/*
* 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.ChannelPromise;
import io.netty.util.concurrent.EventExecutor;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
/**
* Triggers an {@link IdleStateEvent} when a {@link Channel} has not performed
* read, write, or both operation for a while.
*
* <h3>Supported idle states</h3>
* <table border="1">
* <tr>
* <th>Property</th><th>Meaning</th>
* </tr>
* <tr>
* <td>{@code readerIdleTime}</td>
* <td>an {@link IdleStateEvent} whose state is {@link IdleState#READER_IDLE}
* will be triggered when no read was performed for the specified period of
* time. Specify {@code 0} to disable.</td>
* </tr>
* <tr>
* <td>{@code writerIdleTime}</td>
* <td>an {@link IdleStateEvent} whose state is {@link IdleState#WRITER_IDLE}
* will be triggered when no write was performed for the specified period of
* time. Specify {@code 0} to disable.</td>
* </tr>
* <tr>
* <td>{@code allIdleTime}</td>
* <td>an {@link IdleStateEvent} whose state is {@link IdleState#ALL_IDLE}
* will be triggered when neither read nor write was performed for the
* specified period of time. Specify {@code 0} to disable.</td>
* </tr>
* </table>
*
* <pre>
* // An example that sends a ping message when there is no outbound traffic
* // for 30 seconds. The connection is closed when there is no inbound traffic
* // for 60 seconds.
*
* public class MyChannelInitializer extends {@link ChannelInitializer}<{@link Channel}> {
* {@code @Override}
* public void initChannel({@link Channel} channel) {
* channel.pipeline().addLast("idleStateHandler", new {@link IdleStateHandler}(60, 30, 0));
* channel.pipeline().addLast("myHandler", new MyHandler());
* }
* }
*
* // Handler should handle the {@link IdleStateEvent} triggered by {@link IdleStateHandler}.
* public class MyHandler extends {@link ChannelDuplexHandler} {
* {@code @Override}
* public void userEventTriggered({@link ChannelHandlerContext} ctx, {@link Object} evt) throws {@link Exception} {
* if (evt instanceof {@link IdleStateEvent}) {
* {@link IdleStateEvent} e = ({@link IdleStateEvent}) evt;
* if (e.state() == {@link IdleState}.READER_IDLE) {
* ctx.close();
* } else if (e.state() == {@link IdleState}.WRITER_IDLE) {
* ctx.writeAndFlush(new PingMessage());
* }
* }
* }
* }
*
* {@link ServerBootstrap} bootstrap = ...;
* ...
* bootstrap.childHandler(new MyChannelInitializer());
* ...
* </pre>
*
* @see ReadTimeoutHandler
* @see WriteTimeoutHandler
*/
public class IdleStateHandler extends ChannelDuplexHandler {
private static final long MIN_TIMEOUT_NANOS = TimeUnit.MILLISECONDS.toNanos(1);
private final long readerIdleTimeNanos;
private final long writerIdleTimeNanos;
private final long allIdleTimeNanos;
volatile ScheduledFuture<?> readerIdleTimeout;
volatile long lastReadTime;
private boolean firstReaderIdleEvent = true;
volatile ScheduledFuture<?> writerIdleTimeout;
volatile long lastWriteTime;
private boolean firstWriterIdleEvent = true;
volatile ScheduledFuture<?> allIdleTimeout;
private boolean firstAllIdleEvent = true;
private volatile int state; // 0 - none, 1 - initialized, 2 - destroyed
/**
* Creates a new instance firing {@link IdleStateEvent}s.
*
* @param readerIdleTimeSeconds
* an {@link IdleStateEvent} whose state is {@link IdleState#READER_IDLE}
* will be triggered when no read was performed for the specified
* period of time. Specify {@code 0} to disable.
* @param writerIdleTimeSeconds
* an {@link IdleStateEvent} whose state is {@link IdleState#WRITER_IDLE}
* will be triggered when no write was performed for the specified
* period of time. Specify {@code 0} to disable.
* @param allIdleTimeSeconds
* an {@link IdleStateEvent} whose state is {@link IdleState#ALL_IDLE}
* will be triggered when neither read nor write was performed for
* the specified period of time. Specify {@code 0} to disable.
*/
public IdleStateHandler(
int readerIdleTimeSeconds,
int writerIdleTimeSeconds,
int allIdleTimeSeconds) {
this(readerIdleTimeSeconds, writerIdleTimeSeconds, allIdleTimeSeconds,
TimeUnit.SECONDS);
}
/**
* Creates a new instance firing {@link IdleStateEvent}s.
*
* @param readerIdleTime
* an {@link IdleStateEvent} whose state is {@link IdleState#READER_IDLE}
* will be triggered when no read was performed for the specified
* period of time. Specify {@code 0} to disable.
