/*
* Copyright 2002-2014 the original author or authors.
*
* Licensed 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 org.springframework.scheduling.concurrent;
import java.util.concurrent.ForkJoinPool;
import java.util.concurrent.TimeUnit;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.FactoryBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.lang.UsesJava7;
/**
* A Spring {@link FactoryBean} that builds and exposes a preconfigured {@link ForkJoinPool}.
* May be used on Java 7 and 8 as well as on Java 6 with {@code jsr166.jar} on the classpath
* (ideally on the VM bootstrap classpath).
*
* <p>For details on the ForkJoinPool API and its use with RecursiveActions, see the
* <a href="http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ForkJoinPool.html">JDK 7 javadoc</a>.
*
* <p>{@code jsr166.jar}, containing {@code java.util.concurrent} updates for Java 6, can be obtained
* from the <a href="http://gee.cs.oswego.edu/dl/concurrency-interest/">concurrency interest website</a>.
*
* @author Juergen Hoeller
* @since 3.1
*/
@UsesJava7
public class ForkJoinPoolFactoryBean implements FactoryBean<ForkJoinPool>, InitializingBean, DisposableBean {
private boolean commonPool = false;
private int parallelism = Runtime.getRuntime().availableProcessors();
private ForkJoinPool.ForkJoinWorkerThreadFactory threadFactory = ForkJoinPool.defaultForkJoinWorkerThreadFactory;
private Thread.UncaughtExceptionHandler uncaughtExceptionHandler;
private boolean asyncMode = false;
private int awaitTerminationSeconds = 0;
private ForkJoinPool forkJoinPool;
/**
* Set whether to expose JDK 8's 'common' {@link ForkJoinPool}.
* <p>Default is "false", creating a local {@link ForkJoinPool} instance based on the
* {@link #setParallelism "parallelism"}, {@link #setThreadFactory "threadFactory"},
* {@link #setUncaughtExceptionHandler "uncaughtExceptionHandler"} and
* {@link #setAsyncMode "asyncMode"} properties on this FactoryBean.
* <p><b>NOTE:</b> Setting this flag to "true" effectively ignores all other
* properties on this FactoryBean, reusing the shared common JDK {@link ForkJoinPool}
* instead. This is a fine choice on JDK 8 but does remove the application's ability
* to customize ForkJoinPool behavior, in particular the use of custom threads.
* @since 3.2
* @see java.util.concurrent.ForkJoinPool#commonPool()
*/
public void setCommonPool(boolean commonPool) {
this.commonPool = commonPool;
}
/**
* Specify the parallelism level. Default is {@link Runtime#availableProcessors()}.
*/
public void setParallelism(int parallelism) {
this.parallelism = parallelism;
}
/**
* Set the factory for creating new ForkJoinWorkerThreads.
* Default is {@link ForkJoinPool#defaultForkJoinWorkerThreadFactory}.
*/
public void setThreadFactory(ForkJoinPool.ForkJoinWorkerThreadFactory threadFactory) {
this.threadFactory = threadFactory;
}
/**
* Set the handler for internal worker threads that terminate due to unrecoverable errors
* encountered while executing tasks. Default is none.
*/
public void setUncaughtExceptionHandler(Thread.UncaughtExceptionHandler uncaughtExceptionHandler) {
this.uncaughtExceptionHandler = uncaughtExceptionHandler;
}
/**
* Specify whether to establish a local first-in-first-out scheduling mode for forked tasks
* that are never joined. This mode (asyncMode = {@code true}) may be more appropriate
* than the default locally stack-based mode in applications in which worker threads only
* process event-style asynchronous tasks. Default is {@code false}.
*/
public void setAsyncMode(boolean asyncMode) {
this.asyncMode = asyncMode;
}
/**
* Set the maximum number of seconds that this ForkJoinPool is supposed to block
* on shutdown in order to wait for remaining tasks to complete their execution
* before the rest of the container continues to shut down. This is particularly
* useful if your remaining tasks are likely to need access to other resources
* that are also managed by the container.
* <p>By default, this ForkJoinPool won't wait for the termination of tasks at all.
* It will continue to fully execute all ongoing tasks as well as all remaining
* tasks in the queue, in parallel to the rest of the container shutting down.
* In contrast, if you specify an await-termination period using this property,
* this executor will wait for the given time (max) for the termination of tasks.
* <p>Note that this feature works for the {@link #setCommonPool "commonPool"}
* mode as well. The underlying ForkJoinPool won't actually terminate in that
* case but will wait for all tasks to terminate.
* @see java.util.concurrent.ForkJoinPool#shutdown()
* @see java.util.concurrent.ForkJoinPool#awaitTermination
*/
public void setAwaitTerminationSeconds(int awaitTerminationSeconds) {
this.awaitTerminationSeconds = awaitTerminationSeconds;
}
@Override
public void afterPropertiesSet() {
this.forkJoinPool = (this.commonPool ? ForkJoinPool.commonPool() :
new ForkJoinPool(this.parallelism, this.threadFactory, this.uncaughtExceptionHandler, this.asyncMode));
}
@Override
public ForkJoinPool getObject() {
return this.forkJoinPool;
}
@Override
public Class<?> getObjectType() {
return ForkJoinPool.class;
}
@Override
public boolean isSingleton() {
return true;
}
@Override
public void destroy() {
// Ignored for the common pool.
this.forkJoinPool.shutdown();
// Wait for all tasks to terminate - works for the common pool as well.
if (this.awaitTerminationSeconds > 0) {
try {
this.forkJoinPool.awaitTermination(this.awaitTerminationSeconds, TimeUnit.SECONDS);
}
catch (InterruptedException ex) {
Thread.currentThread().interrupt();
}
}
}
}