987 lines
33 KiB
Java
987 lines
33 KiB
Java
/*
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* Copyright 2012 The Netty Project
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*
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* The Netty Project licenses this file to you under the Apache License,
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* version 2.0 (the "License"); you may not use this file except in compliance
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* with the License. You may obtain a copy of the License at:
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*
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* https://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*/
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package io.netty.util.concurrent;
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import io.netty.util.internal.SystemPropertyUtil;
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import io.netty.util.internal.ThreadExecutorMap;
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import io.netty.util.internal.logging.InternalLogger;
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import io.netty.util.internal.logging.InternalLoggerFactory;
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import java.lang.Thread.State;
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import java.util.ArrayList;
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import java.util.Collection;
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import java.util.LinkedHashSet;
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import java.util.List;
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import java.util.Queue;
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import java.util.Set;
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import java.util.concurrent.BlockingQueue;
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import java.util.concurrent.Callable;
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import java.util.concurrent.CountDownLatch;
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import java.util.concurrent.ExecutionException;
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import java.util.concurrent.Executor;
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import java.util.concurrent.LinkedBlockingQueue;
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import java.util.concurrent.RejectedExecutionException;
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import java.util.concurrent.ThreadFactory;
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import java.util.concurrent.TimeUnit;
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import java.util.concurrent.TimeoutException;
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import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
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import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
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import static java.util.Objects.requireNonNull;
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/**
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* {@link OrderedEventExecutor}'s implementation that execute all its submitted tasks in a single thread.
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*
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*/
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public class SingleThreadEventExecutor extends AbstractScheduledEventExecutor implements OrderedEventExecutor {
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protected static final int DEFAULT_MAX_PENDING_EXECUTOR_TASKS = Math.max(16,
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SystemPropertyUtil.getInt("io.netty.eventexecutor.maxPendingTasks", Integer.MAX_VALUE));
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private static final InternalLogger logger =
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InternalLoggerFactory.getInstance(SingleThreadEventExecutor.class);
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private static final int ST_NOT_STARTED = 1;
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private static final int ST_STARTED = 2;
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private static final int ST_SHUTTING_DOWN = 3;
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private static final int ST_SHUTDOWN = 4;
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private static final int ST_TERMINATED = 5;
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private static final Runnable WAKEUP_TASK = () -> {
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// Do nothing.
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};
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private static final Runnable NOOP_TASK = () -> {
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// Do nothing.
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};
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private static final AtomicIntegerFieldUpdater<SingleThreadEventExecutor> STATE_UPDATER =
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AtomicIntegerFieldUpdater.newUpdater(SingleThreadEventExecutor.class, "state");
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private static final AtomicReferenceFieldUpdater<SingleThreadEventExecutor, ThreadProperties> PROPERTIES_UPDATER =
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AtomicReferenceFieldUpdater.newUpdater(
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SingleThreadEventExecutor.class, ThreadProperties.class, "threadProperties");
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private final Queue<Runnable> taskQueue;
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private volatile Thread thread;
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@SuppressWarnings("unused")
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private volatile ThreadProperties threadProperties;
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private final Executor executor;
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private volatile boolean interrupted;
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private final CountDownLatch threadLock = new CountDownLatch(1);
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private final Set<Runnable> shutdownHooks = new LinkedHashSet<>();
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private final boolean addTaskWakesUp;
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private final RejectedExecutionHandler rejectedExecutionHandler;
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private long lastExecutionTime;
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@SuppressWarnings({ "FieldMayBeFinal", "unused" })
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private volatile int state = ST_NOT_STARTED;
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private volatile long gracefulShutdownQuietPeriod;
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private volatile long gracefulShutdownTimeout;
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private long gracefulShutdownStartTime;
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private final Promise<?> terminationFuture = new DefaultPromise<Void>(GlobalEventExecutor.INSTANCE);
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/**
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* Create a new instance
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*/
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public SingleThreadEventExecutor() {
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this(new DefaultThreadFactory(SingleThreadEventExecutor.class));
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}
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/**
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* Create a new instance
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*
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* @param threadFactory the {@link ThreadFactory} which will be used for the used {@link Thread}
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*/
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public SingleThreadEventExecutor(ThreadFactory threadFactory) {
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this(new ThreadPerTaskExecutor(threadFactory));
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}
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/**
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* Create a new instance
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*
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* @param threadFactory the {@link ThreadFactory} which will be used for the used {@link Thread}
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* @param maxPendingTasks the maximum number of pending tasks before new tasks will be rejected.
