| /* |
| * Copyright 2013-present Facebook, Inc. |
| * |
| * Licensed 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 com.facebook.buck.util.concurrent; |
| |
| import java.util.concurrent.ExecutorService; |
| import java.util.concurrent.Executors; |
| import java.util.concurrent.LinkedBlockingQueue; |
| import java.util.concurrent.ThreadFactory; |
| import java.util.concurrent.ThreadPoolExecutor; |
| import java.util.concurrent.TimeUnit; |
| import java.util.concurrent.atomic.AtomicInteger; |
| |
| public class MoreExecutors { |
| |
| private MoreExecutors() { |
| // Utility class. |
| } |
| |
| /** |
| * A ThreadFactory which gives each thread a meaningful and distinct name. |
| * ThreadFactoryBuilder is not used to avoid a dependency on Guava in the junit target. |
| */ |
| public static class NamedThreadFactory implements ThreadFactory { |
| |
| private final AtomicInteger threadCount = new AtomicInteger(0); |
| private final String threadName; |
| |
| public NamedThreadFactory(String threadName) { |
| this.threadName = threadName; |
| } |
| |
| @Override |
| public Thread newThread(Runnable r) { |
| Thread newThread = Executors.defaultThreadFactory().newThread(r); |
| newThread.setName(String.format(threadName + "-%d", threadCount.incrementAndGet())); |
| return newThread; |
| } |
| } |
| |
| /** |
| * Creates a single threaded executor that silently discards rejected tasks. The problem with |
| * {@link java.util.concurrent.Executors#newSingleThreadExecutor()} is that it does not let us |
| * specify a RejectedExecutionHandler, which we need to ensure that garbage is not spewed to the |
| * user's console if the build fails. |
| * |
| * @return A single-threaded executor that silently discards rejected tasks. |
| * @param threadName a thread name prefix used to easily identify threads when debugging. |
| */ |
| public static ExecutorService newSingleThreadExecutor(final String threadName) { |
| return newSingleThreadExecutor(new NamedThreadFactory(threadName)); |
| } |
| |
| public static ExecutorService newSingleThreadExecutor(ThreadFactory threadFactory) { |
| return new ThreadPoolExecutor( |
| /* corePoolSize */ 1, |
| /* maximumPoolSize */ 1, |
| /* keepAliveTime */ 0L, TimeUnit.MILLISECONDS, |
| /* workQueue */ new LinkedBlockingQueue<Runnable>(), |
| /* threadFactory */ threadFactory, |
| /* handler */ new ThreadPoolExecutor.DiscardPolicy()); |
| } |
| |
| /** |
| * Creates a multi-threaded executor with meaningfully named threads. |
| * @param threadName a thread name prefix used to easily identify threads when debugging. |
| * @param count the number of threads that should be created in the pool. |
| * @return A multi-threaded executor. |
| */ |
| public static ExecutorService newMultiThreadExecutor(final String threadName, int count) { |
| return newMultiThreadExecutor(new NamedThreadFactory(threadName), count); |
| } |
| |
| public static ExecutorService newMultiThreadExecutor(ThreadFactory threadFactory, int count) { |
| return new ThreadPoolExecutor( |
| /* corePoolSize */ count, |
| /* maximumPoolSize */ count, |
| /* keepAliveTime */ 0L, TimeUnit.MILLISECONDS, |
| /* workQueue */ new LinkedBlockingQueue<Runnable>(), |
| /* threadFactory */ threadFactory, |
| /* handler */ new ThreadPoolExecutor.DiscardPolicy()); |
| } |
| |
| /** |
| * Shutdown {@code service} and wait for all it's tasks to terminate. In the event of |
| * {@link InterruptedException}, propagate the interrupt to all tasks, wait for them to |
| * finish, then re-throw the exception. |
| */ |
| public static boolean shutdown( |
| ExecutorService service, |
| long timeout, |
| TimeUnit unit) throws InterruptedException { |
| service.shutdown(); |
| try { |
| return service.awaitTermination(timeout, unit); |
| } catch (InterruptedException e) { |
| service.shutdownNow(); |
| service.awaitTermination(timeout, unit); |
| throw e; |
| } |
| } |
| |
| public static void shutdown(ExecutorService service) throws InterruptedException { |
| shutdown(service, Long.MAX_VALUE, TimeUnit.DAYS); |
| } |
| |
| /** |
| * Cancel the processing being carried out by the given service and waits for the processing to |
| * complete. If processing has still not terminated the method throws the given exception. |
| */ |
| public static void shutdownOrThrow( |
| ExecutorService service, |
| long timeout, |
| TimeUnit unit, |
| RuntimeException exception) { |
| boolean terminated = false; |
| service.shutdown(); |
| try { |
| terminated = service.awaitTermination(timeout, unit); |
| } catch (InterruptedException e) { |
| terminated = false; |
| } finally { |
| if (!terminated) { |
| service.shutdownNow(); |
| try { |
| terminated = service.awaitTermination(timeout, unit); |
| } catch (InterruptedException e) { |
| terminated = false; |
| } |
| } |
| } |
| if (!terminated) { |
| throw exception; |
| } |
| } |
| } |