/*
* 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;
public class SuperstepKickoffLatch {
private final Object monitor = new Object();
private int superstepNumber = 1;
private boolean terminated;
public void triggerNextSuperstep() {
synchronized (monitor) {
if (terminated) {
throw new IllegalStateException("Already terminated.");
}
superstepNumber++;
monitor.notifyAll();
}
}
public void signalTermination() {
synchronized (monitor) {
terminated = true;
monitor.notifyAll();
}
}
public boolean awaitStartOfSuperstepOrTermination(int superstep) throws InterruptedException {
while (true) {
synchronized (monitor) {
if (terminated) {
return true;
}
else if (superstepNumber == superstep) {
// reached the superstep. all good!
return false;
}
else if (superstepNumber == superstep - 1) {
monitor.wait(2000);
}
else {
throw new IllegalStateException("Error while waiting for start of next superstep. current= " + superstepNumber + " waitingFor=" + superstep);
}
}
}
}
}