderMetadata.CONSTRAINT_LEVEL;
static final int CLEANUP_INTERVAL = 256; // XXX Hard-coded value, but won't need customization.
/**
* Executor used to execute {@link Runnable}s such as
* {@link ChannelRegistionTask}.
*/
private final Executor executor;
/**
* Boolean to indicate if this worker has been started.
*/
private boolean started;
/**
* If this worker has been started thread will be a reference to the thread
* used when starting. i.e. the current thread when the run method is executed.
*/
protected volatile Thread thread;
/**
* The NIO {@link Selector}.
*/
volatile 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();
/**
* Lock for this workers Selector.
*/
private final ReadWriteLock selectorGuard = new ReentrantReadWriteLock();
/**
* Monitor object used to synchronize selector open/close.
*/
private final Object startStopLock = new Object();
/**
* Queue of {@link ChannelRegistionTask}s
*/
private final Queue<Runnable> registerTaskQueue = QueueFactory.createQueue(Runnable.class);
/**
* Queue of WriteTasks
*/
protected final Queue<Runnable> writeTaskQueue = QueueFactory.createQueue(Runnable.class);
private volatile int cancelledKeys; // should use AtomicInteger but we just need approximation
private final SocketSendBufferPool sendBufferPool = new SocketSendBufferPool();
AbstractNioWorker(Executor executor) {
this.executor = executor;
}
void register(AbstractNioChannel<?> channel, ChannelFuture future) {
Runnable registerTask = createRegisterTask(channel, future);
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(executor, this);
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();
}
}
@Override
public void run() {
thread = Thread.currentThread();
boolean shutdown = false;
Selector selector = this.selector;
for (;;) {
wakenUp.set(false);
if (CONSTRAINT_LEVEL != 0) {
selectorGuard.writeLock().lock();
// This empty synchronization block prevents the selector
// from acquiring its lock.
selectorGuard.writeLock().unlock();
}
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;
processRegisterTaskQueue();
processWriteTaskQueue();
processSelectedKeys(selector.selectedKeys());
// 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
// connections are registered in a one-by-one manner instead of
// concurrent manner.
if (selector.keys().isEmpty()) {
if (shutdown ||
executor instanceof ExecutorService && ((ExecutorService) executor).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 that lead to
// excessive CPU consumption.
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// Ignore.
}
}
}
}
private void processRegisterTaskQueue() throws IOException {
for (;;) {
final Runnable task = registerTaskQueue.poll();
if (task == null) {
break;
}
task.run();
cleanUpCancelledKeys();
}
}
private void processWriteTaskQueue() throws IOException {
for (;;) {
final Runnable task = writeTaskQueue.poll();
if (task == null) {
break;
}
task.run();
cleanUpCancelledKeys();
}
}
private void processSelectedKeys(Set<SelectionKey> selectedKeys) throws IOException {
for (Iterator<SelectionKey> i = selectedKeys.iterator(); i.hasNext();) {
SelectionKey k = i.next();
i.remove();
try {
int readyOps = k.readyOps();
if ((readyOps & SelectionKey.OP_READ) != 0 || readyOps == 0) {
if (!read(k)) {
// Connection already closed - no need to handle write.
continue;
}
}
if ((readyOps & SelectionKey.OP_WRITE) != 0) {
writeFromSelectorLoop(k);
}
} catch (CancelledKeyException e) {
close(k);
}
if (cleanUpCancelledKeys()) {
break; // break the loop to avoid ConcurrentModificationException
}
}
}
private boolean cleanUpCancelledKeys() throws IOException {
if (cancelledKeys >= CLEANUP_INTERVAL) {
cancelledKeys = 0;
selector.selectNow();
return true;
}
return false;
}
private void close(SelectionKey k) {
AbstractNioChannel<?> ch = (AbstractNioChannel<?>) k.attachment();
close(ch, succeededFuture(ch));
}
void writeFromUserCode(final AbstractNioChannel<?> channel) {
if (!channel.isConnected()) {
cleanUpWriteBuffer(channel);
return;
}
if (scheduleWriteIfNecessary(channel)) {
return;
}
// From here, we are sure Thread.currentThread() == workerThread.
if (channel.writeSuspended) {
return;
}
if (channel.inWriteNowLoop) {
return;
}
write0(channel);
}
void writeFromTaskLoop(AbstractNioChannel<?> ch) {
if (!ch.writeSuspended) {
write0(ch);
}
}
void writeFromSelectorLoop(final SelectionKey k) {
AbstractNioChannel<?> ch = (AbstractNioChannel<?>) k.attachment();
ch.writeSuspended = false;
write0(ch);
}
protected abstract boolean scheduleWriteIfNecessary(final AbstractNioChannel<?> channel);
private void write0(AbstractNioChannel<?> channel) {
boolean open = true;
boolean addOpWrite = false;
boolean removeOpWrite = false;
long writtenBytes = 0;
final SocketSendBufferPool sendBufferPool = this.sendBufferPool;
final WritableByteChannel ch = channel.channel;
final Queue<MessageEvent> writeBuffer = channel.writeBufferQueue;
final int writeSpinCount = ((NioChannelConfig) channel.getConfig()).getWriteSpinCount();
synchronized (channel.writeLock) {
channel.inWriteNowLoop = true;
for (;;) {
MessageEvent evt = channel.currentWriteEvent;
SendBuffer buf;
if (evt == null) {
if ((channel.currentWriteEvent = evt = writeBuffer.poll()) == null) {
removeOpWrite = true;
channel.writeSuspended = false;
break;
}
channel.currentWriteBuffer = buf = sendBufferPool.acquire(evt.getMessage());
} else {
buf = channel.currentWriteBuffer;
}
ChannelFuture future = evt.getFuture();
try {
long localWrittenBytes = 0;
for (int i = writeSpinCount; i > 0; i --) {
localWrittenBytes = buf.transferTo(ch);
if (localWrittenBytes != 0) {
writtenBytes += localWrittenBytes;
break;
}
if (buf.finished()) {
break;
}
}
if (buf.finished()) {
// Successful write - proceed to the next message.
buf.release();
channel.currentWriteEvent = null;
channel.currentWriteBuffer = null;
evt = null;
buf = null;
future.setSuccess();
} else {
// Not written fully - perhaps the kernel buffer is full.
addOpWrite = true;
channel.writeSuspended = true;
if (localWrittenBytes > 0) {
// Notify progress listeners if necessary.
future.setProgress(
localWrittenBytes,
buf.writtenBytes(), buf.totalBytes());
}
break;
}
} catch (AsynchronousCloseException e) {
// Doesn't need a user attention - ignore.
} catch (Throwable t) {
if (buf != null) {
buf.release();
}
channel.currentWriteEvent = null;
channel.currentWriteBuffer = null;
buf = null;
evt = null;
future.setFailure(t);
fireExceptionCaught(channel, t);
if (t instanceof IOException) {
open = false;
close(channel, succeededFuture(channel));
}
}
}
channel.inWriteNowLoop = false;
// Initially, the following block was executed after releasing
// the writeLock, but there was a race condition, and it has to be
// executed before releasing the writeLock:
//
// https://issues.jboss.org/browse/NETTY-410
//
if (open) {
if (addOpWrite) {
setOpWrite(channel);
} else if (removeOpWrite) {
clearOpWrite(channel);
}
}
}
fireWriteComplete(channel, writtenBytes);
}
private void setOpWrite(AbstractNioChannel<?> channel) {
Selector selector = this.selector;
SelectionKey key = channel.channel.keyFor(selector);
if (key == null) {
return;
}
if (!key.isValid()) {
close(key);
return;
}
// interestOps can change at any time and at any thread.
// Acquire a lock to avoid possible race condition.
synchronized (channel.interestOpsLock) {
int interestOps = channel.getRawInterestOps();
if ((interestOps & SelectionKey.OP_WRITE) == 0) {
interestOps |= SelectionKey.OP_WRITE;
key.interestOps(interestOps);
channel.setRawInterestOpsNow(interestOps);
}
}
}
private void clearOpWrite(AbstractNioChannel<?> channel) {
Selector selector = this.selector;
SelectionKey key = channel.channel.keyFor(selector);
if (key == null) {
return;
}
if (!key.isValid()) {
close(key);
return;
}
// interestOps can change at any time and at any thread.
// Acquire a lock to avoid possible race condition.
synchronized (channel.interestOpsLock) {
int interestOps = channel.getRawInterestOps();
if ((interestOps & SelectionKey.OP_WRITE) != 0) {
interestOps &= ~SelectionKey.OP_WRITE;
key.interestOps(interestOps);
channel.setRawInterestOpsNow(interestOps);
}
}
}
void close(AbstractNioChannel<?> channel, ChannelFuture future) {
boolean connected = channel.isConnected();
boolean bound = channel.isBound();
try {
channel.channel.close();
cancelledKeys ++;
if (channel.setClosed()) {
future.setSuccess();
if (connected) {
fireChannelDisconnected(channel);
}
if (bound) {
fireChannelUnbound(channel);
}
cleanUpWriteBuffer(channel);
fireChannelClosed(channel);
} else {
future.setSuccess();
}
} catch (Throwable t) {
future.setFailure(t);
fireExceptionCaught(channel, t);
}
}
private void cleanUpWriteBuffer(AbstractNioChannel<?> channel) {
Exception cause = null;
boolean fireExceptionCaught = false;
// Clean up the stale messages in the write buffer.
synchronized (channel.writeLock) {
MessageEvent evt = channel.currentWriteEvent;
if (evt != null) {
// Create the exception only once to avoid the excessive overhead
// caused by fillStackTrace.
if (channel.isOpen()) {
cause = new NotYetConnectedException();
} else {
cause = new ClosedChannelException();
}
ChannelFuture future = evt.getFuture();
channel.currentWriteBuffer.release();
channel.currentWriteBuffer = null;
channel.currentWriteEvent = null;
evt = null;
future.setFailure(cause);
fireExceptionCaught = true;
}
Queue<MessageEvent> writeBuffer = channel.writeBufferQueue;
if (!writeBuffer.isEmpty()) {
// Create the exception only once to avoid the excessive overhead
// caused by fillStackTrace.
if (cause == null) {
if (channel.isOpen()) {
cause = new NotYetConnectedException();
} else {
cause = new ClosedChannelException();
}
}
for (;;) {
evt = writeBuffer.poll();
if (evt == null) {
break;
}
evt.getFuture().setFailure(cause);
fireExceptionCaught = true;
}
}
}
if (fireExceptionCaught) {
fireExceptionCaught(channel, cause);
}
}
void setInterestOps(AbstractNioChannel<?> channel, ChannelFuture future, int interestOps) {
boolean changed = false;
try {
// interestOps can change at any time and at any thread.
// Acquire a lock to avoid possible race condition.
synchronized (channel.interestOpsLock) {
Selector selector = this.selector;
SelectionKey key = channel.channel.keyFor(selector);
if (key == null || selector == null) {
// Not registered to the worker yet.
// Set the rawInterestOps immediately; RegisterTask will pick it up.
channel.setRawInterestOpsNow(interestOps);
return;
}
// Override OP_WRITE flag - a user cannot change this flag.
interestOps &= ~Channel.OP_WRITE;
interestOps |= channel.getRawInterestOps() & Channel.OP_WRITE;
switch (CONSTRAINT_LEVEL) {
case 0:
if (channel.getRawInterestOps() != interestOps) {
key.interestOps(interestOps);
if (Thread.currentThread() != thread &&
wakenUp.compareAndSet(false, true)) {
selector.wakeup();
}
changed = true;
}
break;
case 1:
case 2:
if (channel.getRawInterestOps() != interestOps) {
if (Thread.currentThread() == thread) {
key.interestOps(interestOps);
changed = true;
} else {
selectorGuard.readLock().lock();
try {
if (wakenUp.compareAndSet(false, true)) {
selector.wakeup();
}
key.interestOps(interestOps);
changed = true;
} finally {
selectorGuard.readLock().unlock();
}
}
}
break;
default:
throw new Error();
}
if (changed) {
channel.setRawInterestOpsNow(interestOps);
}
}
future.setSuccess();
if (changed) {
fireChannelInterestChanged(channel);
}
} catch (CancelledKeyException e) {
// setInterestOps() was called on a closed channel.
ClosedChannelException cce = new ClosedChannelException();
future.setFailure(cce);
fireExceptionCaught(channel, cce);
} catch (Throwable t) {
future.setFailure(t);
fireExceptionCaught(channel, t);
}
}
/**
* Read is called when a Selector has been notified that the underlying channel
* was something to be read. The channel would previously have registered its interest
* in read operations.
*
* @param key The selection key which contains the Selector registration information.
*/
protected abstract boolean read(SelectionKey k);
/**
* Create a new {@link Runnable} which will register the {@link AbstractNioWorker} with the {@link Channel}
*
* @param channel
* @param future
* @return task
*/
protected abstract Runnable createRegisterTask(AbstractNioChannel<?> channel, ChannelFuture future);
}

