Mega Code Archive
Count Up Down Latch
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/* Copyright (c) 2001-2009, The HSQL Development Group
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 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.
*
* Neither the name of the HSQL Development Group nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 HSQL DEVELOPMENT GROUP, HSQLDB.ORG,
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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*/
import java.util.concurrent.CountDownLatch;
public class CountUpDownLatch {
CountDownLatch latch;
int count;
public CountUpDownLatch() {
latch = new CountDownLatch(1);
this.count = count;
}
public void await() throws InterruptedException {
if (count == 0) {
return;
}
latch.await();
}
public void countDown() {
count--;
if (count == 0) {
latch.countDown();
}
}
public long getCount() {
return count;
}
public void countUp() {
if (latch.getCount() == 0) {
latch = new CountDownLatch(1);
}
count++;
}
public void setCount(int count) {
if (count == 0) {
if (latch.getCount() != 0) {
latch.countDown();
}
} else if (latch.getCount() == 0) {
latch = new CountDownLatch(1);
}
this.count = count;
}
}
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