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
|
/*
* 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/
* Other contributors include Andrew Wright, Jeffrey Hayes,
* Pat Fisher, Mike Judd.
*/
package test.java.util.concurrent.tck;
import junit.framework.Test;
import junit.framework.TestSuite;
public class SystemTest extends JSR166TestCase {
public static void main(String[] args) {
main(suite(), args);
}
public static Test suite() {
return new TestSuite(SystemTest.class);
}
/**
* Worst case rounding for millisecs; set for 60 cycle millis clock.
* This value might need to be changed on JVMs with coarser
* System.currentTimeMillis clocks.
*/
static final long MILLIS_ROUND = 17;
/**
* Nanos between readings of millis is no longer than millis (plus
* possible rounding).
* This shows only that nano timing not (much) worse than milli.
*/
public void testNanoTime1() throws InterruptedException {
long m1 = System.currentTimeMillis();
Thread.sleep(1);
long n1 = System.nanoTime();
Thread.sleep(SHORT_DELAY_MS);
long n2 = System.nanoTime();
Thread.sleep(1);
long m2 = System.currentTimeMillis();
long millis = m2 - m1;
long nanos = n2 - n1;
assertTrue(nanos >= 0);
long nanosAsMillis = nanos / 1000000;
assertTrue(nanosAsMillis <= millis + MILLIS_ROUND);
}
/**
* Millis between readings of nanos is less than nanos, adjusting
* for rounding.
* This shows only that nano timing not (much) worse than milli.
*/
public void testNanoTime2() throws InterruptedException {
long n1 = System.nanoTime();
Thread.sleep(1);
long m1 = System.currentTimeMillis();
Thread.sleep(SHORT_DELAY_MS);
long m2 = System.currentTimeMillis();
Thread.sleep(1);
long n2 = System.nanoTime();
long millis = m2 - m1;
long nanos = n2 - n1;
assertTrue(nanos >= 0);
long nanosAsMillis = nanos / 1000000;
assertTrue(millis <= nanosAsMillis + MILLIS_ROUND);
}
}
|
