/*
* Copyright (c) 2003, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/*
* @bug 4530538
* @summary A semaphore utility class.
* @author Mandy Chung
*/
public class Semaphore {
private Object go = new Object();
private int semaCount;
private int waiters = 0;
public Semaphore() {
semaCount = 0;
}
public Semaphore(int initialCount) {
semaCount = initialCount;
}
public void semaP() {
synchronized (go) {
waiters++;
while (semaCount == 0) {
try {
go.wait();
} catch (InterruptedException e) {
e.printStackTrace();
throw new InternalError();
}
}
semaCount--;
waiters--;
}
}
public void semaV() {
synchronized (go) {
semaCount++;
go.notify();
}
}
public int getWaiterCount() {
synchronized (go) {
return waiters;
}
}
public Object getLock() {
return go;
}
}