author | ohair |
Tue, 25 May 2010 15:58:33 -0700 | |
changeset 5506 | 202f599c92aa |
parent 4347 | ab0a9f495844 |
child 7518 | 0282db800fe1 |
permissions | -rw-r--r-- |
2 | 1 |
/* |
2 |
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
|
3 |
* |
|
4 |
* This code is free software; you can redistribute it and/or modify it |
|
5 |
* under the terms of the GNU General Public License version 2 only, as |
|
6 |
* published by the Free Software Foundation. |
|
7 |
* |
|
8 |
* This code is distributed in the hope that it will be useful, but WITHOUT |
|
9 |
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
|
10 |
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
|
11 |
* version 2 for more details (a copy is included in the LICENSE file that |
|
12 |
* accompanied this code). |
|
13 |
* |
|
14 |
* You should have received a copy of the GNU General Public License version |
|
15 |
* 2 along with this work; if not, write to the Free Software Foundation, |
|
16 |
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
|
17 |
* |
|
5506 | 18 |
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
19 |
* or visit www.oracle.com if you need additional information or have any |
|
20 |
* questions. |
|
2 | 21 |
*/ |
22 |
||
23 |
/* |
|
24 |
* This file is available under and governed by the GNU General Public |
|
25 |
* License version 2 only, as published by the Free Software Foundation. |
|
26 |
* However, the following notice accompanied the original version of this |
|
27 |
* file: |
|
28 |
* |
|
29 |
* Written by Doug Lea with assistance from members of JCP JSR-166 |
|
30 |
* Expert Group and released to the public domain, as explained at |
|
31 |
* http://creativecommons.org/licenses/publicdomain |
|
32 |
*/ |
|
33 |
||
34 |
/* |
|
35 |
* @test |
|
36 |
* @bug 4486658 |
|
4347
ab0a9f495844
6907177: Update jdk tests to remove unncessary -source and -target options
darcy
parents:
2
diff
changeset
|
37 |
* @compile SimpleReentrantLockLoops.java |
2 | 38 |
* @run main/timeout=4500 SimpleReentrantLockLoops |
39 |
* @summary multiple threads using a single lock |
|
40 |
*/ |
|
41 |
||
42 |
import java.util.concurrent.*; |
|
43 |
import java.util.concurrent.locks.*; |
|
44 |
import java.util.*; |
|
45 |
||
46 |
public final class SimpleReentrantLockLoops { |
|
47 |
static final ExecutorService pool = Executors.newCachedThreadPool(); |
|
48 |
static final LoopHelpers.SimpleRandom rng = new LoopHelpers.SimpleRandom(); |
|
49 |
static boolean print = false; |
|
50 |
static int iters = 1000000; |
|
51 |
||
52 |
public static void main(String[] args) throws Exception { |
|
53 |
int maxThreads = 5; |
|
54 |
if (args.length > 0) |
|
55 |
maxThreads = Integer.parseInt(args[0]); |
|
56 |
||
57 |
print = true; |
|
58 |
||
59 |
int reps = 2; |
|
60 |
for (int i = 1; i <= maxThreads; i += (i+1) >>> 1) { |
|
61 |
int n = reps; |
|
62 |
if (reps > 1) --reps; |
|
63 |
while (n-- > 0) { |
|
64 |
System.out.print("Threads: " + i); |
|
65 |
new ReentrantLockLoop(i).test(); |
|
66 |
Thread.sleep(100); |
|
67 |
} |
|
68 |
} |
|
69 |
pool.shutdown(); |
|
70 |
if (! pool.awaitTermination(Long.MAX_VALUE, TimeUnit.NANOSECONDS)) |
|
71 |
throw new Error(); |
|
72 |
} |
|
73 |
||
74 |
static final class ReentrantLockLoop implements Runnable { |
|
75 |
private int v = rng.next(); |
|
76 |
private volatile int result = 17; |
|
77 |
private final ReentrantLock lock = new ReentrantLock(); |
|
78 |
private final LoopHelpers.BarrierTimer timer = new LoopHelpers.BarrierTimer(); |
|
79 |
private final CyclicBarrier barrier; |
|
80 |
private final int nthreads; |
|
81 |
ReentrantLockLoop(int nthreads) { |
|
82 |
this.nthreads = nthreads; |
|
83 |
barrier = new CyclicBarrier(nthreads+1, timer); |
|
84 |
} |
|
85 |
||
86 |
final void test() throws Exception { |
|
87 |
for (int i = 0; i < nthreads; ++i) |
|
88 |
pool.execute(this); |
|
89 |
barrier.await(); |
|
90 |
barrier.await(); |
|
91 |
if (print) { |
|
92 |
long time = timer.getTime(); |
|
93 |
long tpi = time / ((long)iters * nthreads); |
|
94 |
System.out.print("\t" + LoopHelpers.rightJustify(tpi) + " ns per lock"); |
|
95 |
double secs = (double)(time) / 1000000000.0; |
|
96 |
System.out.println("\t " + secs + "s run time"); |
|
97 |
} |
|
98 |
||
99 |
int r = result; |
|
100 |
if (r == 0) // avoid overoptimization |
|
101 |
System.out.println("useless result: " + r); |
|
102 |
} |
|
103 |
||
104 |
public final void run() { |
|
105 |
try { |
|
106 |
barrier.await(); |
|
107 |
int sum = v; |
|
108 |
int x = 0; |
|
109 |
int n = iters; |
|
110 |
do { |
|
111 |
lock.lock(); |
|
112 |
try { |
|
113 |
if ((n & 255) == 0) |
|
114 |
v = x = LoopHelpers.compute2(LoopHelpers.compute1(v)); |
|
115 |
else |
|
116 |
v = x += ~(v - n); |
|
117 |
} |
|
118 |
finally { |
|
119 |
lock.unlock(); |
|
120 |
} |
|
121 |
// Once in a while, do something more expensive |
|
122 |
if ((~n & 255) == 0) { |
|
123 |
sum += LoopHelpers.compute1(LoopHelpers.compute2(x)); |
|
124 |
} |
|
125 |
else |
|
126 |
sum += sum ^ x; |
|
127 |
} while (n-- > 0); |
|
128 |
barrier.await(); |
|
129 |
result += sum; |
|
130 |
} |
|
131 |
catch (Exception ie) { |
|
132 |
return; |
|
133 |
} |
|
134 |
} |
|
135 |
} |
|
136 |
||
137 |
} |