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* @param rejectedHandler the {@link RejectedExecutionHandler} to use.
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*/
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public SingleThreadEventExecutor(ThreadFactory threadFactory,
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int maxPendingTasks, RejectedExecutionHandler rejectedHandler) {
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this(new ThreadPerTaskExecutor(threadFactory), maxPendingTasks, rejectedHandler);
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}
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/**
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* Create a new instance
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*
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* @param executor the {@link Executor} which will be used for executing
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*/
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public SingleThreadEventExecutor(Executor executor) {
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this(executor, DEFAULT_MAX_PENDING_EXECUTOR_TASKS, RejectedExecutionHandlers.reject());
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}
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/**
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* Create a new instance
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*
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* @param executor the {@link Executor} which will be used for executing
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* @param maxPendingTasks the maximum number of pending tasks before new tasks will be rejected.
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* @param rejectedHandler the {@link RejectedExecutionHandler} to use.
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*/
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public SingleThreadEventExecutor(Executor executor, int maxPendingTasks, RejectedExecutionHandler rejectedHandler) {
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this.executor = ThreadExecutorMap.apply(executor, this);
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taskQueue = newTaskQueue(Math.max(16, maxPendingTasks));
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addTaskWakesUp = taskQueue instanceof BlockingQueue;
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rejectedExecutionHandler = requireNonNull(rejectedHandler, "rejectedHandler");
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}
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/**
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* Create a new {@link Queue} which will holds the tasks to execute. This default implementation will return a
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* {@link LinkedBlockingQueue} but if your sub-class of {@link SingleThreadEventExecutor} will not do any blocking
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* calls on the this {@link Queue} it may make sense to {@code @Override} this and return some more performant
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* implementation that does not support blocking operations at all.
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*
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* Be aware that the implementation of {@link #run()} depends on a {@link BlockingQueue} so you will need to
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* override {@link #run()} as well if you return a non {@link BlockingQueue} from this method.
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*
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* As this method is called from within the constructor you can only use the parameters passed into the method when
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* overriding this method.
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*/
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protected Queue<Runnable> newTaskQueue(int maxPendingTasks) {
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return new LinkedBlockingQueue<>(maxPendingTasks);
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}
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/**
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* Interrupt the current running {@link Thread}.
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*/
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protected final void interruptThread() {
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Thread currentThread = thread;
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if (currentThread == null) {
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interrupted = true;
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} else {
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currentThread.interrupt();
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}
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}
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/**
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* @see Queue#poll()
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*
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* This method must be called from the {@link EventExecutor} thread.
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*/
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protected final Runnable pollTask() {
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assert inEventLoop();
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for (;;) {
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Runnable task = taskQueue.poll();
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if (task == WAKEUP_TASK) {
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continue;
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}
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return task;
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}
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}
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/**
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* Take the next {@link Runnable} from the task queue and so will block if no task is currently present.
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* <p>
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* Be aware that this method will throw an {@link UnsupportedOperationException} if the task queue, which was
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* created via {@link #newTaskQueue(int)}, does not implement {@link BlockingQueue}.
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* </p>
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*
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* This method must be called from the {@link EventExecutor} thread.
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*
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* @return {@code null} if the executor thread has been interrupted or waken up.
