rationals.utils.Barrier Maven / Gradle / Ivy
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/*______________________________________________________________________________
*
* Copyright 2005 Arnaud Bailly - NORSYS/LIFL
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* (1) Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* (2) Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* (3) The name of the author may not be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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*
* Created on 16 avr. 2005
*
*/
package rationals.utils;
/**
* A simple barrier.
*
* A barrier is initialized with a number. When a thread calls {@see #await()}
* on this barrier, a counter is decreased an the thread is blocked. When
* counter reaches 0, all threads waiting on the barrier are released.
*
* @author nono
* @version $Id: Barrier.java 2 2006-08-24 14:41:48Z oqube $
*/
public class Barrier {
private final int num;
private volatile int count;
public Barrier(int n) {
this.num = n;
this.count = num;
}
public synchronized void await() {
count--;
if (count == 0) {
this.notifyAll();
count = num;
} else
try {
this.wait();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}