net.schmizz.concurrent.Event Maven / Gradle / Ivy
/*
* Copyright 2010 Shikhar Bhushan
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package net.schmizz.concurrent;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.ReentrantLock;
/*
* Syntactic sugar around Future
*/
/**
* A kind of {@link Future} that caters to boolean values.
*
* An event can be set, cleared, or awaited, similar to Python's {@code threading.event}. The key difference is that a
* waiter may be delivered an exception of parameterized type {@code T}. Furthermore, an event {@link #isSet()} when it
* is not {@code null} i.e. it can be either {@code true} or {@code false} when set.
*
* @see Future
*/
public class Event
extends Future {
/**
* Creates this event with given {@code name} and exception {@code chainer}. Allocates a new {@link
* java.util.concurrent.locks.Lock Lock} object for this event.
*
* @param name name of this event
* @param chainer {@link ExceptionChainer} that will be used for chaining exceptions
*/
public Event(String name, ExceptionChainer chainer) {
super(name, chainer);
}
/**
* Creates this event with given {@code name}, exception {@code chainer}, and associated {@code lock}.
*
* @param name name of this event
* @param chainer {@link ExceptionChainer} that will be used for chaining exceptions
* @param lock lock to use
*/
public Event(String name, ExceptionChainer chainer, ReentrantLock lock) {
super(name, chainer, lock);
}
/** Sets this event to be {@code true}. Short for {@code set(true)}. */
public void set() {
super.set(true);
}
/**
* Await this event to have a definite {@code true} or {@code false} value.
*
* @throws T if another thread meanwhile informs this event of an error
*/
public void await()
throws T {
super.get();
}
/**
* Await this event to have a definite {@code true} or {@code false} value, for {@code timeout} duration.
*
* @param timeout timeout
* @param unit the time unit for the timeout
*
* @throws T if another thread meanwhile informs this event of an error, or timeout expires
*/
public void await(long timeout, TimeUnit unit)
throws T {
super.get(timeout, unit);
}
}