/*
* 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.io.network.util;
import org.apache.flink.runtime.util.event.NotificationListener;
import java.util.concurrent.atomic.AtomicInteger;
/**
* A mock notification listener.
*/
public class TestNotificationListener implements NotificationListener {
final AtomicInteger numberOfNotifications = new AtomicInteger();
@Override
public void onNotification() {
synchronized (numberOfNotifications) {
numberOfNotifications.incrementAndGet();
numberOfNotifications.notifyAll();
}
}
/**
* Waits on a notification.
*
* <p> <strong>Important</strong>: It's necessary to get the current number of notifications
* <em>before</em> registering the listener. Otherwise the wait call may block indefinitely.
*
* <pre>
* MockNotificationListener listener = new MockNotificationListener();
*
* int current = listener.getNumberOfNotifications();
*
* // Register the listener
* register(listener);
*
* listener.waitForNotification(current);
* </pre>
*/
public void waitForNotification(int current) throws InterruptedException {
synchronized (numberOfNotifications) {
while (current == numberOfNotifications.get()) {
numberOfNotifications.wait();
}
}
}
public int getNumberOfNotifications() {
return numberOfNotifications.get();
}
public void reset() {
numberOfNotifications.set(0);
}
}