org.danilopianini.concurrency.ThreadLocalIdGenerator 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.io.Serializable;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * 
 * This class provides an id generator local to threads.
 * 
 * @author Danilo Pianini
 * 
 */
public final class ThreadLocalIdGenerator implements Serializable {

	private static final long serialVersionUID = 4130571136157694474L;
	private static final Singleton SINGLETON = new Singleton();

	private static final class Singleton extends ThreadLocal implements Serializable {
		private static final long serialVersionUID = -4638200973190990225L;

		@Override
		protected AtomicInteger initialValue() {
			return new AtomicInteger(0);
		}
	}

	/**
	 * @return a freshly generated id. Thread-local.
	 */
	public int genId() {
		return SINGLETON.get().getAndIncrement();
	}

}