/*
* Copyright 2002-2013 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.ExecutorService;
import java.util.concurrent.RejectedExecutionHandler;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.BeanNameAware;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.InitializingBean;
/**
* Base class for classes that are setting up a
* {@code java.util.concurrent.ExecutorService}
* (typically a {@link java.util.concurrent.ThreadPoolExecutor}).
* Defines common configuration settings and common lifecycle handling.
*
* @author Juergen Hoeller
* @since 3.0
* @see java.util.concurrent.ExecutorService
* @see java.util.concurrent.Executors
* @see java.util.concurrent.ThreadPoolExecutor
*/
@SuppressWarnings("serial")
public abstract class ExecutorConfigurationSupport extends CustomizableThreadFactory
implements BeanNameAware, InitializingBean, DisposableBean {
protected final Log logger = LogFactory.getLog(getClass());
private ThreadFactory threadFactory = this;
private boolean threadNamePrefixSet = false;
private RejectedExecutionHandler rejectedExecutionHandler = new ThreadPoolExecutor.AbortPolicy();
private boolean waitForTasksToCompleteOnShutdown = false;
private int awaitTerminationSeconds = 0;
private String beanName;
private ExecutorService executor;
/**
* Set the ThreadFactory to use for the ExecutorService's thread pool.
* Default is the underlying ExecutorService's default thread factory.
* <p>In a Java EE 7 or other managed environment with JSR-236 support,
* consider specifying a JNDI-located ManagedThreadFactory: by default,
* to be found at "java:comp/DefaultManagedThreadFactory".
* Use the "jee:jndi-lookup" namespace element in XML or the programmatic
* {@link org.springframework.jndi.JndiLocatorDelegate} for convenient lookup.
* Alternatively, consider using Spring's {@link DefaultManagedAwareThreadFactory}
* with its fallback to local threads in case of no managed thread factory found.
* @see java.util.concurrent.Executors#defaultThreadFactory()
* @see javax.enterprise.concurrent.ManagedThreadFactory
* @see DefaultManagedAwareThreadFactory
*/
public void setThreadFactory(ThreadFactory threadFactory) {
this.threadFactory = (threadFactory != null ? threadFactory : this);
}
@Override
public void setThreadNamePrefix(String threadNamePrefix) {
super.setThreadNamePrefix(threadNamePrefix);
this.threadNamePrefixSet = true;
}
/**
* Set the RejectedExecutionHandler to use for the ExecutorService.
* Default is the ExecutorService's default abort policy.
* @see java.util.concurrent.ThreadPoolExecutor.AbortPolicy
*/
public void setRejectedExecutionHandler(RejectedExecutionHandler rejectedExecutionHandler) {
this.rejectedExecutionHandler =
(rejectedExecutionHandler != null ? rejectedExecutionHandler : new ThreadPoolExecutor.AbortPolicy());
}
/**
* Set whether to wait for scheduled tasks to complete on shutdown,
* not interrupting running tasks and executing all tasks in the queue.
* <p>Default is "false", shutting down immediately through interrupting
* ongoing tasks and clearing the queue. Switch this flag to "true" if you
* prefer fully completed tasks at the expense of a longer shutdown phase.
* <p>Note that Spring's container shutdown continues while ongoing tasks
* are being completed. If you want this executor to block and wait for the
* termination of tasks before the rest of the container continues to shut
* down - e.g. in order to keep up other resources that your tasks may need -,
* set the {@link #setAwaitTerminationSeconds "awaitTerminationSeconds"}
* property instead of or in addition to this property.
* @see java.util.concurrent.ExecutorService#shutdown()
* @see java.util.concurrent.ExecutorService#shutdownNow()
*/
public void setWaitForTasksToCompleteOnShutdown(boolean waitForJobsToCompleteOnShutdown) {
this.waitForTasksToCompleteOnShutdown = waitForJobsToCompleteOnShutdown;
}
/**
* Set the maximum number of seconds that this executor 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 executor won't wait for the termination of tasks at all.
