| /* |
| * 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.slider.server.services.utility; |
| |
| import org.apache.hadoop.service.Service; |
| import org.apache.hadoop.service.ServiceStateChangeListener; |
| |
| import java.util.concurrent.TimeoutException; |
| import java.util.concurrent.atomic.AtomicBoolean; |
| |
| /** |
| * Wait for a service to stop. |
| * |
| * WARNING: the notification may come in as soon as the service enters |
| * the stopped state: it may take some time for the actual stop operation |
| * to complete. |
| */ |
| public class EndOfServiceWaiter implements ServiceStateChangeListener { |
| |
| private final AtomicBoolean finished = new AtomicBoolean(false); |
| private final String name; |
| |
| /** |
| * Wait for a service; use the service name as this instance's name |
| * @param service service |
| */ |
| public EndOfServiceWaiter(Service service) { |
| this(service.getName(), service); |
| } |
| |
| |
| /** |
| * Wait for a service |
| * @param name name for messages |
| * @param service service |
| */ |
| public EndOfServiceWaiter(String name, Service service) { |
| this.name = name; |
| service.registerServiceListener(this); |
| } |
| |
| public synchronized void waitForServiceToStop(long timeout) throws |
| InterruptedException, TimeoutException { |
| if (!finished.get()) { |
| wait(timeout); |
| } |
| if (!finished.get()) { |
| throw new TimeoutException(name |
| + " did not finish after " + timeout + |
| " milliseconds"); |
| } |
| } |
| |
| /** |
| * Wait for service state change callbacks; notify self if the service has |
| * now stopped |
| * @param service service |
| */ |
| @Override |
| public synchronized void stateChanged(Service service) { |
| if (service.isInState(Service.STATE.STOPPED)) { |
| finished.set(true); |
| notify(); |
| } |
| } |
| |
| |
| } |