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*/
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protected final Runnable takeTask() {
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assert inEventLoop();
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if (!(taskQueue instanceof BlockingQueue)) {
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throw new UnsupportedOperationException();
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}
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BlockingQueue<Runnable> taskQueue = (BlockingQueue<Runnable>) this.taskQueue;
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for (;;) {
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RunnableScheduledFuture<?> scheduledTask = peekScheduledTask();
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if (scheduledTask == null) {
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Runnable task = null;
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try {
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task = taskQueue.take();
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if (task == WAKEUP_TASK) {
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task = null;
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}
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} catch (InterruptedException e) {
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// Ignore
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}
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return task;
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} else {
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long delayNanos = scheduledTask.delayNanos();
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Runnable task = null;
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if (delayNanos > 0) {
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try {
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task = taskQueue.poll(delayNanos, TimeUnit.NANOSECONDS);
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} catch (InterruptedException e) {
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// Waken up.
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return null;
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}
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}
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if (task == null) {
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// We need to fetch the scheduled tasks now as otherwise there may be a chance that
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// scheduled tasks are never executed if there is always one task in the taskQueue.
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// This is for example true for the read task of OIO Transport
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// See https://github.com/netty/netty/issues/1614
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fetchFromScheduledTaskQueue();
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task = taskQueue.poll();
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}
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if (task != null) {
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return task;
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}
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}
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}
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}
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private boolean fetchFromScheduledTaskQueue() {
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long nanoTime = AbstractScheduledEventExecutor.nanoTime();
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RunnableScheduledFuture<?> scheduledTask = pollScheduledTask(nanoTime);
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while (scheduledTask != null) {
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if (!taskQueue.offer(scheduledTask)) {
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// No space left in the task queue add it back to the scheduledTaskQueue so we pick it up again.
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schedule(scheduledTask);
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return false;
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}
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scheduledTask = pollScheduledTask(nanoTime);
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}
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return true;
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}
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/**
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* @see Queue#isEmpty()
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*/
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protected final boolean hasTasks() {
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return !taskQueue.isEmpty();
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}
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/**
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* Return the number of tasks that are pending for processing (excluding the scheduled tasks).
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*/
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public final int pendingTasks() {
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return taskQueue.size();
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}
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/**
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* Add a task to the task queue, or throws a {@link RejectedExecutionException} if this instance was shutdown
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* before.
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*/
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private void addTask(Runnable task) {
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if (!offerTask(task)) {
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rejectedExecutionHandler.rejected(task, this);
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}
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}
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/**
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* @see Queue#offer(Object)
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*/
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protected final boolean offerTask(Runnable task) {
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requireNonNull(task, "task");
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if (isShutdown()) {
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reject();
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}
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return taskQueue.offer(task);
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}
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/**
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* @see Queue#remove(Object)
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*/
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protected final boolean removeTask(Runnable task) {
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return taskQueue.remove(task);
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}
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/**
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* Poll all tasks from the task queue and run them via {@link Runnable#run()} method.
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*
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* This method must be called from the {@link EventExecutor} thread.
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*
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* @return {@code true} if and only if at least one task was run
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*/
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private boolean runAllTasks() {
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boolean fetchedAll;
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do {
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fetchedAll = fetchFromScheduledTaskQueue();
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Runnable task = pollTask();
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if (task == null) {
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return false;
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}
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do {
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try {
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task.run();
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} catch (Throwable t) {
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logger.warn("A task raised an exception.", t);
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}
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} while ((task = pollTask()) != null);
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} while (!fetchedAll); // keep on processing until we fetched all scheduled tasks.
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updateLastExecutionTime();
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return true;
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}
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/**
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* Poll all tasks from the task queue and run them via {@link Runnable#run()} method.
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*
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* This method must be called from the {@link EventExecutor} thread.
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*
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* @return the number of processed tasks.
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*/
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protected int runAllTasks(int maxTasks) {
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assert inEventLoop();
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boolean fetchedAll;
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int processedTasks = 0;
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do {
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fetchedAll = fetchFromScheduledTaskQueue();
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for (; processedTasks < maxTasks; processedTasks++) {
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Runnable task = pollTask();
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if (task == null) {
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break;
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}
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try {
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task.run();
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} catch (Throwable t) {
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logger.warn("A task raised an exception.", t);
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}
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}
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} while (!fetchedAll && processedTasks < maxTasks); // keep on processing until we fetched all scheduled tasks.
