/*
* JBoss, Home of Professional Open Source
*
* Copyright 2008, Red Hat Middleware LLC, and individual contributors
* by the @author tags. See the COPYRIGHT.txt in the distribution for a
* full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.netty.channel.socket.nio;
import static org.jboss.netty.channel.Channels.*;
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 org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.channel.AbstractChannel;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelException;
import org.jboss.netty.channel.ChannelFactory;
import org.jboss.netty.channel.ChannelFuture;
import org.jboss.netty.channel.ChannelPipeline;
import org.jboss.netty.channel.ChannelSink;
import org.jboss.netty.channel.MessageEvent;
import org.jboss.netty.channel.socket.DatagramChannelConfig;
import org.jboss.netty.util.internal.LinkedTransferQueue;
import org.jboss.netty.util.internal.ThreadLocalBoolean;
/**
* Provides an NIO based {@link org.jboss.netty.channel.socket.DatagramChannel}.
*
* @author The Netty Project (netty-dev@lists.jboss.org)
* @author Trustin Lee (tlee@redhat.com)
* @author Daniel Bevenius (dbevenius@jboss.com)
*
* @version $Rev: 1552 $, $Date: 2009-07-14 14:28:07 +0900 (Tue, 14 Jul 2009) $
*/
class NioDatagramChannel extends AbstractChannel
implements org.jboss.netty.channel.socket.DatagramChannel {
/**
* The {@link DatagramChannelConfig}.
*/
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 WriteBufferQueue}.
*/
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 WriteBufferQueue();
/**
* Keeps track of the number of bytes that the {@link WriteBufferQueue} currently
* contains.
*/
final AtomicInteger writeBufferSize = new AtomicInteger();
/**
* Keeps track of the highWaterMark.
*/
final AtomicInteger highWaterMarkCounter = new AtomicInteger();
/**
* The current write {@link MessageEvent}
*/
MessageEvent currentWriteEvent;
/**
* Boolean that indicates that write operation is in progress.
*/
volatile boolean inWriteNowLoop;
private volatile InetSocketAddress localAddress;
volatile InetSocketAddress remoteAddress;
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());
fireChannelOpen(this);
}
private DatagramChannel openNonBlockingChannel() {
try {
final DatagramChannel channel = DatagramChannel.open();
channel.configureBlocking(false);
return channel;
} catch (final IOException e) {
throw new ChannelException("Failed to open a DatagramChannel.", e);
}
}
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;
}
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;
}
public boolean isBound() {
return isOpen() && datagramChannel.socket().isBound();
}
public boolean isConnected() {
return datagramChannel.socket().isConnected();
}
@Override
protected boolean setClosed() {
return super.setClosed();
}
public NioDatagramChannelConfig getConfig() {
return config;
}
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);
}
}
/**
* WriteBuffer is an extension of {@link LinkedTransferQueue} that adds
* support for highWaterMark checking of the write buffer size.
*/
private final class WriteBufferQueue extends
LinkedTransferQueue<MessageEvent> {
private final ThreadLocalBoolean notifying = new ThreadLocalBoolean();
WriteBufferQueue() {
super();
}
/**
* This method first delegates to {@link LinkedTransferQueue#offer(Object)} and
* adds support for keeping track of the size of the this write buffer.
*/
@Override
public boolean offer(MessageEvent e) {
boolean success = super.offer(e);
assert success;
int messageSize = ((ChannelBuffer) e.getMessage()).readableBytes();
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 LinkedTransferQueue#poll()} and
* adds support for keeping track of the size of the this writebuffers queue.
*/
@Override
public MessageEvent poll() {
MessageEvent e = super.poll();
if (e != null) {
int messageSize = ((ChannelBuffer) e.getMessage()).readableBytes();
int newWriteBufferSize = writeBufferSize.addAndGet(-messageSize);
int lowWaterMark = getConfig().getWriteBufferLowWaterMark();
if (newWriteBufferSize == 0 || newWriteBufferSize < lowWaterMark) {
if (newWriteBufferSize + messageSize >= lowWaterMark) {
highWaterMarkCounter.decrementAndGet();
if (!notifying.get()) {
notifying.set(Boolean.TRUE);
fireChannelInterestChanged(NioDatagramChannel.this);
notifying.set(Boolean.FALSE);
}
}
}
}
return e;
}
}
/**
* WriteTask is a simple runnable performs writes by delegating the {@link NioDatagramWorker}.
*
*/
private final class WriteTask implements Runnable {
WriteTask() {
super();
}
public void run() {
writeTaskInTaskQueue.set(false);
NioDatagramWorker.write(NioDatagramChannel.this, false);
}
}
public void joinGroup(InetAddress multicastAddress) {
throw new UnsupportedOperationException();
}
public void joinGroup(InetSocketAddress multicastAddress,
NetworkInterface networkInterface) {
throw new UnsupportedOperationException();
}
public void leaveGroup(InetAddress multicastAddress) {
throw new UnsupportedOperationException();
}
public void leaveGroup(InetSocketAddress multicastAddress,
NetworkInterface networkInterface) {
throw new UnsupportedOperationException();
}
}