* It will either shut down immediately, interrupting ongoing tasks and clearing
* the remaining task queue - or, if the
* {@link #setWaitForTasksToCompleteOnShutdown "waitForTasksToCompleteOnShutdown"}
* flag has been set to {@code true}, 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.
* <p>In either case, if you specify an await-termination period using this property,
* this executor will wait for the given time (max) for the termination of tasks.
* As a rule of thumb, specify a significantly higher timeout here if you set
* "waitForTasksToCompleteOnShutdown" to {@code true} at the same time,
* since all remaining tasks in the queue will still get executed - in contrast
* to the default shutdown behavior where it's just about waiting for currently
* executing tasks that aren't reacting to thread interruption.
* @see java.util.concurrent.ExecutorService#shutdown()
* @see java.util.concurrent.ExecutorService#awaitTermination
*/
public void setAwaitTerminationSeconds(int awaitTerminationSeconds) {
this.awaitTerminationSeconds = awaitTerminationSeconds;
}
@Override
public void setBeanName(String name) {
this.beanName = name;
}
/**
* Calls {@code initialize()} after the container applied all property values.
* @see #initialize()
*/
@Override
public void afterPropertiesSet() {
initialize();
}
/**
* Set up the ExecutorService.
*/
public void initialize() {
if (logger.isInfoEnabled()) {
logger.info("Initializing ExecutorService " + (this.beanName != null ? " '" + this.beanName + "'" : ""));
}
if (!this.threadNamePrefixSet && this.beanName != null) {
setThreadNamePrefix(this.beanName + "-");
}
this.executor = initializeExecutor(this.threadFactory, this.rejectedExecutionHandler);
}
/**
* Create the target {@link java.util.concurrent.ExecutorService} instance.
* Called by {@code afterPropertiesSet}.
* @param threadFactory the ThreadFactory to use
* @param rejectedExecutionHandler the RejectedExecutionHandler to use
* @return a new ExecutorService instance
* @see #afterPropertiesSet()
*/
protected abstract ExecutorService initializeExecutor(
ThreadFactory threadFactory, RejectedExecutionHandler rejectedExecutionHandler);
/**
* Calls {@code shutdown} when the BeanFactory destroys
* the task executor instance.
* @see #shutdown()
*/
@Override
public void destroy() {
shutdown();
}
/**
* Perform a shutdown on the underlying ExecutorService.
* @see java.util.concurrent.ExecutorService#shutdown()
* @see java.util.concurrent.ExecutorService#shutdownNow()
* @see #awaitTerminationIfNecessary()
*/
public void shutdown() {
if (logger.isInfoEnabled()) {
logger.info("Shutting down ExecutorService" + (this.beanName != null ? " '" + this.beanName + "'" : ""));
}
if (this.waitForTasksToCompleteOnShutdown) {
this.executor.shutdown();
}
else {
this.executor.shutdownNow();
}
awaitTerminationIfNecessary();
}
/**
* Wait for the executor to terminate, according to the value of the
* {@link #setAwaitTerminationSeconds "awaitTerminationSeconds"} property.
*/
private void awaitTerminationIfNecessary() {
if (this.awaitTerminationSeconds > 0) {
try {
if (!this.executor.awaitTermination(this.awaitTerminationSeconds, TimeUnit.SECONDS)) {
if (logger.isWarnEnabled()) {
logger.warn("Timed out while waiting for executor" +
(this.beanName != null ? " '" + this.beanName + "'" : "") + " to terminate");
}
}
}
catch (InterruptedException ex) {
if (logger.isWarnEnabled()) {
logger.warn("Interrupted while waiting for executor" +
(this.beanName != null ? " '" + this.beanName + "'" : "") + " to terminate");
}
Thread.currentThread().interrupt();
}
}
}
}