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if (processedTasks > 0) {
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// Only call if we at least executed one task.
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updateLastExecutionTime();
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}
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return processedTasks;
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}
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/**
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* Returns the amount of time left until the scheduled task with the closest dead line is executed.
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*
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* This method must be called from the {@link EventExecutor} thread.
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*/
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protected final long delayNanos(long currentTimeNanos) {
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assert inEventLoop();
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RunnableScheduledFuture<?> scheduledTask = peekScheduledTask();
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if (scheduledTask == null) {
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return SCHEDULE_PURGE_INTERVAL;
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}
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return scheduledTask.delayNanos(currentTimeNanos);
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}
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/**
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* Returns the absolute point in time (relative to {@link #nanoTime()}) at which the the next
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* closest scheduled task should run.
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*
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* This method must be called from the {@link EventExecutor} thread.
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*/
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protected final long deadlineNanos() {
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assert inEventLoop();
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RunnableScheduledFuture<?> scheduledTask = peekScheduledTask();
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if (scheduledTask == null) {
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return nanoTime() + SCHEDULE_PURGE_INTERVAL;
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}
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return scheduledTask.deadlineNanos();
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}
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/**
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* Updates the internal timestamp that tells when a submitted task was executed most recently.
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* {@link #runAllTasks(int)} updates this timestamp automatically, and thus there's usually no need to call this
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* method. However, if you take the tasks manually using {@link #takeTask()} or {@link #pollTask()}, you have to
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* call this method at the end of task execution loop if you execute a task for accurate quiet period checks.
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*
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* This method must be called from the {@link EventExecutor} thread.
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*/
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protected final void updateLastExecutionTime() {
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assert inEventLoop();
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lastExecutionTime = nanoTime();
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}
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/**
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* Run tasks that are submitted to this {@link SingleThreadEventExecutor}.
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* The implementation depends on the fact that {@link #newTaskQueue(int)} returns a
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* {@link BlockingQueue}. If you change this by overriding {@link #newTaskQueue(int)}
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* be aware that you also need to override {@link #run()}.
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*
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* This method must be called from the {@link EventExecutor} thread.
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*/
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protected void run() {
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assert inEventLoop();
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do {
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Runnable task = takeTask();
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if (task != null) {
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task.run();
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updateLastExecutionTime();
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}
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} while (!confirmShutdown());
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}
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/**
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* Do nothing, sub-classes may override.
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*/
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protected void cleanup() {
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// NOOP
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assert inEventLoop();
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}
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protected void wakeup(boolean inEventLoop) {
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if (!inEventLoop) {
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// Use offer as we actually only need this to unblock the thread and if offer fails we do not care as there
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// is already something in the queue.
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taskQueue.offer(WAKEUP_TASK);
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}
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}
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@Override
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public final boolean inEventLoop(Thread thread) {
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return thread == this.thread;
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}
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/**
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* Add a {@link Runnable} which will be executed on shutdown of this instance
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*/
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public final void addShutdownHook(final Runnable task) {
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if (inEventLoop()) {
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shutdownHooks.add(task);
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} else {
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execute(() -> shutdownHooks.add(task));
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}
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}
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/**
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* Remove a previous added {@link Runnable} as a shutdown hook
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*/
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public final void removeShutdownHook(final Runnable task) {
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if (inEventLoop()) {
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shutdownHooks.remove(task);
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} else {
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execute(() -> shutdownHooks.remove(task));
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}
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}
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private boolean runShutdownHooks() {
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boolean ran = false;
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// Note shutdown hooks can add / remove shutdown hooks.
