1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
|
// Copyright 2014 Google Inc. 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();
}
}
}
|
