org.springframework.scheduling.concurrent.ExecutorLifecycleDelegate Maven / Gradle / Ivy
/*
* Copyright 2002-2024 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
*
* https://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.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import org.springframework.context.SmartLifecycle;
import org.springframework.lang.Nullable;
/**
* An internal delegate for common {@link ExecutorService} lifecycle management
* with pause/resume support.
*
* @author Juergen Hoeller
* @since 6.1
* @see ExecutorConfigurationSupport
* @see SimpleAsyncTaskScheduler
*/
final class ExecutorLifecycleDelegate implements SmartLifecycle {
private final ExecutorService executor;
private final Lock pauseLock = new ReentrantLock();
private final Condition unpaused = this.pauseLock.newCondition();
private volatile boolean paused;
private volatile boolean shutdown;
private int executingTaskCount = 0;
@Nullable
private Runnable stopCallback;
public ExecutorLifecycleDelegate(ExecutorService executor) {
this.executor = executor;
}
@Override
public void start() {
this.pauseLock.lock();
try {
this.paused = false;
this.unpaused.signalAll();
}
finally {
this.pauseLock.unlock();
}
}
@Override
public void stop() {
this.pauseLock.lock();
try {
this.paused = true;
this.stopCallback = null;
}
finally {
this.pauseLock.unlock();
}
}
@Override
public void stop(Runnable callback) {
this.pauseLock.lock();
try {
this.paused = true;
if (this.executingTaskCount == 0) {
this.stopCallback = null;
callback.run();
}
else {
this.stopCallback = callback;
}
}
finally {
this.pauseLock.unlock();
}
}
@Override
public boolean isRunning() {
return (!this.paused && !this.executor.isTerminated());
}
void markShutdown() {
this.shutdown = true;
}
void beforeExecute(Thread thread) {
this.pauseLock.lock();
try {
while (this.paused && !this.shutdown && !this.executor.isShutdown()) {
this.unpaused.await();
}
}
catch (InterruptedException ex) {
thread.interrupt();
}
finally {
this.executingTaskCount++;
this.pauseLock.unlock();
}
}
void afterExecute() {
this.pauseLock.lock();
try {
this.executingTaskCount--;
if (this.executingTaskCount == 0) {
Runnable callback = this.stopCallback;
if (callback != null) {
callback.run();
this.stopCallback = null;
}
}
}
finally {
this.pauseLock.unlock();
}
}
}