org.danilopianini.concurrency.FastReadWriteLock Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of javalib-java7 Show documentation

Handful shortcuts for Java programming, Java 7 compatible.

There is a newer version: 0.6.1

/*******************************************************************************
 * Copyright (C) 2009, 2015, Danilo Pianini and contributors
 * listed in the project's build.gradle or pom.xml file.
 *
 * This file is distributed under the terms of the Apache License, version 2.0
 *******************************************************************************/
package org.danilopianini.concurrency;

import java.util.concurrent.Semaphore;

/**
 * This class implements a non-reentrant ReadWriteLock.
 * 
 * @author Danilo Pianini
 * 
 */
public class FastReadWriteLock {

	private final Semaphore lock = new Semaphore(Integer.MAX_VALUE);

	/**
	 * Acquire a read lock. Blocks until a read lock is available
	 */
	public void read() {
		lock.acquireUninterruptibly();
	}

	/**
	 * Acquire a write lock. Blocks until a write lock is available
	 */
	public void write() {
		lock.acquireUninterruptibly(Integer.MAX_VALUE);
	}

	/**
	 * Signals that the operation is done.
	 */
	public void release() {
		if (lock.availablePermits() == 0) {
			lock.release(Integer.MAX_VALUE);
		} else {
			lock.release();
		}
	}
}