149
transport/src/main/java/io/netty/channel/socket/nio/AbstractWriteRequestQueue.java
View File

@ -1,149 +0,0 @@
/*
* 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 java.util.Collection;
import java.util.Iterator;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.TimeUnit;
import io.netty.channel.MessageEvent;
import io.netty.util.internal.QueueFactory;
abstract class AbstractWriteRequestQueue implements BlockingQueue<MessageEvent> {
protected final BlockingQueue<MessageEvent> queue;
public AbstractWriteRequestQueue() {
this.queue = QueueFactory.createQueue(MessageEvent.class);
}
@Override
public MessageEvent remove() {
return queue.remove();
}
@Override
public MessageEvent element() {
return queue.element();
}
@Override
public MessageEvent peek() {
return queue.peek();
}
@Override
public int size() {
return queue.size();
}
@Override
public boolean isEmpty() {
return queue.isEmpty();
}
@Override
public Iterator<MessageEvent> iterator() {
return queue.iterator();
}
@Override
public Object[] toArray() {
return queue.toArray();
}
@Override
public <T> T[] toArray(T[] a) {
return queue.toArray(a);
}
@Override
public boolean containsAll(Collection<?> c) {
return queue.containsAll(c);
}
@Override
public boolean addAll(Collection<? extends MessageEvent> c) {
return queue.addAll(c);
}
@Override
public boolean removeAll(Collection<?> c) {
return queue.removeAll(c);
}
@Override
public boolean retainAll(Collection<?> c) {
return queue.retainAll(c);
}
@Override
public void clear() {
queue.clear();
}
@Override
public boolean add(MessageEvent e) {
return queue.add(e);
}
@Override
public void put(MessageEvent e) throws InterruptedException {
queue.put(e);
}
@Override
public boolean offer(MessageEvent e, long timeout, TimeUnit unit) throws InterruptedException {
return queue.offer(e, timeout, unit);
}
@Override
public MessageEvent take() throws InterruptedException {
return queue.take();
}
@Override
public MessageEvent poll(long timeout, TimeUnit unit) throws InterruptedException {
return queue.poll(timeout, unit);
}
@Override
public int remainingCapacity() {
return queue.remainingCapacity();
}
@Override
public boolean remove(Object o) {
return queue.remove(o);
}
@Override
public boolean contains(Object o) {
return queue.contains(o);
}
@Override
public int drainTo(Collection<? super MessageEvent> c) {
return queue.drainTo(c);
}
@Override
public int drainTo(Collection<? super MessageEvent> c, int maxElements) {
return queue.drainTo(c, maxElements);
}
}

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

@ -25,7 +25,7 @@ import io.netty.channel.ChannelConfig;
* Special {@link ChannelConfig} sub-type which offers extra methods which are useful for NIO.
*
*/
public interface NioChannelConfig extends ChannelConfig{
public interface NioChannelConfig extends ChannelConfig {
/**
* Returns the high water mark of the write buffer. If the number of bytes

10
transport/src/main/java/io/netty/channel/socket/nio/NioClientSocketPipelineSink.java
View File

@ -113,7 +113,7 @@ class NioClientSocketPipelineSink extends AbstractChannelSink {
} else if (e instanceof MessageEvent) {
MessageEvent event = (MessageEvent) e;
NioSocketChannel channel = (NioSocketChannel) event.getChannel();
boolean offered = channel.writeBuffer.offer(event);
boolean offered = channel.writeBufferQueue.offer(event);
assert offered;
channel.worker.writeFromUserCode(channel);
}
@ -123,7 +123,7 @@ class NioClientSocketPipelineSink extends AbstractChannelSink {
NioClientSocketChannel channel, ChannelFuture future,
SocketAddress localAddress) {
try {
channel.socket.socket().bind(localAddress);
channel.channel.socket().bind(localAddress);
channel.boundManually = true;
channel.setBound();
future.setSuccess();
@ -138,7 +138,7 @@ class NioClientSocketPipelineSink extends AbstractChannelSink {
final NioClientSocketChannel channel, final ChannelFuture cf,
SocketAddress remoteAddress) {
try {
if (channel.socket.connect(remoteAddress)) {
if (channel.channel.connect(remoteAddress)) {
channel.worker.register(channel, cf);
} else {
channel.getCloseFuture().addListener(new ChannelFutureListener() {
@ -392,7 +392,7 @@ class NioClientSocketPipelineSink extends AbstractChannelSink {
private void connect(SelectionKey k) {
NioClientSocketChannel ch = (NioClientSocketChannel) k.attachment();
try {
if (ch.socket.finishConnect()) {
if (ch.channel.finishConnect()) {
k.cancel();
ch.worker.register(ch, ch.connectFuture);
}
@ -422,7 +422,7 @@ class NioClientSocketPipelineSink extends AbstractChannelSink {
@Override
public void run() {
try {
channel.socket.register(
channel.channel.register(
boss.selector, SelectionKey.OP_CONNECT, channel);
} catch (ClosedChannelException e) {
channel.worker.close(channel, succeededFuture(channel));

