/* * Copyright 2002-2008 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.BlockingQueue; import java.util.concurrent.Executor; import java.util.concurrent.LinkedBlockingQueue; import java.util.concurrent.RejectedExecutionException; import java.util.concurrent.RejectedExecutionHandler; import java.util.concurrent.SynchronousQueue; 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; import org.springframework.core.task.TaskRejectedException; import org.springframework.scheduling.SchedulingTaskExecutor; import org.springframework.util.Assert; /** * JavaBean that allows for configuring a JDK 1.5 {@link java.util.concurrent.ThreadPoolExecutor} * in bean style (through its "corePoolSize", "maxPoolSize", "keepAliveSeconds", "queueCapacity" * properties), exposing it as a Spring {@link org.springframework.core.task.TaskExecutor}. * This is an alternative to configuring a ThreadPoolExecutor instance directly using * constructor injection, with a separate {@link ConcurrentTaskExecutor} adapter wrapping it. * *
For any custom needs, in particular for defining a * {@link java.util.concurrent.ScheduledThreadPoolExecutor}, it is recommended to * use a straight definition of the Executor instance or a factory method definition * that points to the JDK 1.5 {@link java.util.concurrent.Executors} class. * To expose such a raw Executor as a Spring {@link org.springframework.core.task.TaskExecutor}, * simply wrap it with a {@link ConcurrentTaskExecutor} adapter. * *
NOTE: This class implements Spring's * {@link org.springframework.core.task.TaskExecutor} interface as well as the JDK 1.5 * {@link java.util.concurrent.Executor} interface, with the former being the primary * interface, the other just serving as secondary convenience. For this reason, the * exception handling follows the TaskExecutor contract rather than the Executor contract, * in particular regarding the {@link org.springframework.core.task.TaskRejectedException}. * * @author Juergen Hoeller * @since 2.0 * @see org.springframework.core.task.TaskExecutor * @see java.util.concurrent.Executor * @see java.util.concurrent.ThreadPoolExecutor * @see java.util.concurrent.ScheduledThreadPoolExecutor * @see java.util.concurrent.Executors * @see ConcurrentTaskExecutor */ public class ThreadPoolTaskExecutor extends CustomizableThreadFactory implements SchedulingTaskExecutor, Executor, BeanNameAware, InitializingBean, DisposableBean { protected final Log logger = LogFactory.getLog(getClass()); private final Object poolSizeMonitor = new Object(); private int corePoolSize = 1; private int maxPoolSize = Integer.MAX_VALUE; private int keepAliveSeconds = 60; private boolean allowCoreThreadTimeOut = false; private int queueCapacity = Integer.MAX_VALUE; private ThreadFactory threadFactory = this; private RejectedExecutionHandler rejectedExecutionHandler = new ThreadPoolExecutor.AbortPolicy(); private boolean waitForTasksToCompleteOnShutdown = false; private boolean threadNamePrefixSet = false; private String beanName; private ThreadPoolExecutor threadPoolExecutor; /** * Set the ThreadPoolExecutor's core pool size. * Default is 1. *
This setting can be modified at runtime, for example through JMX.
*/
public void setCorePoolSize(int corePoolSize) {
synchronized (this.poolSizeMonitor) {
this.corePoolSize = corePoolSize;
if (this.threadPoolExecutor != null) {
this.threadPoolExecutor.setCorePoolSize(corePoolSize);
}
}
}
/**
* Return the ThreadPoolExecutor's core pool size.
*/
public int getCorePoolSize() {
synchronized (this.poolSizeMonitor) {
return this.corePoolSize;
}
}
/**
* Set the ThreadPoolExecutor's maximum pool size.
* Default is Integer.MAX_VALUE
.
*
This setting can be modified at runtime, for example through JMX. */ public void setMaxPoolSize(int maxPoolSize) { synchronized (this.poolSizeMonitor) { this.maxPoolSize = maxPoolSize; if (this.threadPoolExecutor != null) { this.threadPoolExecutor.setMaximumPoolSize(maxPoolSize); } } } /** * Return the ThreadPoolExecutor's maximum pool size. */ public int getMaxPoolSize() { synchronized (this.poolSizeMonitor) { return this.maxPoolSize; } } /** * Set the ThreadPoolExecutor's keep-alive seconds. * Default is 60. *
This setting can be modified at runtime, for example through JMX. */ public void setKeepAliveSeconds(int keepAliveSeconds) { synchronized (this.poolSizeMonitor) { this.keepAliveSeconds = keepAliveSeconds; if (this.threadPoolExecutor != null) { this.threadPoolExecutor.setKeepAliveTime(keepAliveSeconds, TimeUnit.SECONDS); } } } /** * Return the ThreadPoolExecutor's keep-alive seconds. */ public int getKeepAliveSeconds() { synchronized (this.poolSizeMonitor) { return this.keepAliveSeconds; } } /** * Specify whether to allow core threads to time out. This enables dynamic * growing and shrinking even in combination with a non-zero queue (since * the max pool size will only grow once the queue is full). *
Default is "false". Note that this feature is only available on Java 6
* or above. On Java 5, consider switching to the backport-concurrent
* version of ThreadPoolTaskExecutor which also supports this feature.
* @see java.util.concurrent.ThreadPoolExecutor#allowCoreThreadTimeOut(boolean)
*/
public void setAllowCoreThreadTimeOut(boolean allowCoreThreadTimeOut) {
this.allowCoreThreadTimeOut = allowCoreThreadTimeOut;
}
/**
* Set the capacity for the ThreadPoolExecutor's BlockingQueue.
