| // Copyright 2014 The Bazel Authors. All rights reserved. |
| // |
| // 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.google.devtools.build.lib.util.io; |
| |
| import com.google.common.io.ByteStreams; |
| |
| import org.junit.Test; |
| import org.junit.runner.RunWith; |
| import org.junit.runners.JUnit4; |
| |
| import java.io.OutputStream; |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.Random; |
| import java.util.concurrent.Callable; |
| import java.util.concurrent.ExecutionException; |
| import java.util.concurrent.ExecutorService; |
| import java.util.concurrent.Executors; |
| import java.util.concurrent.Future; |
| |
| /** |
| * Exercise {@link StreamMultiplexer} in a parallel setting and ensure there's |
| * no corruption. |
| */ |
| @RunWith(JUnit4.class) |
| public class StreamMultiplexerParallelStressTest { |
| |
| /** |
| * Characters that could likely cause corruption (they're used as control |
| * characters). |
| */ |
| char[] toughCharsToTry = {'\n', '@', '1', '2', '\0', '0'}; |
| |
| /** |
| * We use a demultiplexer as a simple sanity checker only - that is, we don't |
| * care what the demultiplexer writes, but we are taking advantage of its |
| * built in error checking. |
| */ |
| OutputStream devNull = ByteStreams.nullOutputStream(); |
| |
| StreamDemultiplexer demux = new StreamDemultiplexer((byte) 1, devNull, devNull, devNull); |
| |
| /** |
| * The multiplexer under test. |
| */ |
| StreamMultiplexer mux = new StreamMultiplexer(demux); |
| |
| /** |
| * Streams is the out / err / control output streams of the multiplexer which |
| * we will write to in parallel. |
| */ |
| OutputStream[] streams = { |
| mux.createStdout(), mux.createStderr(), mux.createControl()}; |
| |
| /** |
| * We will create a bunch of threads that write random data to the streams of |
| * the mux. |
| */ |
| class RandomDataPump implements Callable<Object> { |
| |
| private Random random; |
| |
| public RandomDataPump(int threadId) { |
| random = new Random(threadId * 0xdeadbeefL); |
| } |
| |
| @Override |
| public Object call() throws Exception { |
| Thread.yield(); |
| OutputStream out = streams[random.nextInt(2)]; |
| for (int i = 0; i < 10000; i++) { |
| switch (random.nextInt(5)) { |
| case 0: |
| out.write(random.nextInt()); |
| break; |
| case 1: |
| int index = random.nextInt(toughCharsToTry.length); |
| out.write(toughCharsToTry[index]); |
| break; |
| case 2: |
| byte[] buffer = new byte[random.nextInt(312)]; |
| random.nextBytes(buffer); |
| out.write(buffer); |
| break; |
| case 3: |
| out.flush(); |
| break; |
| case 4: |
| out = streams[random.nextInt(3)]; |
| break; |
| } |
| } |
| return null; |
| } |
| } |
| |
| @Test |
| public void testSingleThreadedStress() throws Exception { |
| new RandomDataPump(1).call(); |
| } |
| |
| @Test |
| public void testMultiThreadedStress() |
| throws InterruptedException, ExecutionException { |
| ExecutorService service = Executors.newFixedThreadPool(50); |
| |
| List<Future<?>> futures = new ArrayList<>(); |
| for (int threadId = 0; threadId < 50; threadId++) { |
| futures.add(service.submit(new RandomDataPump(threadId))); |
| } |
| for (Future<?> future : futures) { |
| future.get(); |
| } |
| } |
| |
| } |