275
transport/src/main/java/io/netty/channel/socket/nio/NioDatagramChannel.java
View File

@ -15,36 +15,23 @@
*/
package io.netty.channel.socket.nio;
import static io.netty.channel.Channels.*;
import static io.netty.channel.Channels.fireChannelOpen;
import io.netty.channel.ChannelException;
import io.netty.channel.ChannelFactory;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.ChannelSink;
import io.netty.channel.socket.DatagramChannelConfig;
import java.io.IOException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.NetworkInterface;
import java.net.SocketAddress;
import java.nio.channels.DatagramChannel;
import java.util.Queue;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import io.netty.buffer.ChannelBuffer;
import io.netty.channel.AbstractChannel;
import io.netty.channel.Channel;
import io.netty.channel.ChannelException;
import io.netty.channel.ChannelFactory;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.ChannelSink;
import io.netty.channel.MessageEvent;
import io.netty.channel.socket.DatagramChannelConfig;
import io.netty.channel.socket.nio.SocketSendBufferPool.SendBuffer;
import io.netty.util.internal.LegacyLinkedTransferQueue;
import io.netty.util.internal.ThreadLocalBoolean;
/**
* Provides an NIO based {@link io.netty.channel.socket.DatagramChannel}.
*/
final class NioDatagramChannel extends AbstractChannel
final class NioDatagramChannel extends AbstractNioChannel<DatagramChannel>
implements io.netty.channel.socket.DatagramChannel {
/**
@ -52,67 +39,7 @@ final class NioDatagramChannel extends AbstractChannel
*/
private final NioDatagramChannelConfig config;
/**
* The {@link NioDatagramWorker} for this NioDatagramChannnel.
*/
final NioDatagramWorker worker;
/**
* The {@link DatagramChannel} that this channel uses.
*/
private final java.nio.channels.DatagramChannel datagramChannel;
/**
* Monitor object to synchronize access to InterestedOps.
*/
final Object interestOpsLock = new Object();
/**
* Monitor object for synchronizing access to the {@link WriteRequestQueue}.
*/
final Object writeLock = new Object();
/**
* WriteTask that performs write operations.
*/
final Runnable writeTask = new WriteTask();
/**
* Indicates if there is a {@link WriteTask} in the task queue.
*/
final AtomicBoolean writeTaskInTaskQueue = new AtomicBoolean();
/**
* Queue of write {@link MessageEvent}s.
*/
final Queue<MessageEvent> writeBufferQueue = new WriteRequestQueue();
/**
* Keeps track of the number of bytes that the {@link WriteRequestQueue} currently
* contains.
*/
final AtomicInteger writeBufferSize = new AtomicInteger();
/**
* Keeps track of the highWaterMark.
*/
final AtomicInteger highWaterMarkCounter = new AtomicInteger();
/**
* The current write {@link MessageEvent}
*/
MessageEvent currentWriteEvent;
SendBuffer currentWriteBuffer;
/**
* Boolean that indicates that write operation is in progress.
*/
boolean inWriteNowLoop;
boolean writeSuspended;
private volatile InetSocketAddress localAddress;
volatile InetSocketAddress remoteAddress;
static NioDatagramChannel create(ChannelFactory factory,
ChannelPipeline pipeline, ChannelSink sink, NioDatagramWorker worker) {
NioDatagramChannel instance =
@ -124,13 +51,11 @@ final class NioDatagramChannel extends AbstractChannel
private NioDatagramChannel(final ChannelFactory factory,
final ChannelPipeline pipeline, final ChannelSink sink,
final NioDatagramWorker worker) {
super(null, factory, pipeline, sink);
this.worker = worker;
datagramChannel = openNonBlockingChannel();
config = new DefaultNioDatagramChannelConfig(datagramChannel.socket());
super(null, factory, pipeline, sink, worker, openNonBlockingChannel());
config = new DefaultNioDatagramChannelConfig(channel.socket());
}
private DatagramChannel openNonBlockingChannel() {
private static DatagramChannel openNonBlockingChannel() {
try {
final DatagramChannel channel = DatagramChannel.open();
channel.configureBlocking(false);
@ -140,44 +65,15 @@ final class NioDatagramChannel extends AbstractChannel
}
}
@Override
public InetSocketAddress getLocalAddress() {
InetSocketAddress localAddress = this.localAddress;
if (localAddress == null) {
try {
this.localAddress = localAddress =
(InetSocketAddress) datagramChannel.socket().getLocalSocketAddress();
} catch (Throwable t) {
// Sometimes fails on a closed socket in Windows.
return null;
}
}
return localAddress;
}
@Override
public InetSocketAddress getRemoteAddress() {
InetSocketAddress remoteAddress = this.remoteAddress;
if (remoteAddress == null) {
try {
this.remoteAddress = remoteAddress =
(InetSocketAddress) datagramChannel.socket().getRemoteSocketAddress();
} catch (Throwable t) {
// Sometimes fails on a closed socket in Windows.
return null;
}
}
return remoteAddress;
}
@Override
public boolean isBound() {
return isOpen() && datagramChannel.socket().isBound();
return isOpen() && channel.socket().isBound();
}
@Override
public boolean isConnected() {
return datagramChannel.isConnected();
return channel.isConnected();
}
@Override
@ -191,140 +87,7 @@ final class NioDatagramChannel extends AbstractChannel
}
DatagramChannel getDatagramChannel() {
return datagramChannel;
}
@Override
public int getInterestOps() {
if (!isOpen()) {
return Channel.OP_WRITE;
}
int interestOps = getRawInterestOps();
int writeBufferSize = this.writeBufferSize.get();
if (writeBufferSize != 0) {
if (highWaterMarkCounter.get() > 0) {
int lowWaterMark = getConfig().getWriteBufferLowWaterMark();
if (writeBufferSize >= lowWaterMark) {
interestOps |= Channel.OP_WRITE;
} else {
interestOps &= ~Channel.OP_WRITE;
}
} else {
int highWaterMark = getConfig().getWriteBufferHighWaterMark();
if (writeBufferSize >= highWaterMark) {
interestOps |= Channel.OP_WRITE;
} else {
interestOps &= ~Channel.OP_WRITE;
}
}
} else {
interestOps &= ~Channel.OP_WRITE;
}
return interestOps;
}
int getRawInterestOps() {
return super.getInterestOps();
}
void setRawInterestOpsNow(int interestOps) {
super.setInterestOpsNow(interestOps);
}
@Override
public ChannelFuture write(Object message, SocketAddress remoteAddress) {
if (remoteAddress == null || remoteAddress.equals(getRemoteAddress())) {
return super.write(message, null);
} else {
return super.write(message, remoteAddress);
}
}
/**
* {@link WriteRequestQueue} is an extension of {@link AbstractWriteRequestQueue}
* that adds support for highWaterMark checking of the write buffer size.
*/
private final class WriteRequestQueue extends
AbstractWriteRequestQueue {
private final ThreadLocalBoolean notifying = new ThreadLocalBoolean();
/**
* This method first delegates to {@link LegacyLinkedTransferQueue#offer(Object)} and
* adds support for keeping track of the size of the this write buffer.
*/
@Override
public boolean offer(MessageEvent e) {
boolean success = queue.offer(e);
assert success;
int messageSize = getMessageSize(e);
int newWriteBufferSize = writeBufferSize.addAndGet(messageSize);
int highWaterMark = getConfig().getWriteBufferHighWaterMark();
if (newWriteBufferSize >= highWaterMark) {
if (newWriteBufferSize - messageSize < highWaterMark) {
highWaterMarkCounter.incrementAndGet();
if (!notifying.get()) {
notifying.set(Boolean.TRUE);
fireChannelInterestChanged(NioDatagramChannel.this);
notifying.set(Boolean.FALSE);
}
}
}
return true;
}
/**
* This method first delegates to {@link LegacyLinkedTransferQueue#poll()} and
* adds support for keeping track of the size of the this writebuffers queue.
*/
@Override
public MessageEvent poll() {
MessageEvent e = queue.poll();
if (e != null) {
int messageSize = getMessageSize(e);
int newWriteBufferSize = writeBufferSize.addAndGet(-messageSize);
int lowWaterMark = getConfig().getWriteBufferLowWaterMark();
if (newWriteBufferSize == 0 || newWriteBufferSize < lowWaterMark) {
if (newWriteBufferSize + messageSize >= lowWaterMark) {
highWaterMarkCounter.decrementAndGet();
if (isBound() && !notifying.get()) {
notifying.set(Boolean.TRUE);
fireChannelInterestChanged(NioDatagramChannel.this);
notifying.set(Boolean.FALSE);
}
}
}
}
return e;
}
private int getMessageSize(MessageEvent e) {
Object m = e.getMessage();
if (m instanceof ChannelBuffer) {
return ((ChannelBuffer) m).readableBytes();
}
return 0;
}
}
/**
* WriteTask is a simple runnable performs writes by delegating the {@link NioDatagramWorker}.
*/
private final class WriteTask implements Runnable {
WriteTask() {
}
@Override
public void run() {
writeTaskInTaskQueue.set(false);
worker.writeFromTaskLoop(NioDatagramChannel.this);
}
return channel;
}
@Override
@ -348,4 +111,14 @@ final class NioDatagramChannel extends AbstractChannel
NetworkInterface networkInterface) {
throw new UnsupportedOperationException();
}
@Override
InetSocketAddress getLocalSocketAddress() throws Exception {
return (InetSocketAddress) channel.socket().getLocalSocketAddress();
}
@Override
InetSocketAddress getRemoteSocketAddress() throws Exception {
return (InetSocketAddress) channel.socket().getRemoteSocketAddress();
}
}

