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
129
130
131
132
133
134
135
|
/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/*
* This file is available under and governed by the GNU General Public
* License version 2 only, as published by the Free Software Foundation.
* However, the following notice accompanied the original version of this
* file:
*
* Written by Doug Lea with assistance from members of JCP JSR-166
* Expert Group and released to the public domain, as explained at
* http://creativecommons.org/publicdomain/zero/1.0/
*/
/*
* @test
* @bug 4486658
* @summary Checks for missed signals by locking and unlocking each of an array of locks once per thread
* @library /lib/testlibrary/
*/
import static java.util.concurrent.TimeUnit.MILLISECONDS;
import java.util.concurrent.CyclicBarrier;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadLocalRandom;
import java.util.concurrent.locks.ReentrantLock;
import jdk.testlibrary.Utils;
public final class LockOncePerThreadLoops {
static final long LONG_DELAY_MS = Utils.adjustTimeout(10_000);
static final ExecutorService pool = Executors.newCachedThreadPool();
static boolean print = false;
static int nlocks = 20_000;
static int nthreads = 20;
static int replications = 3;
public static void main(String[] args) throws Exception {
if (args.length > 0)
replications = Integer.parseInt(args[0]);
if (args.length > 1)
nlocks = Integer.parseInt(args[1]);
print = true;
for (int i = 0; i < replications; ++i) {
System.out.print("Iteration: " + i);
new ReentrantLockLoop().test();
}
pool.shutdown();
if (! pool.awaitTermination(LONG_DELAY_MS, MILLISECONDS))
throw new Error();
}
static final class ReentrantLockLoop implements Runnable {
private int v = ThreadLocalRandom.current().nextInt();
private volatile int result = 17;
final ReentrantLock[]locks = new ReentrantLock[nlocks];
private final ReentrantLock lock = new ReentrantLock();
private final LoopHelpers.BarrierTimer timer = new LoopHelpers.BarrierTimer();
private final CyclicBarrier barrier;
ReentrantLockLoop() {
barrier = new CyclicBarrier(nthreads+1, timer);
for (int i = 0; i < nlocks; ++i)
locks[i] = new ReentrantLock();
}
final void test() throws Exception {
for (int i = 0; i < nthreads; ++i)
pool.execute(this);
barrier.await();
barrier.await();
if (print) {
long time = timer.getTime();
double secs = (double)(time) / 1000000000.0;
System.out.println("\t " + secs + "s run time");
}
int r = result;
if (r == 0) // avoid overoptimization
System.out.println("useless result: " + r);
}
public final void run() {
try {
barrier.await();
int sum = v;
int x = 0;
for (int i = 0; i < locks.length; ++i) {
locks[i].lock();
try {
v = x += ~(v - i);
}
finally {
locks[i].unlock();
}
// Once in a while, do something more expensive
if ((~i & 255) == 0) {
sum += LoopHelpers.compute1(LoopHelpers.compute2(x));
}
else
sum += sum ^ x;
}
barrier.await();
result += sum;
}
catch (Exception ex) {
return;
}
}
}
}
|