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while (!shutdownHooks.isEmpty()) {
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List<Runnable> copy = new ArrayList<>(shutdownHooks);
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shutdownHooks.clear();
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for (Runnable task: copy) {
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try {
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task.run();
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} catch (Throwable t) {
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logger.warn("Shutdown hook raised an exception.", t);
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} finally {
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ran = true;
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}
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}
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}
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if (ran) {
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updateLastExecutionTime();
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}
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return ran;
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}
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@Override
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public final Future<?> shutdownGracefully(long quietPeriod, long timeout, TimeUnit unit) {
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if (quietPeriod < 0) {
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throw new IllegalArgumentException("quietPeriod: " + quietPeriod + " (expected >= 0)");
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}
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if (timeout < quietPeriod) {
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throw new IllegalArgumentException(
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"timeout: " + timeout + " (expected >= quietPeriod (" + quietPeriod + "))");
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}
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requireNonNull(unit, "unit");
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if (isShuttingDown()) {
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return terminationFuture();
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}
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boolean inEventLoop = inEventLoop();
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boolean wakeup;
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int oldState;
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for (;;) {
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if (isShuttingDown()) {
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return terminationFuture();
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}
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int newState;
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wakeup = true;
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oldState = state;
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if (inEventLoop) {
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newState = ST_SHUTTING_DOWN;
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} else {
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switch (oldState) {
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case ST_NOT_STARTED:
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case ST_STARTED:
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newState = ST_SHUTTING_DOWN;
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break;
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default:
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newState = oldState;
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wakeup = false;
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}
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}
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if (STATE_UPDATER.compareAndSet(this, oldState, newState)) {
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//System.err.println(oldState + " " + newState + " " + this);
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break;
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}
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}
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gracefulShutdownQuietPeriod = unit.toNanos(quietPeriod);
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gracefulShutdownTimeout = unit.toNanos(timeout);
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|
|
if (ensureThreadStarted(oldState)) {
|
|
return terminationFuture.asFuture();
|
|
}
|
|
|
|
if (wakeup) {
|
|
taskQueue.offer(WAKEUP_TASK);
|
|
if (!addTaskWakesUp) {
|
|
wakeup(inEventLoop);
|
|
}
|
|
}
|
|
|
|
return terminationFuture();
|
|
}
|
|
|
|
@Override
|
|
public final Future<?> terminationFuture() {
|
|
return terminationFuture.asFuture();
|
|
}
|
|
|
|
@Override
|
|
@Deprecated
|
|
public final void shutdown() {
|
|
if (isShutdown()) {
|
|
return;
|
|
}
|
|
|
|
boolean inEventLoop = inEventLoop();
|
|
boolean wakeup;
|
|
int oldState;
|
|
for (;;) {
|
|
if (isShuttingDown()) {
|
|
return;
|
|
}
|
|
int newState;
|
|
wakeup = true;
|
|
oldState = state;
|
|
if (inEventLoop) {
|
|
newState = ST_SHUTDOWN;
|
|
} else {
|
|
switch (oldState) {
|
|
case ST_NOT_STARTED:
|
|
case ST_STARTED:
|
|
case ST_SHUTTING_DOWN:
|
|
newState = ST_SHUTDOWN;
|
|
break;
|
|
default:
|
|
newState = oldState;
|
|
wakeup = false;
|
|
}
|
|
}
|
|
if (STATE_UPDATER.compareAndSet(this, oldState, newState)) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (ensureThreadStarted(oldState)) {
|
|
return;
|
|
}
|
|
|
|
if (wakeup) {
|
|
taskQueue.offer(WAKEUP_TASK);
|
|
if (!addTaskWakesUp) {
|
|
wakeup(inEventLoop);
|
|
}
|
|
}
|
|
}
|
|
|
|
@Override
|
|
public final boolean isShuttingDown() {
|
|
return state >= ST_SHUTTING_DOWN;
|
|
}
|
|
|
|
@Override
|
|
public final boolean isShutdown() {
|
|
return state >= ST_SHUTDOWN;
|
|
}
|
|
|
|
@Override
|
|
public final boolean isTerminated() {
|
|
return state == ST_TERMINATED;
|
|
}
|
|
|
|
/**
|
|
* Confirm that the shutdown if the instance should be done now!
|
|
*
|
|
* This method must be called from the {@link EventExecutor} thread.
