/*
* 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.flink.runtime.iterative.concurrent;
import java.util.concurrent.CountDownLatch;
import org.apache.flink.runtime.event.task.AbstractTaskEvent;
import org.apache.flink.runtime.event.task.EventListener;
import org.apache.flink.runtime.iterative.event.AllWorkersDoneEvent;
import org.apache.flink.runtime.iterative.event.TerminationEvent;
import org.apache.flink.types.Value;
/**
* A resettable one-shot latch.
*/
public class SuperstepBarrier implements EventListener {
private final ClassLoader userCodeClassLoader;
private boolean terminationSignaled = false;
private CountDownLatch latch;
private String[] aggregatorNames;
private Value[] aggregates;
public SuperstepBarrier(ClassLoader userCodeClassLoader) {
this.userCodeClassLoader = userCodeClassLoader;
}
/** setup the barrier, has to be called at the beginning of each superstep */
public void setup() {
latch = new CountDownLatch(1);
}
/** wait on the barrier */
public void waitForOtherWorkers() throws InterruptedException {
latch.await();
}
public String[] getAggregatorNames() {
return aggregatorNames;
}
public Value[] getAggregates() {
return aggregates;
}
/** barrier will release the waiting thread if an event occurs */
@Override
public void eventOccurred(AbstractTaskEvent event) {
if (event instanceof TerminationEvent) {
terminationSignaled = true;
}
else if (event instanceof AllWorkersDoneEvent) {
AllWorkersDoneEvent wde = (AllWorkersDoneEvent) event;
aggregatorNames = wde.getAggregatorNames();
aggregates = wde.getAggregates(userCodeClassLoader);
}
else {
throw new IllegalArgumentException("Unknown event type.");
}
latch.countDown();
}
public boolean terminationSignaled() {
return terminationSignaled;
}
}