| /* |
| * Copyright (C) 2016 The Android Open Source Project |
| * |
| * 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.android.internal.util; |
| |
| import android.os.Process; |
| |
| import java.util.concurrent.CountDownLatch; |
| import java.util.concurrent.ExecutionException; |
| import java.util.concurrent.ExecutorService; |
| import java.util.concurrent.Executors; |
| import java.util.concurrent.Future; |
| import java.util.concurrent.ThreadFactory; |
| import java.util.concurrent.TimeUnit; |
| import java.util.concurrent.atomic.AtomicInteger; |
| |
| /** |
| * Utility methods for common functionality using java.util.concurrent package |
| * |
| * @hide |
| */ |
| public class ConcurrentUtils { |
| |
| private ConcurrentUtils() { |
| } |
| |
| /** |
| * Creates a thread pool using |
| * {@link java.util.concurrent.Executors#newFixedThreadPool(int, ThreadFactory)} |
| * |
| * @param nThreads the number of threads in the pool |
| * @param poolName base name of the threads in the pool |
| * @param linuxThreadPriority a Linux priority level. see {@link Process#setThreadPriority(int)} |
| * @return the newly created thread pool |
| */ |
| public static ExecutorService newFixedThreadPool(int nThreads, String poolName, |
| int linuxThreadPriority) { |
| return Executors.newFixedThreadPool(nThreads, |
| new ThreadFactory() { |
| private final AtomicInteger threadNum = new AtomicInteger(0); |
| |
| @Override |
| public Thread newThread(final Runnable r) { |
| return new Thread(poolName + threadNum.incrementAndGet()) { |
| @Override |
| public void run() { |
| Process.setThreadPriority(linuxThreadPriority); |
| r.run(); |
| } |
| }; |
| } |
| }); |
| } |
| |
| /** |
| * Waits if necessary for the computation to complete, and then retrieves its result. |
| * <p>If {@code InterruptedException} occurs, this method will interrupt the current thread |
| * and throw {@code IllegalStateException}</p> |
| * |
| * @param future future to wait for result |
| * @param description short description of the operation |
| * @return the computed result |
| * @throws IllegalStateException if interrupted during wait |
| * @throws RuntimeException if an error occurs while waiting for {@link Future#get()} |
| * @see Future#get() |
| */ |
| public static <T> T waitForFutureNoInterrupt(Future<T> future, String description) { |
| try { |
| return future.get(); |
| } catch (InterruptedException e) { |
| Thread.currentThread().interrupt(); |
| throw new IllegalStateException(description + " interrupted"); |
| } catch (ExecutionException e) { |
| throw new RuntimeException(description + " failed", e); |
| } |
| } |
| |
| /** |
| * Waits for {@link CountDownLatch#countDown()} to be called on the {@param countDownLatch}. |
| * <p>If {@link CountDownLatch#countDown()} doesn't occur within {@param timeoutMs}, this |
| * method will throw {@code IllegalStateException} |
| * <p>If {@code InterruptedException} occurs, this method will interrupt the current thread |
| * and throw {@code IllegalStateException} |
| * |
| * @param countDownLatch the CountDownLatch which {@link CountDownLatch#countDown()} is |
| * being waited on. |
| * @param timeoutMs the maximum time waited for {@link CountDownLatch#countDown()} |
| * @param description a short description of the operation |
| */ |
| public static void waitForCountDownNoInterrupt(CountDownLatch countDownLatch, long timeoutMs, |
| String description) { |
| try { |
| if (!countDownLatch.await(timeoutMs, TimeUnit.MILLISECONDS)) { |
| throw new IllegalStateException(description + " timed out."); |
| } |
| } catch (InterruptedException e) { |
| Thread.currentThread().interrupt(); |
| throw new IllegalStateException(description + " interrupted."); |
| } |
| } |
| } |