com.aspectran.core.util.thread.AutoLock Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2022 The Aspectran Project
*
* 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 com.aspectran.core.util.thread;
import java.io.Serializable;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.ReentrantLock;
/**
* Reentrant lock that can be used in a try-with-resources statement.
* Typical usage:
*
* try (AutoLock lock = this.lock.lock())
* {
* // Something
* }
*
*/
public class AutoLock implements AutoCloseable, Serializable {
private static final long serialVersionUID = -6052401301556858025L;
private final ReentrantLock lock = new ReentrantLock();
/**
* Acquires the lock.
* @return this AutoLock for unlocking
*/
public AutoLock lock() {
lock.lock();
return this;
}
/**
* @return whether this lock is held by the current thread
* @see ReentrantLock#isHeldByCurrentThread()
*/
public boolean isHeldByCurrentThread() {
return lock.isHeldByCurrentThread();
}
/**
* @return a {@link Condition} associated with this lock
*/
public Condition newCondition() {
return lock.newCondition();
}
// Package-private for testing only.
boolean isLocked() {
return lock.isLocked();
}
@Override
public void close() {
lock.unlock();
}
/**
* A reentrant lock with a condition that can be used in a try-with-resources statement.
* Typical usage:
*
* // Waiting
* try (AutoLock lock = _lock.lock())
* {
* lock.await();
* }
*
* // Signaling
* try (AutoLock lock = _lock.lock())
* {
* lock.signalAll();
* }
*
*/
public static class WithCondition extends AutoLock {
private final Condition condition = newCondition();
@Override
public AutoLock.WithCondition lock() {
return (WithCondition)super.lock();
}
/**
* @see Condition#signal()
*/
public void signal() {
condition.signal();
}
/**
* @see Condition#signalAll()
*/
public void signalAll() {
condition.signalAll();
}
/**
* @throws InterruptedException if the current thread is interrupted
* @see Condition#await()
*/
public void await() throws InterruptedException {
condition.await();
}
/**
* @param time the time to wait
* @param unit the time unit
* @return false if the waiting time elapsed
* @throws InterruptedException if the current thread is interrupted
* @see Condition#await(long, TimeUnit)
*/
public boolean await(long time, TimeUnit unit) throws InterruptedException {
return condition.await(time, unit);
}
}
}