705
transport/src/main/java/io/netty/channel/socket/nio/NioDatagramWorker.java
View File

@ -15,102 +15,28 @@
*/
package io.netty.channel.socket.nio;
import static io.netty.channel.Channels.*;
import java.io.IOException;
import java.net.SocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.AsynchronousCloseException;
import java.nio.channels.CancelledKeyException;
import java.nio.channels.ClosedChannelException;
import java.nio.channels.DatagramChannel;
import java.nio.channels.NotYetBoundException;
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.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import static io.netty.channel.Channels.fireChannelDisconnected;
import static io.netty.channel.Channels.fireExceptionCaught;
import static io.netty.channel.Channels.fireMessageReceived;
import static io.netty.channel.Channels.succeededFuture;
import io.netty.buffer.ChannelBufferFactory;
import io.netty.channel.Channel;
import io.netty.channel.ChannelException;
import io.netty.channel.ChannelFuture;
import io.netty.channel.MessageEvent;
import io.netty.channel.ReceiveBufferSizePredictor;
import io.netty.channel.socket.nio.SocketSendBufferPool.SendBuffer;
import io.netty.logging.InternalLogger;
import io.netty.logging.InternalLoggerFactory;
import io.netty.util.internal.QueueFactory;
import java.net.SocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.ClosedChannelException;
import java.nio.channels.DatagramChannel;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.util.concurrent.Executor;
/**
* A class responsible for registering channels with {@link Selector}.
* It also implements the {@link Selector} loop.
*/
class NioDatagramWorker implements Runnable {
/**
* Internal Netty logger.
*/
private static final InternalLogger logger = InternalLoggerFactory
.getInstance(NioDatagramWorker.class);
/**
* Executor used to execute {@link Runnable}s such as
* {@link ChannelRegistionTask}.
*/
private final Executor executor;
/**
* Boolean to indicate if this worker has been started.
*/
private boolean started;
/**
* If this worker has been started thread will be a reference to the thread
* used when starting. i.e. the current thread when the run method is executed.
*/
private volatile Thread thread;
/**
* The NIO {@link Selector}.
*/
volatile 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.
*/
private final AtomicBoolean wakenUp = new AtomicBoolean();
/**
* Lock for this workers Selector.
*/
private final ReadWriteLock selectorGuard = new ReentrantReadWriteLock();
/**
* Monitor object used to synchronize selector open/close.
*/
private final Object startStopLock = new Object();
/**
* Queue of {@link ChannelRegistionTask}s
*/
private final Queue<Runnable> registerTaskQueue = QueueFactory.createQueue(Runnable.class);
/**
* Queue of WriteTasks
*/
private final Queue<Runnable> writeTaskQueue = QueueFactory.createQueue(Runnable.class);
private volatile int cancelledKeys; // should use AtomicInteger but we just need approximation
private final SocketSendBufferPool sendBufferPool = new SocketSendBufferPool();
class NioDatagramWorker extends AbstractNioWorker {
/**
* Sole constructor.
@ -119,246 +45,13 @@ class NioDatagramWorker implements Runnable {
* such as {@link ChannelRegistionTask}
*/
NioDatagramWorker(final Executor executor) {
this.executor = executor;
super(executor);
}
/**
* Registers the passed-in channel with a selector.
*
* @param channel the channel to register
* @param future the {@link ChannelFuture} that has to be notified on
* completion
*/
void register(final NioDatagramChannel channel, final ChannelFuture future) {
final Runnable channelRegTask = new ChannelRegistionTask(channel,
future);
Selector selector;
synchronized (startStopLock) {
if (!started) {
// Open a selector if this worker didn't start yet.
try {
this.selector = selector = Selector.open();
} catch (final Throwable t) {
throw new ChannelException("Failed to create a selector.",
t);
}
boolean success = false;
try {
// Start the main selector loop. See run() for details.
executor.execute(this);
success = true;
} finally {
if (!success) {
try {
// Release the Selector if the execution fails.
selector.close();
} catch (final 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;
// "Add" the registration task to the register task queue.
boolean offered = registerTaskQueue.offer(channelRegTask);
assert offered;
}
if (wakenUp.compareAndSet(false, true)) {
selector.wakeup();
}
}
/**
* Selector loop.
*/
@Override
public void run() {
// Store a ref to the current thread.
thread = Thread.currentThread();
final Selector selector = this.selector;
boolean shutdown = false;
for (;;) {
wakenUp.set(false);
if (NioProviderMetadata.CONSTRAINT_LEVEL != 0) {
selectorGuard.writeLock().lock();
// This empty synchronization block prevents the selector from acquiring its lock.
selectorGuard.writeLock().unlock();
}
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;
processRegisterTaskQueue();
processWriteTaskQueue();
processSelectedKeys(selector.selectedKeys());
// Exit the loop when there's nothing to handle (the registered
// key set is empty.
// The shutdown flag is used to delay the shutdown of this
// loop to avoid excessive Selector creation when
// connections are registered in a one-by-one manner instead of
// concurrent manner.
if (selector.keys().isEmpty()) {
if (shutdown || executor instanceof ExecutorService &&
((ExecutorService) executor).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 that lead to
// excessive CPU consumption.
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// Ignore.
}
}
}
}
/**
* Will go through all the {@link ChannelRegistionTask}s in the
* task queue and run them (registering them).
*/
private void processRegisterTaskQueue() throws IOException {
for (;;) {
final Runnable task = registerTaskQueue.poll();
if (task == null) {
break;
}
task.run();
cleanUpCancelledKeys();
}
}
/**
* Will go through all the WriteTasks and run them.
*/
private void processWriteTaskQueue() throws IOException {
for (;;) {
final Runnable task = writeTaskQueue.poll();
if (task == null) {
break;
}
task.run();
cleanUpCancelledKeys();
}
}
private void processSelectedKeys(final Set<SelectionKey> selectedKeys) throws IOException {
for (Iterator<SelectionKey> i = selectedKeys.iterator(); i.hasNext();) {
SelectionKey k = i.next();
i.remove();
try {
int readyOps = k.readyOps();
if ((readyOps & SelectionKey.OP_READ) != 0 || readyOps == 0) {
if (!read(k)) {
// Connection already closed - no need to handle write.
continue;
}
}
if ((readyOps & SelectionKey.OP_WRITE) != 0) {
writeFromSelectorLoop(k);
}
} catch (CancelledKeyException e) {
close(k);
}
if (cleanUpCancelledKeys()) {
break; // Break the loop to avoid ConcurrentModificationException
}
}
}
private boolean cleanUpCancelledKeys() throws IOException {
if (cancelledKeys >= NioWorker.CLEANUP_INTERVAL) {
cancelledKeys = 0;
selector.selectNow();
return true;
}
return false;
}
/**
* Read is called when a Selector has been notified that the underlying channel
* was something to be read. The channel would previously have registered its interest
* in read operations.
*
* @param key The selection key which contains the Selector registration information.
*/
private boolean read(final SelectionKey key) {
protected boolean read(final SelectionKey key) {
final NioDatagramChannel channel = (NioDatagramChannel) key.attachment();
ReceiveBufferSizePredictor predictor =
channel.getConfig().getReceiveBufferSizePredictor();
@ -408,53 +101,10 @@ class NioDatagramWorker implements Runnable {
return true;
}
private void close(SelectionKey k) {
final NioDatagramChannel ch = (NioDatagramChannel) k.attachment();
close(ch, succeededFuture(ch));
}
void writeFromUserCode(final NioDatagramChannel channel) {
/*
* Note that we are not checking if the channel is connected. Connected
* has a different meaning in UDP and means that the channels socket is
* configured to only send and receive from a given remote peer.
*/
if (!channel.isBound()) {
cleanUpWriteBuffer(channel);
return;
}
if (scheduleWriteIfNecessary(channel)) {
return;
}
// From here, we are sure Thread.currentThread() == workerThread.
if (channel.writeSuspended) {
return;
}
if (channel.inWriteNowLoop) {
return;
}
write0(channel);
}
void writeFromTaskLoop(final NioDatagramChannel ch) {
if (!ch.writeSuspended) {
write0(ch);
}
}
void writeFromSelectorLoop(final SelectionKey k) {
NioDatagramChannel ch = (NioDatagramChannel) k.attachment();
ch.writeSuspended = false;
write0(ch);
}
private boolean scheduleWriteIfNecessary(final NioDatagramChannel channel) {
