/*
* Copyright 2012 The Netty Project
*
* The Netty Project licenses this file to you under the Apache License,
* version 2.0 (the "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*/
package io.netty.handler.timeout;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.Channel;
import io.netty.channel.ChannelDuplexHandler;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOutboundHandlerAdapter;
import io.netty.channel.ChannelPromise;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
/**
* Raises a {@link WriteTimeoutException} when no data was written within a
* certain period of time.
*
* <pre>
* // The connection is closed when there is no outbound traffic
* // for 30 seconds.
*
* public class MyChannelInitializer extends {@link ChannelInitializer}<{@link Channel}> {
* public void initChannel({@link Channel} channel) {
* channel.pipeline().addLast("writeTimeoutHandler", new {@link WriteTimeoutHandler}(30);
* channel.pipeline().addLast("myHandler", new MyHandler());
* }
* }
*
* // Handler should handle the {@link WriteTimeoutException}.
* public class MyHandler extends {@link ChannelDuplexHandler} {
* {@code @Override}
* public void exceptionCaught({@link ChannelHandlerContext} ctx, {@link Throwable} cause)
* throws {@link Exception} {
* if (cause instanceof {@link WriteTimeoutException}) {
* // do something
* } else {
* super.exceptionCaught(ctx, cause);
* }
* }
* }
*
* {@link ServerBootstrap} bootstrap = ...;
* ...
* bootstrap.childHandler(new MyChannelInitializer());
* ...
* </pre>
* @see ReadTimeoutHandler
* @see IdleStateHandler
*/
public class WriteTimeoutHandler extends ChannelOutboundHandlerAdapter {
private static final long MIN_TIMEOUT_NANOS = TimeUnit.MILLISECONDS.toNanos(1);
private final long timeoutNanos;
private boolean closed;
/**
* Creates a new instance.
*
* @param timeoutSeconds
* write timeout in seconds
*/
public WriteTimeoutHandler(int timeoutSeconds) {
this(timeoutSeconds, TimeUnit.SECONDS);
}
/**
* Creates a new instance.
*
* @param timeout
* write timeout
* @param unit
* the {@link TimeUnit} of {@code timeout}
*/
public WriteTimeoutHandler(long timeout, TimeUnit unit) {
if (unit == null) {
throw new NullPointerException("unit");
}
if (timeout <= 0) {
timeoutNanos = 0;
} else {
timeoutNanos = Math.max(unit.toNanos(timeout), MIN_TIMEOUT_NANOS);
}
}
@Override
public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception {
scheduleTimeout(ctx, promise);
ctx.write(msg, promise);
}
private void scheduleTimeout(final ChannelHandlerContext ctx, final ChannelPromise future) {
if (timeoutNanos > 0) {
// Schedule a timeout.
final ScheduledFuture<?> sf = ctx.executor().schedule(new Runnable() {
@Override
public void run() {
// Was not written yet so issue a write timeout
// The future itself will be failed with a ClosedChannelException once the close() was issued
// See https://github.com/netty/netty/issues/2159
if (!future.isDone()) {
try {
writeTimedOut(ctx);
} catch (Throwable t) {
ctx.fireExceptionCaught(t);
}
}
}
}, timeoutNanos, TimeUnit.NANOSECONDS);
// Cancel the scheduled timeout if the flush future is complete.
future.addListener(new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture future) throws Exception {
sf.cancel(false);
}
});
}
}
/**
* Is called when a write timeout was detected
*/
protected void writeTimedOut(ChannelHandlerContext ctx) throws Exception {
if (!closed) {
ctx.fireExceptionCaught(WriteTimeoutException.INSTANCE);
ctx.close();
closed = true;
}
}
}