* Default is Integer.MAX_VALUE
.
*
Any positive value will lead to a LinkedBlockingQueue instance; * any other value will lead to a SynchronousQueue instance. * @see java.util.concurrent.LinkedBlockingQueue * @see java.util.concurrent.SynchronousQueue */ public void setQueueCapacity(int queueCapacity) { this.queueCapacity = queueCapacity; } /** * Set the ThreadFactory to use for the ThreadPoolExecutor's thread pool. *
Default is this executor itself (i.e. the factory that this executor * inherits from). See {@link org.springframework.util.CustomizableThreadCreator}'s * javadoc for available bean properties. * @see #setThreadPriority * @see #setDaemon */ public void setThreadFactory(ThreadFactory threadFactory) { this.threadFactory = (threadFactory != null ? threadFactory : this); } /** * Set the RejectedExecutionHandler to use for the ThreadPoolExecutor. * Default is the ThreadPoolExecutor'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. *
Default is "false". Switch this to "true" if you prefer
* fully completed tasks at the expense of a longer shutdown phase.
* @see java.util.concurrent.ThreadPoolExecutor#shutdown()
* @see java.util.concurrent.ThreadPoolExecutor#shutdownNow()
*/
public void setWaitForTasksToCompleteOnShutdown(boolean waitForJobsToCompleteOnShutdown) {
this.waitForTasksToCompleteOnShutdown = waitForJobsToCompleteOnShutdown;
}
@Override
public void setThreadNamePrefix(String threadNamePrefix) {
super.setThreadNamePrefix(threadNamePrefix);
this.threadNamePrefixSet = true;
}
public void setBeanName(String name) {
this.beanName = name;
}
/**
* Calls initialize()
after the container applied all property values.
* @see #initialize()
*/
public void afterPropertiesSet() {
initialize();
}
/**
* Creates the BlockingQueue and the ThreadPoolExecutor.
* @see #createQueue
*/
public void initialize() {
if (logger.isInfoEnabled()) {
logger.info("Initializing ThreadPoolExecutor" + (this.beanName != null ? " '" + this.beanName + "'" : ""));
}
if (!this.threadNamePrefixSet && this.beanName != null) {
setThreadNamePrefix(this.beanName + "-");
}
BlockingQueue queue = createQueue(this.queueCapacity);
this.threadPoolExecutor = new ThreadPoolExecutor(
this.corePoolSize, this.maxPoolSize, this.keepAliveSeconds, TimeUnit.SECONDS,
queue, this.threadFactory, this.rejectedExecutionHandler);
if (this.allowCoreThreadTimeOut) {
this.threadPoolExecutor.allowCoreThreadTimeOut(true);
}
}
/**
* Create the BlockingQueue to use for the ThreadPoolExecutor.
*
A LinkedBlockingQueue instance will be created for a positive
* capacity value; a SynchronousQueue else.
* @param queueCapacity the specified queue capacity
* @return the BlockingQueue instance
* @see java.util.concurrent.LinkedBlockingQueue
* @see java.util.concurrent.SynchronousQueue
*/
protected BlockingQueue createQueue(int queueCapacity) {
if (queueCapacity > 0) {
return new LinkedBlockingQueue(queueCapacity);
}
else {
return new SynchronousQueue();
}
}
/**
* Return the underlying ThreadPoolExecutor for native access.
* @return the underlying ThreadPoolExecutor (never null
)
* @throws IllegalStateException if the ThreadPoolTaskExecutor hasn't been initialized yet
*/
public ThreadPoolExecutor getThreadPoolExecutor() throws IllegalStateException {
Assert.state(this.threadPoolExecutor != null, "ThreadPoolTaskExecutor not initialized");
return this.threadPoolExecutor;
}
/**
* Implementation of both the JDK 1.5 Executor interface and the Spring
* TaskExecutor interface, delegating to the ThreadPoolExecutor instance.
* @see java.util.concurrent.Executor#execute(Runnable)
* @see org.springframework.core.task.TaskExecutor#execute(Runnable)
*/
public void execute(Runnable task) {
Executor executor = getThreadPoolExecutor();
try {
executor.execute(task);
}
catch (RejectedExecutionException ex) {
throw new TaskRejectedException("Executor [" + executor + "] did not accept task: " + task, ex);
}
}
/**
* This task executor prefers short-lived work units.
*/
public boolean prefersShortLivedTasks() {
return true;
}
/**
* Return the current pool size.
* @see java.util.concurrent.ThreadPoolExecutor#getPoolSize()
*/
public int getPoolSize() {
return getThreadPoolExecutor().getPoolSize();
}
/**
* Return the number of currently active threads.
* @see java.util.concurrent.ThreadPoolExecutor#getActiveCount()
*/
public int getActiveCount() {
return getThreadPoolExecutor().getActiveCount();
}
/**
* Calls shutdown
when the BeanFactory destroys
* the task executor instance.
* @see #shutdown()
*/
public void destroy() {
shutdown();
}
/**
* Perform a shutdown on the ThreadPoolExecutor.
* @see java.util.concurrent.ThreadPoolExecutor#shutdown()
*/
public void shutdown() {
if (logger.isInfoEnabled()) {
logger.info("Shutting down ThreadPoolExecutor" + (this.beanName != null ? " '" + this.beanName + "'" : ""));
}
if (this.waitForTasksToCompleteOnShutdown) {
this.threadPoolExecutor.shutdown();
}
else {
this.threadPoolExecutor.shutdownNow();
}
}
}