com.diozero.util.Event Maven / Gradle / Ivy
package com.diozero.util;
/*
* #%L
* Organisation: mattjlewis
* Project: Device I/O Zero - Core
* Filename: Event.java
*
* This file is part of the diozero project. More information about this project
* can be found at http://www.diozero.com/
* %%
* Copyright (C) 2016 - 2017 mattjlewis
* %%
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
* #L%
*/
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
public class Event {
private Lock lock = new ReentrantLock();
private Condition cond = lock.newCondition();
private boolean wasSet;
/**
* Wait indefinitely for set() to be called.
* @return True if set() was called, false woken unexpectedly.
* @throws InterruptedException If interrupted.
*/
public boolean doWait() throws InterruptedException {
lock.lock();
wasSet = false;
try {
cond.await();
} finally {
lock.unlock();
}
return wasSet;
}
/**
* Wait the specified time period for set() to be called.
* @param timeout Timeout value in milliseconds.
* @return True if set() was called, false if timed out waiting.
* @throws InterruptedException If interrupted.
*/
public boolean doWait(int timeout) throws InterruptedException {
lock.lock();
wasSet = false;
try {
cond.await(timeout, TimeUnit.MILLISECONDS);
} finally {
lock.unlock();
}
return wasSet;
}
public void set() {
lock.lock();
wasSet = true;
try {
cond.signalAll();
} finally {
lock.unlock();
}
}
public void clear() {
lock.lock();
wasSet = false;
try {
cond.signalAll();
} finally {
lock.unlock();
}
}
}