@Override
protected boolean scheduleWriteIfNecessary(final AbstractNioChannel<?> channel) {
final Thread workerThread = thread;
if (workerThread == null || Thread.currentThread() != workerThread) {
if (channel.writeTaskInTaskQueue.compareAndSet(false, true)) {
@ -475,155 +125,6 @@ class NioDatagramWorker implements Runnable {
return false;
}
private void write0(final NioDatagramChannel channel) {
boolean addOpWrite = false;
boolean removeOpWrite = false;
long writtenBytes = 0;
final SocketSendBufferPool sendBufferPool = this.sendBufferPool;
final DatagramChannel ch = channel.getDatagramChannel();
final Queue<MessageEvent> writeBuffer = channel.writeBufferQueue;
final int writeSpinCount = channel.getConfig().getWriteSpinCount();
synchronized (channel.writeLock) {
// inform the channel that write is in-progress
channel.inWriteNowLoop = true;
// loop forever...
for (;;) {
MessageEvent evt = channel.currentWriteEvent;
SendBuffer buf;
if (evt == null) {
if ((channel.currentWriteEvent = evt = writeBuffer.poll()) == null) {
removeOpWrite = true;
channel.writeSuspended = false;
break;
}
channel.currentWriteBuffer = buf = sendBufferPool.acquire(evt.getMessage());
} else {
buf = channel.currentWriteBuffer;
}
try {
long localWrittenBytes = 0;
SocketAddress raddr = evt.getRemoteAddress();
if (raddr == null) {
for (int i = writeSpinCount; i > 0; i --) {
localWrittenBytes = buf.transferTo(ch);
if (localWrittenBytes != 0) {
writtenBytes += localWrittenBytes;
break;
}
if (buf.finished()) {
break;
}
}
} else {
for (int i = writeSpinCount; i > 0; i --) {
localWrittenBytes = buf.transferTo(ch, raddr);
if (localWrittenBytes != 0) {
writtenBytes += localWrittenBytes;
break;
}
if (buf.finished()) {
break;
}
}
}
if (localWrittenBytes > 0 || buf.finished()) {
// Successful write - proceed to the next message.
buf.release();
ChannelFuture future = evt.getFuture();
channel.currentWriteEvent = null;
channel.currentWriteBuffer = null;
evt = null;
buf = null;
future.setSuccess();
} else {
// Not written at all - perhaps the kernel buffer is full.
addOpWrite = true;
channel.writeSuspended = true;
break;
}
} catch (final AsynchronousCloseException e) {
// Doesn't need a user attention - ignore.
} catch (final Throwable t) {
buf.release();
ChannelFuture future = evt.getFuture();
channel.currentWriteEvent = null;
channel.currentWriteBuffer = null;
buf = null;
evt = null;
future.setFailure(t);
fireExceptionCaught(channel, t);
}
}
channel.inWriteNowLoop = false;
// Initially, the following block was executed after releasing
// the writeLock, but there was a race condition, and it has to be
// executed before releasing the writeLock:
//
// https://issues.jboss.org/browse/NETTY-410
//
if (addOpWrite) {
setOpWrite(channel);
} else if (removeOpWrite) {
clearOpWrite(channel);
}
}
fireWriteComplete(channel, writtenBytes);
}
private void setOpWrite(final NioDatagramChannel channel) {
Selector selector = this.selector;
SelectionKey key = channel.getDatagramChannel().keyFor(selector);
if (key == null) {
return;
}
if (!key.isValid()) {
close(key);
return;
}
// interestOps can change at any time and at any thread.
// Acquire a lock to avoid possible race condition.
synchronized (channel.interestOpsLock) {
int interestOps = channel.getRawInterestOps();
if ((interestOps & SelectionKey.OP_WRITE) == 0) {
interestOps |= SelectionKey.OP_WRITE;
key.interestOps(interestOps);
channel.setRawInterestOpsNow(interestOps);
}
}
}
private void clearOpWrite(NioDatagramChannel channel) {
Selector selector = this.selector;
SelectionKey key = channel.getDatagramChannel().keyFor(selector);
if (key == null) {
return;
}
if (!key.isValid()) {
close(key);
return;
}
// interestOps can change at any time and at any thread.
// Acquire a lock to avoid possible race condition.
synchronized (channel.interestOpsLock) {
int interestOps = channel.getRawInterestOps();
if ((interestOps & SelectionKey.OP_WRITE) != 0) {
interestOps &= ~SelectionKey.OP_WRITE;
key.interestOps(interestOps);
channel.setRawInterestOpsNow(interestOps);
}
}
}
static void disconnect(NioDatagramChannel channel, ChannelFuture future) {
boolean connected = channel.isConnected();
@ -639,171 +140,12 @@ class NioDatagramWorker implements Runnable {
}
}
void close(final NioDatagramChannel channel,
final ChannelFuture future) {
boolean connected = channel.isConnected();
boolean bound = channel.isBound();
try {
channel.getDatagramChannel().close();
cancelledKeys ++;
if (channel.setClosed()) {
future.setSuccess();
if (connected) {
fireChannelDisconnected(channel);
}
if (bound) {
fireChannelUnbound(channel);
}
cleanUpWriteBuffer(channel);
fireChannelClosed(channel);
} else {
future.setSuccess();
}
} catch (Throwable t) {
future.setFailure(t);
fireExceptionCaught(channel, t);
}
@Override
protected Runnable createRegisterTask(AbstractNioChannel<?> channel, ChannelFuture future) {
return new ChannelRegistionTask((NioDatagramChannel) channel, future);
}
private void cleanUpWriteBuffer(final NioDatagramChannel channel) {
Exception cause = null;
boolean fireExceptionCaught = false;
// Clean up the stale messages in the write buffer.
synchronized (channel.writeLock) {
MessageEvent evt = channel.currentWriteEvent;
if (evt != null) {
// Create the exception only once to avoid the excessive overhead
// caused by fillStackTrace.
if (channel.isOpen()) {
cause = new NotYetBoundException();
} else {
cause = new ClosedChannelException();
}
ChannelFuture future = evt.getFuture();
channel.currentWriteBuffer.release();
channel.currentWriteBuffer = null;
channel.currentWriteEvent = null;
evt = null;
future.setFailure(cause);
fireExceptionCaught = true;
}
Queue<MessageEvent> writeBuffer = channel.writeBufferQueue;
if (!writeBuffer.isEmpty()) {
// Create the exception only once to avoid the excessive overhead
// caused by fillStackTrace.
if (cause == null) {
if (channel.isOpen()) {
cause = new NotYetBoundException();
} else {
cause = new ClosedChannelException();
}
}
for (;;) {
evt = writeBuffer.poll();
if (evt == null) {
break;
}
evt.getFuture().setFailure(cause);
fireExceptionCaught = true;
}
}
}
if (fireExceptionCaught) {
fireExceptionCaught(channel, cause);
}
}
void setInterestOps(final NioDatagramChannel channel,
ChannelFuture future, int interestOps) {
boolean changed = false;
try {
// interestOps can change at any time and by any thread.
// Acquire a lock to avoid possible race condition.
synchronized (channel.interestOpsLock) {
final Selector selector = this.selector;
final SelectionKey key = channel.getDatagramChannel().keyFor(selector);
if (key == null || selector == null) {
// Not registered to the worker yet.
// Set the rawInterestOps immediately; RegisterTask will pick it up.
channel.setRawInterestOpsNow(interestOps);
return;
}
// Override OP_WRITE flag - a user cannot change this flag.
interestOps &= ~Channel.OP_WRITE;
interestOps |= channel.getRawInterestOps() & Channel.OP_WRITE;
switch (NioProviderMetadata.CONSTRAINT_LEVEL) {
case 0:
if (channel.getRawInterestOps() != interestOps) {
// Set the interesteOps on the SelectionKey
key.interestOps(interestOps);
// If the worker thread (the one that that might possibly be blocked
// in a select() call) is not the thread executing this method wakeup
// the select() operation.
if (Thread.currentThread() != thread &&
wakenUp.compareAndSet(false, true)) {
selector.wakeup();
}
changed = true;
}
break;
case 1:
case 2:
if (channel.getRawInterestOps() != interestOps) {
if (Thread.currentThread() == thread) {
// Going to set the interestOps from the same thread.
// Set the interesteOps on the SelectionKey
key.interestOps(interestOps);
changed = true;
} else {
// Going to set the interestOps from a different thread
// and some old provides will need synchronization.
selectorGuard.readLock().lock();
try {
if (wakenUp.compareAndSet(false, true)) {
selector.wakeup();
}
key.interestOps(interestOps);
changed = true;
} finally {
selectorGuard.readLock().unlock();
}
}
}
break;
default:
throw new Error();
}
if (changed) {
channel.setRawInterestOpsNow(interestOps);
}
}
future.setSuccess();
if (changed) {
fireChannelInterestChanged(channel);
}
} catch (final CancelledKeyException e) {
// setInterestOps() was called on a closed channel.
ClosedChannelException cce = new ClosedChannelException();
future.setFailure(cce);
fireExceptionCaught(channel, cce);
} catch (final Throwable t) {
future.setFailure(t);
fireExceptionCaught(channel, t);
}
}
/**
* RegisterTask is a task responsible for registering a channel with a
* selector.
@ -852,4 +194,5 @@ class NioDatagramWorker implements Runnable {
}
}
}
}

