/**
* Copyright (c) 2013, Will Szumski
*
* This file is part of formicidae.
*
* formicidae is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* formicidae 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 for more details.
*
* You should have received a copy of the GNU General Public License
* along with formicidae. If not, see <http://www.gnu.org/licenses/>.
*/
package org.cowboycoders.ant.events;
import java.util.concurrent.Callable;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.locks.Lock;
import java.util.logging.Logger;
public class LockExchanger implements Callable<Lock> {
private TimeUnit timeoutUnit;
private long timeout;
private LockExchangeContainer container;
public final static Logger LOGGER = Logger.getLogger(EventMachine.class .getName());
public LockExchanger(LockExchangeContainer container, long timeout, TimeUnit unit) {
this.timeout = timeout;
this.timeoutUnit = unit;
this.container = container;
}
@Override
public Lock call() throws InterruptedException, TimeoutException {
try {
container.lock.lock();
final long timeoutNano = TimeUnit.NANOSECONDS.convert(timeout, timeoutUnit);
final long initialTimeStamp = System.nanoTime();
while (container.returnLock == null) {
long timeoutRemaining = timeoutNano - (System.nanoTime() - initialTimeStamp);
if(!(container.lockAvailable.await(timeoutRemaining,TimeUnit.NANOSECONDS))) {
throw new TimeoutException("timeout waiting for exchanged lock");
}
}
LOGGER.finer("call() - returning");
return container.returnLock;
} finally {
container.lock.unlock();
}
}
}