|
|
*/
|
|
protected final boolean confirmShutdown() {
|
|
return confirmShutdown0();
|
|
}
|
|
|
|
boolean confirmShutdown0() {
|
|
assert inEventLoop();
|
|
|
|
if (!isShuttingDown()) {
|
|
return false;
|
|
}
|
|
|
|
cancelScheduledTasks();
|
|
|
|
if (gracefulShutdownStartTime == 0) {
|
|
gracefulShutdownStartTime = nanoTime();
|
|
}
|
|
|
|
if (runAllTasks() || runShutdownHooks()) {
|
|
if (isShutdown()) {
|
|
// Executor shut down - no new tasks anymore.
|
|
return true;
|
|
}
|
|
|
|
// There were tasks in the queue. Wait a little bit more until no tasks are queued for the quiet period or
|
|
// terminate if the quiet period is 0.
|
|
// See https://github.com/netty/netty/issues/4241
|
|
if (gracefulShutdownQuietPeriod == 0) {
|
|
return true;
|
|
}
|
|
taskQueue.offer(WAKEUP_TASK);
|
|
return false;
|
|
}
|
|
|
|
final long nanoTime = nanoTime();
|
|
|
|
if (isShutdown() || nanoTime - gracefulShutdownStartTime > gracefulShutdownTimeout) {
|
|
return true;
|
|
}
|
|
|
|
if (nanoTime - lastExecutionTime <= gracefulShutdownQuietPeriod) {
|
|
// Check if any tasks were added to the queue every 100ms.
|
|
// TODO: Change the behavior of takeTask() so that it returns on timeout.
|
|
taskQueue.offer(WAKEUP_TASK);
|
|
try {
|
|
Thread.sleep(100);
|
|
} catch (InterruptedException e) {
|
|
// Ignore
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
// No tasks were added for last quiet period - hopefully safe to shut down.
|
|
// (Hopefully because we really cannot make a guarantee that there will be no execute() calls by a user.)
|
|
return true;
|
|
}
|
|
|
|
@Override
|
|
public final boolean awaitTermination(long timeout, TimeUnit unit) throws InterruptedException {
|
|
requireNonNull(unit, "unit");
|
|
|
|
if (inEventLoop()) {
|
|
throw new IllegalStateException("cannot await termination of the current thread");
|
|
}
|
|
|
|
threadLock.await(timeout, unit);
|
|
|
|
return isTerminated();
|
|
}
|
|
|
|
@Override
|
|
public void execute(Runnable task) {
|
|
requireNonNull(task, "task");
|
|
|
|
boolean inEventLoop = inEventLoop();
|
|
addTask(task);
|
|
if (!inEventLoop) {
|
|
startThread();
|
|
if (isShutdown()) {
|
|
boolean reject = false;
|
|
try {
|
|
if (removeTask(task)) {
|
|
reject = true;
|
|
}
|
|
} catch (UnsupportedOperationException e) {
|
|
// The task queue does not support removal so the best thing we can do is to just move on and
|
|
// hope we will be able to pick-up the task before its completely terminated.
|
|
// In worst case we will log on termination.