* @param writerIdleTime
* an {@link IdleStateEvent} whose state is {@link IdleState#WRITER_IDLE}
* will be triggered when no write was performed for the specified
* period of time. Specify {@code 0} to disable.
* @param allIdleTime
* an {@link IdleStateEvent} whose state is {@link IdleState#ALL_IDLE}
* will be triggered when neither read nor write was performed for
* the specified period of time. Specify {@code 0} to disable.
* @param unit
* the {@link TimeUnit} of {@code readerIdleTime},
* {@code writeIdleTime}, and {@code allIdleTime}
*/
public IdleStateHandler(
long readerIdleTime, long writerIdleTime, long allIdleTime,
TimeUnit unit) {
if (unit == null) {
throw new NullPointerException("unit");
}
if (readerIdleTime <= 0) {
readerIdleTimeNanos = 0;
} else {
readerIdleTimeNanos = Math.max(unit.toNanos(readerIdleTime), MIN_TIMEOUT_NANOS);
}
if (writerIdleTime <= 0) {
writerIdleTimeNanos = 0;
} else {
writerIdleTimeNanos = Math.max(unit.toNanos(writerIdleTime), MIN_TIMEOUT_NANOS);
}
if (allIdleTime <= 0) {
allIdleTimeNanos = 0;
} else {
allIdleTimeNanos = Math.max(unit.toNanos(allIdleTime), MIN_TIMEOUT_NANOS);
}
}
/**
* Return the readerIdleTime that was given when instance this class in milliseconds.
*
*/
public long getReaderIdleTimeInMillis() {
return TimeUnit.NANOSECONDS.toMillis(readerIdleTimeNanos);
}
/**
* Return the writerIdleTime that was given when instance this class in milliseconds.
*
*/
public long getWriterIdleTimeInMillis() {
return TimeUnit.NANOSECONDS.toMillis(writerIdleTimeNanos);
}
/**
* Return the allIdleTime that was given when instance this class in milliseconds.
*
*/
public long getAllIdleTimeInMillis() {
return TimeUnit.NANOSECONDS.toMillis(allIdleTimeNanos);
}
@Override
public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
if (ctx.channel().isActive() && ctx.channel().isRegistered()) {
// channelActvie() event has been fired already, which means this.channelActive() will
// not be invoked. We have to initialize here instead.
initialize(ctx);
} else {
// channelActive() event has not been fired yet. this.channelActive() will be invoked
// and initialization will occur there.
}
}
@Override
public void handlerRemoved(ChannelHandlerContext ctx) throws Exception {
destroy();
}
@Override
public void channelRegistered(ChannelHandlerContext ctx) throws Exception {
// Initialize early if channel is active already.
if (ctx.channel().isActive()) {
initialize(ctx);
}
super.channelRegistered(ctx);
}
@Override
public void channelActive(ChannelHandlerContext ctx) throws Exception {
// This method will be invoked only if this handler was added
// before channelActive() event is fired. If a user adds this handler
// after the channelActive() event, initialize() will be called by beforeAdd().
initialize(ctx);
super.channelActive(ctx);
}
@Override
public void channelInactive(ChannelHandlerContext ctx) throws Exception {
destroy();
super.channelInactive(ctx);
}
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
lastReadTime = System.nanoTime();
firstReaderIdleEvent = firstAllIdleEvent = true;
ctx.fireChannelRead(msg);
}
@Override
public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception {
promise.addListener(new ChannelFutureListener() {
@Override
public void operationComplete(ChannelFuture future) throws Exception {
lastWriteTime = System.nanoTime();
firstWriterIdleEvent = firstAllIdleEvent = true;
}
});
ctx.write(msg, promise);
}
private void initialize(ChannelHandlerContext ctx) {
// Avoid the case where destroy() is called before scheduling timeouts.
// See: https://github.com/netty/netty/issues/143
switch (state) {
case 1:
case 2:
return;
}
state = 1;
EventExecutor loop = ctx.executor();
lastReadTime = lastWriteTime = System.nanoTime();
if (readerIdleTimeNanos > 0) {
readerIdleTimeout = loop.schedule(
new ReaderIdleTimeoutTask(ctx),
readerIdleTimeNanos, TimeUnit.NANOSECONDS);
}
if (writerIdleTimeNanos > 0) {
writerIdleTimeout = loop.schedule(
new WriterIdleTimeoutTask(ctx),
writerIdleTimeNanos, TimeUnit.NANOSECONDS);
}
if (allIdleTimeNanos > 0) {
allIdleTimeout = loop.schedule(
new AllIdleTimeoutTask(ctx),
allIdleTimeNanos, TimeUnit.NANOSECONDS);
}
}
private void destroy() {
state = 2;
if (readerIdleTimeout != null) {
readerIdleTimeout.cancel(false);
readerIdleTimeout = null;
}
if (writerIdleTimeout != null) {
writerIdleTimeout.cancel(false);
writerIdleTimeout = null;
}
if (allIdleTimeout != null) {
allIdleTimeout.cancel(false);
allIdleTimeout = null;
}
}
/**
* Is called when an {@link IdleStateEvent} should be fired. This implementation calls
* {@link ChannelHandlerContext#fireUserEventTriggered(Object)}.
