| /* |
| * 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.workflow; |
| |
| import org.apache.hadoop.service.AbstractService; |
| |
| import java.util.concurrent.Callable; |
| import java.util.concurrent.ExecutorService; |
| import java.util.concurrent.Future; |
| |
| /** |
| * A service that hosts an executor -when the service is stopped, |
| * {@link ExecutorService#shutdownNow()} is invoked. |
| */ |
| public abstract class AbstractWorkflowExecutorService extends AbstractService { |
| |
| private ExecutorService executor; |
| |
| /** |
| * Construct an instance with the given name -but |
| * no executor |
| * @param name service name |
| */ |
| public AbstractWorkflowExecutorService(String name) { |
| this(name, null); |
| } |
| |
| /** |
| * Construct an instance with the given name and executor |
| * @param name service name |
| * @param executor exectuor |
| */ |
| protected AbstractWorkflowExecutorService(String name, |
| ExecutorService executor) { |
| super(name); |
| this.executor = executor; |
| } |
| |
| /** |
| * Get the executor |
| * @return the executor |
| */ |
| public synchronized ExecutorService getExecutor() { |
| return executor; |
| } |
| |
| /** |
| * Set the executor. This is protected as it |
| * is intended to be restricted to subclasses |
| * @param executor executor |
| */ |
| protected synchronized void setExecutor(ExecutorService executor) { |
| this.executor = executor; |
| } |
| |
| /** |
| * Execute the runnable with the executor (which |
| * must have been created already) |
| * @param runnable runnable to execute |
| */ |
| public void execute(Runnable runnable) { |
| getExecutor().execute(runnable); |
| } |
| |
| /** |
| * Submit a callable |
| * @param callable callable |
| * @param <V> type of the final get |
| * @return a future to wait on |
| */ |
| public <V> Future<V> submit(Callable<V> callable) { |
| return getExecutor().submit(callable); |
| } |
| /** |
| * Stop the service: halt the executor. |
| * @throws Exception exception. |
| */ |
| @Override |
| protected void serviceStop() throws Exception { |
| super.serviceStop(); |
| stopExecutor(); |
| } |
| |
| /** |
| * Stop the executor if it is not null. |
| * This uses {@link ExecutorService#shutdownNow()} |
| * and so does not block until they have completed. |
| */ |
| protected synchronized void stopExecutor() { |
| if (executor != null) { |
| executor.shutdownNow(); |
| } |
| } |
| } |