|
|
}
|
|
if (reject) {
|
|
reject();
|
|
}
|
|
}
|
|
}
|
|
|
|
if (!addTaskWakesUp && wakesUpForTask(task)) {
|
|
wakeup(inEventLoop);
|
|
}
|
|
}
|
|
|
|
@Override
|
|
public <T> T invokeAny(Collection<? extends Callable<T>> tasks) throws InterruptedException, ExecutionException {
|
|
throwIfInEventLoop("invokeAny");
|
|
return super.invokeAny(tasks);
|
|
}
|
|
|
|
@Override
|
|
public <T> T invokeAny(Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit)
|
|
throws InterruptedException, ExecutionException, TimeoutException {
|
|
throwIfInEventLoop("invokeAny");
|
|
return super.invokeAny(tasks, timeout, unit);
|
|
}
|
|
|
|
@Override
|
|
public <T> List<java.util.concurrent.Future<T>> invokeAll(Collection<? extends Callable<T>> tasks)
|
|
throws InterruptedException {
|
|
throwIfInEventLoop("invokeAll");
|
|
return super.invokeAll(tasks);
|
|
}
|
|
|
|
@Override
|
|
public <T> List<java.util.concurrent.Future<T>> invokeAll(
|
|
Collection<? extends Callable<T>> tasks, long timeout, TimeUnit unit) throws InterruptedException {
|
|
throwIfInEventLoop("invokeAll");
|
|
return super.invokeAll(tasks, timeout, unit);
|
|
}
|
|
|
|
private void throwIfInEventLoop(String method) {
|
|
if (inEventLoop()) {
|
|
throw new RejectedExecutionException("Calling " + method + " from within the EventLoop is not allowed");
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Returns the {@link ThreadProperties} of the {@link Thread} that powers the {@link SingleThreadEventExecutor}.
|
|
* If the {@link SingleThreadEventExecutor} is not started yet, this operation will start it and block until
|
|
* it is fully started.
|
|
*/
|
|
public final ThreadProperties threadProperties() {
|
|
ThreadProperties threadProperties = this.threadProperties;
|
|
if (threadProperties == null) {
|
|
Thread thread = this.thread;
|
|
if (thread == null) {
|
|
assert !inEventLoop();
|
|
submit(NOOP_TASK).syncUninterruptibly();
|
|
thread = this.thread;
|
|
assert thread != null;
|
|
}
|
|
|
|
threadProperties = new DefaultThreadProperties(thread);
|
|
if (!PROPERTIES_UPDATER.compareAndSet(this, null, threadProperties)) {
|
|
threadProperties = this.threadProperties;
|
|
}
|
|
}
|
|
|
|
return threadProperties;
|
|
}
|
|
|
|
/**
|
|
* Returns {@code true} if {@link #wakeup(boolean)} should be called for this {@link Runnable}, {@code false}
|
|
* otherwise.
|
|
*/
|
|
protected boolean wakesUpForTask(@SuppressWarnings("unused") Runnable task) {
|
|
return true;
|
|
}
|
|
|
|
protected static void reject() {
|
|
throw new RejectedExecutionException("event executor terminated");
|
|
}
|
|
|
|
// ScheduledExecutorService implementation
|
|
|
|
private static final long SCHEDULE_PURGE_INTERVAL = TimeUnit.SECONDS.toNanos(1);
|
|
|
|
private void startThread() {
|
|
if (state == ST_NOT_STARTED) {
|
|
if (STATE_UPDATER.compareAndSet(this, ST_NOT_STARTED, ST_STARTED)) {
|
|
boolean success = false;
|
|
try {
|
|
doStartThread();
|
|
success = true;
|
|
} finally {
|
|
if (!success) {
|
|
STATE_UPDATER.compareAndSet(this, ST_STARTED, ST_NOT_STARTED);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
private boolean ensureThreadStarted(int oldState) {
|
|
if (oldState == ST_NOT_STARTED) {
|
|
try {
|
|
doStartThread();
|
|
} catch (Throwable cause) {
|
|
STATE_UPDATER.set(this, ST_TERMINATED);
|
|
terminationFuture.tryFailure(cause);
|
|
|
|
if (cause instanceof Error) {
|
|
// Rethrow errors so they can't be ignored.
|
|
throw cause;
|
|
}
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
private void doStartThread() {
|
|
assert thread == null;
|
|
executor.execute(() -> {
|
|
thread = Thread.currentThread();
|
|
if (interrupted) {
|
|
thread.interrupt();
|
|
}
|
|
|
|
boolean success = false;
|
|
updateLastExecutionTime();
|
|
try {
|
|
run();
|
|
success = true;
|
|
} catch (Throwable t) {
|
|
logger.warn("Unexpected exception from an event executor: ", t);
|
|
} finally {
|
|
for (;;) {
|
|
int oldState = state;
|
|
if (oldState >= ST_SHUTTING_DOWN || STATE_UPDATER.compareAndSet(
|
|
this, oldState, ST_SHUTTING_DOWN)) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
// Check if confirmShutdown() was called at the end of the loop.