*/
protected void channelIdle(ChannelHandlerContext ctx, IdleStateEvent evt) throws Exception {
ctx.fireUserEventTriggered(evt);
}
private final class ReaderIdleTimeoutTask implements Runnable {
private final ChannelHandlerContext ctx;
ReaderIdleTimeoutTask(ChannelHandlerContext ctx) {
this.ctx = ctx;
}
@Override
public void run() {
if (!ctx.channel().isOpen()) {
return;
}
long currentTime = System.nanoTime();
long lastReadTime = IdleStateHandler.this.lastReadTime;
long nextDelay = readerIdleTimeNanos - (currentTime - lastReadTime);
if (nextDelay <= 0) {
// Reader is idle - set a new timeout and notify the callback.
readerIdleTimeout =
ctx.executor().schedule(this, readerIdleTimeNanos, TimeUnit.NANOSECONDS);
try {
IdleStateEvent event;
if (firstReaderIdleEvent) {
firstReaderIdleEvent = false;
event = IdleStateEvent.FIRST_READER_IDLE_STATE_EVENT;
} else {
event = IdleStateEvent.READER_IDLE_STATE_EVENT;
}
channelIdle(ctx, event);
} catch (Throwable t) {
ctx.fireExceptionCaught(t);
}
} else {
// Read occurred before the timeout - set a new timeout with shorter delay.
readerIdleTimeout = ctx.executor().schedule(this, nextDelay, TimeUnit.NANOSECONDS);
}
}
}
private final class WriterIdleTimeoutTask implements Runnable {
private final ChannelHandlerContext ctx;
WriterIdleTimeoutTask(ChannelHandlerContext ctx) {
this.ctx = ctx;
}
@Override
public void run() {
if (!ctx.channel().isOpen()) {
return;
}
long currentTime = System.nanoTime();
long lastWriteTime = IdleStateHandler.this.lastWriteTime;
long nextDelay = writerIdleTimeNanos - (currentTime - lastWriteTime);
if (nextDelay <= 0) {
// Writer is idle - set a new timeout and notify the callback.
writerIdleTimeout = ctx.executor().schedule(
this, writerIdleTimeNanos, TimeUnit.NANOSECONDS);
try {
IdleStateEvent event;
if (firstWriterIdleEvent) {
firstWriterIdleEvent = false;
event = IdleStateEvent.FIRST_WRITER_IDLE_STATE_EVENT;
} else {
event = IdleStateEvent.WRITER_IDLE_STATE_EVENT;
}
channelIdle(ctx, event);
} catch (Throwable t) {
ctx.fireExceptionCaught(t);
}
} else {
// Write occurred before the timeout - set a new timeout with shorter delay.
writerIdleTimeout = ctx.executor().schedule(this, nextDelay, TimeUnit.NANOSECONDS);
}
}
}
private final class AllIdleTimeoutTask implements Runnable {
private final ChannelHandlerContext ctx;
AllIdleTimeoutTask(ChannelHandlerContext ctx) {
this.ctx = ctx;
}
@Override
public void run() {
if (!ctx.channel().isOpen()) {
return;
}
long currentTime = System.nanoTime();
long lastIoTime = Math.max(lastReadTime, lastWriteTime);
long nextDelay = allIdleTimeNanos - (currentTime - lastIoTime);
if (nextDelay <= 0) {
// Both reader and writer are idle - set a new timeout and
// notify the callback.
allIdleTimeout = ctx.executor().schedule(
this, allIdleTimeNanos, TimeUnit.NANOSECONDS);
try {
IdleStateEvent event;
if (firstAllIdleEvent) {
firstAllIdleEvent = false;
event = IdleStateEvent.FIRST_ALL_IDLE_STATE_EVENT;
} else {
event = IdleStateEvent.ALL_IDLE_STATE_EVENT;
}
channelIdle(ctx, event);
} catch (Throwable t) {
ctx.fireExceptionCaught(t);
}
} else {
// Either read or write occurred before the timeout - set a new
// timeout with shorter delay.
allIdleTimeout = ctx.executor().schedule(this, nextDelay, TimeUnit.NANOSECONDS);
}
}
}
}