org.apache.ratis.util.AwaitForSignal Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.ratis.util;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicReference;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
/**
* This class is a partial implementation of {@link java.util.concurrent.locks.Condition}.
* Only some of the await and signal methods are implemented.
*
* This class is threadsafe.
*/
public class AwaitForSignal {
private final String name;
private final Lock lock = new ReentrantLock();
private final Condition condition = lock.newCondition();
private final AtomicReference signaled = new AtomicReference<>(new AtomicBoolean());
public AwaitForSignal(Object name) {
this.name = name + "-" + JavaUtils.getClassSimpleName(getClass());
}
/** The same as {@link java.util.concurrent.locks.Condition#await()} */
public void await() throws InterruptedException {
lock.lock();
try {
for (final AtomicBoolean s = signaled.get(); !s.get(); ) {
condition.await();
}
} finally {
lock.unlock();
}
}
/** The same as {@link java.util.concurrent.locks.Condition#await(long, TimeUnit)} */
public boolean await(long time, TimeUnit unit) throws InterruptedException {
if (time <= 0) {
return false;
}
lock.lock();
try {
if (signaled.get().get()) {
return true;
}
return condition.await(time, unit);
} finally {
lock.unlock();
}
}
/** The same as {@link java.util.concurrent.locks.Condition#signal()} */
public void signal() {
lock.lock();
try {
signaled.getAndSet(new AtomicBoolean()).set(true);
condition.signalAll();
} finally {
lock.unlock();
}
}
@Override
public String toString() {
return name;
}
}