|
|
if (success && gracefulShutdownStartTime == 0) {
|
|
if (logger.isErrorEnabled()) {
|
|
logger.error("Buggy " + EventExecutor.class.getSimpleName() + " implementation; " +
|
|
SingleThreadEventExecutor.class.getSimpleName() + ".confirmShutdown() must " +
|
|
"be called before run() implementation terminates.");
|
|
}
|
|
}
|
|
|
|
try {
|
|
// Run all remaining tasks and shutdown hooks. At this point the event loop
|
|
// is in ST_SHUTTING_DOWN state still accepting tasks which is needed for
|
|
// graceful shutdown with quietPeriod.
|
|
for (;;) {
|
|
if (confirmShutdown()) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
// Now we want to make sure no more tasks can be added from this point. This is
|
|
// achieved by switching the state. Any new tasks beyond this point will be rejected.
|
|
for (;;) {
|
|
int oldState = state;
|
|
if (oldState >= ST_SHUTDOWN || STATE_UPDATER.compareAndSet(
|
|
this, oldState, ST_SHUTDOWN)) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
// We have the final set of tasks in the queue now, no more can be added, run all remaining.
|
|
// No need to loop here, this is the final pass.
|
|
confirmShutdown();
|
|
} finally {
|
|
try {
|
|
cleanup();
|
|
} finally {
|
|
// Lets remove all FastThreadLocals for the Thread as we are about to terminate and notify
|
|
// the future. The user may block on the future and once it unblocks the JVM may terminate
|
|
// and start unloading classes.
|
|
// See https://github.com/netty/netty/issues/6596.
|
|
FastThreadLocal.removeAll();
|
|
|
|
STATE_UPDATER.set(this, ST_TERMINATED);
|
|
threadLock.countDown();
|
|
int numUserTasks = drainTasks();
|
|
if (numUserTasks > 0 && logger.isWarnEnabled()) {
|
|
logger.warn("An event executor terminated with " +
|
|
"non-empty task queue (" + numUserTasks + ')');
|
|
}
|
|
terminationFuture.setSuccess(null);
|
|
}
|
|
}
|
|
}
|
|
});
|
|
}
|
|
|
|
final int drainTasks() {
|
|
int numTasks = 0;
|
|
for (;;) {
|
|
Runnable runnable = taskQueue.poll();
|
|
if (runnable == null) {
|
|
break;
|
|
}
|
|
// WAKEUP_TASK should be just discarded as these are added internally.
|
|
// The important bit is that we not have any user tasks left.
|
|
if (WAKEUP_TASK != runnable) {
|
|
numTasks++;
|
|
}
|
|
}
|
|
return numTasks;
|
|
}
|
|
|
|
private static final class DefaultThreadProperties implements ThreadProperties {
|
|
private final Thread t;
|
|
|
|
DefaultThreadProperties(Thread t) {
|
|
this.t = t;
|
|
}
|
|
|
|
@Override
|
|
public State state() {
|
|
return t.getState();
|
|
}
|
|
|
|
@Override
|
|
public int priority() {
|
|
return t.getPriority();
|
|
}
|
|
|
|
@Override
|
|
public boolean isInterrupted() {
|
|
return t.isInterrupted();
|
|
}
|
|
|
|
@Override
|
|
public boolean isDaemon() {
|
|
return t.isDaemon();
|
|
}
|
|
|
|
@Override
|
|
public String name() {
|
|
return t.getName();
|
|
}
|
|
|
|
@Override
|
|
public long id() {
|
|
return t.getId();
|
|
}
|
|
|
|
@Override
|
|
public StackTraceElement[] stackTrace() {
|
|
return t.getStackTrace();
|
|
}
|
|
|
|
@Override
|
|
public boolean isAlive() {
|
|
return t.isAlive();
|
|
}
|
|
}
|
|
}
|