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

@ -122,7 +122,7 @@ class NioServerSocketPipelineSink extends AbstractChannelSink {
} else if (e instanceof MessageEvent) {
MessageEvent event = (MessageEvent) e;
NioSocketChannel channel = (NioSocketChannel) event.getChannel();
boolean offered = channel.writeBuffer.offer(event);
boolean offered = channel.writeBufferQueue.offer(event);
assert offered;
channel.worker.writeFromUserCode(channel);
}

192
transport/src/main/java/io/netty/channel/socket/nio/NioSocketChannel.java
View File

@ -15,27 +15,15 @@
*/
package io.netty.channel.socket.nio;
import static io.netty.channel.Channels.*;
import java.net.InetSocketAddress;
import java.net.SocketAddress;
import java.nio.channels.SocketChannel;
import java.util.Queue;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import io.netty.buffer.ChannelBuffer;
import io.netty.channel.AbstractChannel;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFactory;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.ChannelSink;
import io.netty.channel.MessageEvent;
import io.netty.channel.socket.nio.SocketSendBufferPool.SendBuffer;
import io.netty.util.internal.ThreadLocalBoolean;
class NioSocketChannel extends AbstractChannel
import java.net.InetSocketAddress;
import java.nio.channels.SocketChannel;
class NioSocketChannel extends AbstractNioChannel<SocketChannel>
implements io.netty.channel.socket.SocketChannel {
private static final int ST_OPEN = 0;
@ -44,35 +32,14 @@ class NioSocketChannel extends AbstractChannel
private static final int ST_CLOSED = -1;
volatile int state = ST_OPEN;
final SocketChannel socket;
final NioWorker worker;
private final NioSocketChannelConfig config;
private volatile InetSocketAddress localAddress;
private volatile InetSocketAddress remoteAddress;
final Object interestOpsLock = new Object();
final Object writeLock = new Object();
final Runnable writeTask = new WriteTask();
final AtomicBoolean writeTaskInTaskQueue = new AtomicBoolean();
final Queue<MessageEvent> writeBuffer = new WriteRequestQueue();
final AtomicInteger writeBufferSize = new AtomicInteger();
final AtomicInteger highWaterMarkCounter = new AtomicInteger();
boolean inWriteNowLoop;
boolean writeSuspended;
MessageEvent currentWriteEvent;
SendBuffer currentWriteBuffer;
public NioSocketChannel(
Channel parent, ChannelFactory factory,
ChannelPipeline pipeline, ChannelSink sink,
SocketChannel socket, NioWorker worker) {
super(parent, factory, pipeline, sink);
super(parent, factory, pipeline, sink, worker, socket);
this.socket = socket;
this.worker = worker;
config = new DefaultNioSocketChannelConfig(socket.socket());
}
@ -81,36 +48,6 @@ class NioSocketChannel extends AbstractChannel
return config;
}
@Override
public InetSocketAddress getLocalAddress() {
InetSocketAddress localAddress = this.localAddress;
if (localAddress == null) {
try {
this.localAddress = localAddress =
(InetSocketAddress) socket.socket().getLocalSocketAddress();
} catch (Throwable t) {
// Sometimes fails on a closed socket in Windows.
return null;
}
}
return localAddress;
}
@Override
public InetSocketAddress getRemoteAddress() {
InetSocketAddress remoteAddress = this.remoteAddress;
if (remoteAddress == null) {
try {
this.remoteAddress = remoteAddress =
(InetSocketAddress) socket.socket().getRemoteSocketAddress();
} catch (Throwable t) {
// Sometimes fails on a closed socket in Windows.
return null;
}
}
return remoteAddress;
}
@Override
public boolean isOpen() {
return state >= ST_OPEN;
@ -143,123 +80,14 @@ class NioSocketChannel extends AbstractChannel
return super.setClosed();
}
@Override
public int getInterestOps() {
if (!isOpen()) {
return Channel.OP_WRITE;
}
int interestOps = getRawInterestOps();
int writeBufferSize = this.writeBufferSize.get();
if (writeBufferSize != 0) {
if (highWaterMarkCounter.get() > 0) {
int lowWaterMark = getConfig().getWriteBufferLowWaterMark();
if (writeBufferSize >= lowWaterMark) {
interestOps |= Channel.OP_WRITE;
} else {
interestOps &= ~Channel.OP_WRITE;
}
} else {
int highWaterMark = getConfig().getWriteBufferHighWaterMark();
if (writeBufferSize >= highWaterMark) {
interestOps |= Channel.OP_WRITE;
} else {
interestOps &= ~Channel.OP_WRITE;
}
}
} else {
interestOps &= ~Channel.OP_WRITE;
}
return interestOps;
}
int getRawInterestOps() {
return super.getInterestOps();
}
void setRawInterestOpsNow(int interestOps) {
super.setInterestOpsNow(interestOps);
InetSocketAddress getLocalSocketAddress() throws Exception {
return (InetSocketAddress) channel.socket().getLocalSocketAddress();
}
@Override
public ChannelFuture write(Object message, SocketAddress remoteAddress) {
if (remoteAddress == null || remoteAddress.equals(getRemoteAddress())) {
return super.write(message, null);
} else {
return getUnsupportedOperationFuture();
}
}
private final class WriteRequestQueue extends AbstractWriteRequestQueue {
private final ThreadLocalBoolean notifying = new ThreadLocalBoolean();
WriteRequestQueue() {
}
@Override
public boolean offer(MessageEvent e) {
boolean success = queue.offer(e);
assert success;
int messageSize = getMessageSize(e);
int newWriteBufferSize = writeBufferSize.addAndGet(messageSize);
int highWaterMark = getConfig().getWriteBufferHighWaterMark();
if (newWriteBufferSize >= highWaterMark) {
if (newWriteBufferSize - messageSize < highWaterMark) {
highWaterMarkCounter.incrementAndGet();
if (!notifying.get()) {
notifying.set(Boolean.TRUE);
fireChannelInterestChanged(NioSocketChannel.this);
notifying.set(Boolean.FALSE);
}
}
}
return true;
}
@Override
public MessageEvent poll() {
MessageEvent e = queue.poll();
if (e != null) {
int messageSize = getMessageSize(e);
int newWriteBufferSize = writeBufferSize.addAndGet(-messageSize);
int lowWaterMark = getConfig().getWriteBufferLowWaterMark();
if (newWriteBufferSize == 0 || newWriteBufferSize < lowWaterMark) {
if (newWriteBufferSize + messageSize >= lowWaterMark) {
highWaterMarkCounter.decrementAndGet();
if (isConnected() && !notifying.get()) {
notifying.set(Boolean.TRUE);
fireChannelInterestChanged(NioSocketChannel.this);
notifying.set(Boolean.FALSE);
}
}
}
}
return e;
}
private int getMessageSize(MessageEvent e) {
Object m = e.getMessage();
if (m instanceof ChannelBuffer) {
return ((ChannelBuffer) m).readableBytes();
}
return 0;
}
}
private final class WriteTask implements Runnable {
WriteTask() {
}
@Override
public void run() {
writeTaskInTaskQueue.set(false);
worker.writeFromTaskLoop(NioSocketChannel.this);
}
InetSocketAddress getRemoteSocketAddress() throws Exception {
return (InetSocketAddress) channel.socket().getRemoteSocketAddress();
}
}

624
transport/src/main/java/io/netty/channel/socket/nio/NioWorker.java
View File

@ -15,279 +15,38 @@
*/
package io.netty.channel.socket.nio;
import static io.netty.channel.Channels.*;
import static io.netty.channel.Channels.fireChannelBound;
import static io.netty.channel.Channels.fireChannelConnected;
import static io.netty.channel.Channels.fireExceptionCaught;
import static io.netty.channel.Channels.fireMessageReceived;
import static io.netty.channel.Channels.succeededFuture;
import io.netty.buffer.ChannelBuffer;
import io.netty.buffer.ChannelBufferFactory;
import io.netty.channel.ChannelException;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ReceiveBufferSizePredictor;
import java.io.IOException;
import java.net.SocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.AsynchronousCloseException;
import java.nio.channels.CancelledKeyException;
import java.nio.channels.ClosedChannelException;
import java.nio.channels.NotYetConnectedException;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.SocketChannel;
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.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import io.netty.buffer.ChannelBuffer;
import io.netty.buffer.ChannelBufferFactory;
import io.netty.channel.Channel;
import io.netty.channel.ChannelException;
import io.netty.channel.ChannelFuture;
import io.netty.channel.MessageEvent;
import io.netty.channel.ReceiveBufferSizePredictor;
import io.netty.channel.socket.nio.SocketSendBufferPool.SendBuffer;
import io.netty.logging.InternalLogger;
import io.netty.logging.InternalLoggerFactory;
import io.netty.util.internal.DeadLockProofWorker;
import io.netty.util.internal.QueueFactory;
class NioWorker implements Runnable {
private static final InternalLogger logger =
InternalLoggerFactory.getInstance(NioWorker.class);
private static final int CONSTRAINT_LEVEL = NioProviderMetadata.CONSTRAINT_LEVEL;
static final int CLEANUP_INTERVAL = 256; // XXX Hard-coded value, but won't need customization.
private final Executor executor;
private boolean started;
private volatile Thread thread;
volatile Selector selector;
private final AtomicBoolean wakenUp = new AtomicBoolean();
private final ReadWriteLock selectorGuard = new ReentrantReadWriteLock();
private final Object startStopLock = new Object();
private final Queue<Runnable> registerTaskQueue = QueueFactory.createQueue(Runnable.class);
private final Queue<Runnable> writeTaskQueue = QueueFactory.createQueue(Runnable.class);
private volatile int cancelledKeys; // should use AtomicInteger but we just need approximation
class NioWorker extends AbstractNioWorker {
private final SocketReceiveBufferPool recvBufferPool = new SocketReceiveBufferPool();
private final SocketSendBufferPool sendBufferPool = new SocketSendBufferPool();
NioWorker(Executor executor) {
this.executor = executor;
super(executor);
}
void register(NioSocketChannel channel, ChannelFuture future) {
boolean server = !(channel instanceof NioClientSocketChannel);
Runnable registerTask = new RegisterTask(channel, future, server);
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(executor, this);
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();
}
}
@Override
public void run() {
thread = Thread.currentThread();
boolean shutdown = false;
Selector selector = this.selector;
for (;;) {
wakenUp.set(false);
if (CONSTRAINT_LEVEL != 0) {
selectorGuard.writeLock().lock();
// This empty synchronization block prevents the selector
// from acquiring its lock.
selectorGuard.writeLock().unlock();
}
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;
processRegisterTaskQueue();
processWriteTaskQueue();
processSelectedKeys(selector.selectedKeys());
// 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
// connections are registered in a one-by-one manner instead of
// concurrent manner.
if (selector.keys().isEmpty()) {
if (shutdown ||
executor instanceof ExecutorService && ((ExecutorService) executor).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 that lead to
// excessive CPU consumption.
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// Ignore.
}
}
}
}
private void processRegisterTaskQueue() throws IOException {
for (;;) {
final Runnable task = registerTaskQueue.poll();
if (task == null) {
break;
}
task.run();
cleanUpCancelledKeys();
}
}
private void processWriteTaskQueue() throws IOException {
for (;;) {
final Runnable task = writeTaskQueue.poll();
if (task == null) {
break;
}
task.run();
cleanUpCancelledKeys();
}
}
private void processSelectedKeys(Set<SelectionKey> selectedKeys) throws IOException {
for (Iterator<SelectionKey> i = selectedKeys.iterator(); i.hasNext();) {
SelectionKey k = i.next();
i.remove();
try {
int readyOps = k.readyOps();
if ((readyOps & SelectionKey.OP_READ) != 0 || readyOps == 0) {
if (!read(k)) {
// Connection already closed - no need to handle write.
continue;
}
}
if ((readyOps & SelectionKey.OP_WRITE) != 0) {
writeFromSelectorLoop(k);
}
} catch (CancelledKeyException e) {
close(k);
}
if (cleanUpCancelledKeys()) {
break; // break the loop to avoid ConcurrentModificationException
}
}
}
private boolean cleanUpCancelledKeys() throws IOException {
if (cancelledKeys >= CLEANUP_INTERVAL) {
cancelledKeys = 0;
selector.selectNow();
return true;
}
return false;
}
private boolean read(SelectionKey k) {
protected boolean read(SelectionKey k) {
final SocketChannel ch = (SocketChannel) k.channel();
final NioSocketChannel channel = (NioSocketChannel) k.attachment();
@ -343,47 +102,9 @@ class NioWorker implements Runnable {
return true;
}
private void close(SelectionKey k) {
NioSocketChannel ch = (NioSocketChannel) k.attachment();
close(ch, succeededFuture(ch));
}
void writeFromUserCode(final NioSocketChannel channel) {
if (!channel.isConnected()) {
cleanUpWriteBuffer(channel);
return;
}
if (scheduleWriteIfNecessary(channel)) {
return;
}
// From here, we are sure Thread.currentThread() == workerThread.
if (channel.writeSuspended) {
return;
}
if (channel.inWriteNowLoop) {
return;
}
write0(channel);
}
void writeFromTaskLoop(final NioSocketChannel ch) {
if (!ch.writeSuspended) {
write0(ch);
}
}
void writeFromSelectorLoop(final SelectionKey k) {
NioSocketChannel ch = (NioSocketChannel) k.attachment();
ch.writeSuspended = false;
write0(ch);
}
private boolean scheduleWriteIfNecessary(final NioSocketChannel channel) {
@Override
protected boolean scheduleWriteIfNecessary(final AbstractNioChannel<?> channel) {
final Thread currentThread = Thread.currentThread();
final Thread workerThread = thread;
if (currentThread != workerThread) {
@ -417,310 +138,13 @@ class NioWorker implements Runnable {
return false;
}
private void write0(NioSocketChannel channel) {
boolean open = true;
boolean addOpWrite = false;
boolean removeOpWrite = false;
long writtenBytes = 0;
final SocketSendBufferPool sendBufferPool = this.sendBufferPool;
final SocketChannel ch = channel.socket;
final Queue<MessageEvent> writeBuffer = channel.writeBuffer;
final int writeSpinCount = channel.getConfig().getWriteSpinCount();
synchronized (channel.writeLock) {
channel.inWriteNowLoop = true;
for (;;) {
MessageEvent evt = channel.currentWriteEvent;
SendBuffer buf;
if (evt == null) {
if ((channel.currentWriteEvent = evt = writeBuffer.poll()) == null) {
removeOpWrite = true;
channel.writeSuspended = false;
break;
}
channel.currentWriteBuffer = buf = sendBufferPool.acquire(evt.getMessage());
} else {
buf = channel.currentWriteBuffer;
}
ChannelFuture future = evt.getFuture();
try {
long localWrittenBytes = 0;
for (int i = writeSpinCount; i > 0; i --) {
localWrittenBytes = buf.transferTo(ch);
if (localWrittenBytes != 0) {
writtenBytes += localWrittenBytes;
break;
}
if (buf.finished()) {
break;
}
}
if (buf.finished()) {
// Successful write - proceed to the next message.
buf.release();
channel.currentWriteEvent = null;
channel.currentWriteBuffer = null;
evt = null;
buf = null;
future.setSuccess();
} else {
// Not written fully - perhaps the kernel buffer is full.
addOpWrite = true;
channel.writeSuspended = true;
if (localWrittenBytes > 0) {
// Notify progress listeners if necessary.
future.setProgress(
localWrittenBytes,
buf.writtenBytes(), buf.totalBytes());
}
break;
}
} catch (AsynchronousCloseException e) {
// Doesn't need a user attention - ignore.
} catch (Throwable t) {
if (buf != null) {
buf.release();
}
channel.currentWriteEvent = null;
channel.currentWriteBuffer = null;
buf = null;
evt = null;
future.setFailure(t);
fireExceptionCaught(channel, t);
if (t instanceof IOException) {
open = false;
close(channel, succeededFuture(channel));
}
}
}
channel.inWriteNowLoop = false;
// Initially, the following block was executed after releasing
// the writeLock, but there was a race condition, and it has to be
// executed before releasing the writeLock:
//
// https://issues.jboss.org/browse/NETTY-410
//
if (open) {
if (addOpWrite) {
setOpWrite(channel);
} else if (removeOpWrite) {
clearOpWrite(channel);
}
}
}
fireWriteComplete(channel, writtenBytes);
@Override
protected Runnable createRegisterTask(AbstractNioChannel<?> channel, ChannelFuture future) {
boolean server = !(channel instanceof NioClientSocketChannel);
return new RegisterTask((NioSocketChannel) channel, future, server);
}
private void setOpWrite(NioSocketChannel channel) {
Selector selector = this.selector;
SelectionKey key = channel.socket.keyFor(selector);
if (key == null) {
return;
}
if (!key.isValid()) {
close(key);
return;
}
// interestOps can change at any time and at any thread.
// Acquire a lock to avoid possible race condition.
synchronized (channel.interestOpsLock) {
int interestOps = channel.getRawInterestOps();
if ((interestOps & SelectionKey.OP_WRITE) == 0) {
interestOps |= SelectionKey.OP_WRITE;
key.interestOps(interestOps);
channel.setRawInterestOpsNow(interestOps);
}
}
}
private void clearOpWrite(NioSocketChannel channel) {
Selector selector = this.selector;
SelectionKey key = channel.socket.keyFor(selector);
if (key == null) {
return;
}
if (!key.isValid()) {
close(key);
return;
}
// interestOps can change at any time and at any thread.
// Acquire a lock to avoid possible race condition.
synchronized (channel.interestOpsLock) {
int interestOps = channel.getRawInterestOps();
if ((interestOps & SelectionKey.OP_WRITE) != 0) {
interestOps &= ~SelectionKey.OP_WRITE;
key.interestOps(interestOps);
channel.setRawInterestOpsNow(interestOps);
}
}
}
void close(NioSocketChannel channel, ChannelFuture future) {
boolean connected = channel.isConnected();
boolean bound = channel.isBound();
try {
channel.socket.close();
cancelledKeys ++;
if (channel.setClosed()) {
future.setSuccess();
if (connected) {
fireChannelDisconnected(channel);
}
if (bound) {
fireChannelUnbound(channel);
}
cleanUpWriteBuffer(channel);
fireChannelClosed(channel);
} else {
future.setSuccess();
}
} catch (Throwable t) {
future.setFailure(t);
fireExceptionCaught(channel, t);
}
}
private void cleanUpWriteBuffer(NioSocketChannel channel) {
Exception cause = null;
boolean fireExceptionCaught = false;
// Clean up the stale messages in the write buffer.
synchronized (channel.writeLock) {
MessageEvent evt = channel.currentWriteEvent;
if (evt != null) {
// Create the exception only once to avoid the excessive overhead
// caused by fillStackTrace.
if (channel.isOpen()) {
cause = new NotYetConnectedException();
} else {
cause = new ClosedChannelException();
}
ChannelFuture future = evt.getFuture();
channel.currentWriteBuffer.release();
channel.currentWriteBuffer = null;
channel.currentWriteEvent = null;
evt = null;
future.setFailure(cause);
fireExceptionCaught = true;
}
Queue<MessageEvent> writeBuffer = channel.writeBuffer;
if (!writeBuffer.isEmpty()) {
// Create the exception only once to avoid the excessive overhead
// caused by fillStackTrace.
if (cause == null) {
if (channel.isOpen()) {
cause = new NotYetConnectedException();
} else {
cause = new ClosedChannelException();
}
}
for (;;) {
evt = writeBuffer.poll();
if (evt == null) {
break;
}
evt.getFuture().setFailure(cause);
fireExceptionCaught = true;
}
}
}
if (fireExceptionCaught) {
fireExceptionCaught(channel, cause);
}
}
void setInterestOps(
NioSocketChannel channel, ChannelFuture future, int interestOps) {
boolean changed = false;
try {
// interestOps can change at any time and at any thread.
// Acquire a lock to avoid possible race condition.
synchronized (channel.interestOpsLock) {
Selector selector = this.selector;
SelectionKey key = channel.socket.keyFor(selector);
if (key == null || selector == null) {
// Not registered to the worker yet.
// Set the rawInterestOps immediately; RegisterTask will pick it up.
channel.setRawInterestOpsNow(interestOps);
return;
}
// Override OP_WRITE flag - a user cannot change this flag.
interestOps &= ~Channel.OP_WRITE;
interestOps |= channel.getRawInterestOps() & Channel.OP_WRITE;
switch (CONSTRAINT_LEVEL) {
case 0:
if (channel.getRawInterestOps() != interestOps) {
key.interestOps(interestOps);
if (Thread.currentThread() != thread &&
wakenUp.compareAndSet(false, true)) {
selector.wakeup();
}
changed = true;
}
break;
case 1:
case 2:
if (channel.getRawInterestOps() != interestOps) {
if (Thread.currentThread() == thread) {
key.interestOps(interestOps);
changed = true;
} else {
selectorGuard.readLock().lock();
try {
if (wakenUp.compareAndSet(false, true)) {
selector.wakeup();
}
key.interestOps(interestOps);
changed = true;
} finally {
selectorGuard.readLock().unlock();
}
}
}
break;
default:
throw new Error();
}
if (changed) {
channel.setRawInterestOpsNow(interestOps);
}
}
future.setSuccess();
if (changed) {
fireChannelInterestChanged(channel);
}
} catch (CancelledKeyException e) {
// setInterestOps() was called on a closed channel.
ClosedChannelException cce = new ClosedChannelException();
future.setFailure(cce);
fireExceptionCaught(channel, cce);
} catch (Throwable t) {
future.setFailure(t);
fireExceptionCaught(channel, t);
}
}
private final class RegisterTask implements Runnable {
private final NioSocketChannel channel;
private final ChannelFuture future;
@ -738,6 +162,7 @@ class NioWorker implements Runnable {
public void run() {
SocketAddress localAddress = channel.getLocalAddress();
SocketAddress remoteAddress = channel.getRemoteAddress();
if (localAddress == null || remoteAddress == null) {
if (future != null) {
future.setFailure(new ClosedChannelException());
@ -748,11 +173,11 @@ class NioWorker implements Runnable {
try {
if (server) {
channel.socket.configureBlocking(false);
channel.channel.configureBlocking(false);
}
synchronized (channel.interestOpsLock) {
channel.socket.register(
channel.channel.register(
selector, channel.getRawInterestOps(), channel);
}
if (future != null) {
@ -776,4 +201,5 @@ class NioWorker implements Runnable {
fireChannelConnected(channel, remoteAddress);
}
}
}

2
transport/src/main/java/io/netty/channel/socket/oio/AbstractOioChannel.java
View File

@ -26,7 +26,7 @@ import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.ChannelSink;
abstract class AbstractOioChannel extends AbstractChannel{
abstract class AbstractOioChannel extends AbstractChannel {
private volatile InetSocketAddress localAddress;
volatile InetSocketAddress remoteAddress;
volatile Thread workerThread;

4
transport/src/main/java/io/netty/channel/socket/oio/OioDatagramChannel.java
View File

@ -134,12 +134,12 @@ final class OioDatagramChannel extends AbstractOioChannel
}
@Override
InetSocketAddress getLocalSocketAddress() throws Exception{
InetSocketAddress getLocalSocketAddress() throws Exception {
return (InetSocketAddress) socket.getLocalSocketAddress();
}
@Override
InetSocketAddress getRemoteSocketAddress() throws Exception{
InetSocketAddress getRemoteSocketAddress() throws Exception {
return (InetSocketAddress) socket.getRemoteSocketAddress();
}