1 |
dl |
1.1 |
/* |
2 |
dl |
1.5 |
* Written by Doug Lea with assistance from members of JCP JSR-166 |
3 |
|
|
* Expert Group and released to the public domain, as explained at |
4 |
jsr166 |
1.11 |
* http://creativecommons.org/publicdomain/zero/1.0/ |
5 |
jsr166 |
1.7 |
* Other contributors include Andrew Wright, Jeffrey Hayes, |
6 |
|
|
* Pat Fisher, Mike Judd. |
7 |
dl |
1.1 |
*/ |
8 |
|
|
|
9 |
jsr166 |
1.12 |
import junit.framework.Test; |
10 |
|
|
import junit.framework.TestSuite; |
11 |
dl |
1.1 |
|
12 |
dl |
1.2 |
public class SystemTest extends JSR166TestCase { |
13 |
dl |
1.1 |
public static void main(String[] args) { |
14 |
jsr166 |
1.13 |
main(suite(), args); |
15 |
dl |
1.1 |
} |
16 |
jsr166 |
1.7 |
|
17 |
dl |
1.1 |
public static Test suite() { |
18 |
tim |
1.4 |
return new TestSuite(SystemTest.class); |
19 |
dl |
1.1 |
} |
20 |
|
|
|
21 |
jsr166 |
1.7 |
/** |
22 |
dl |
1.6 |
* Worst case rounding for millisecs; set for 60 cycle millis clock. |
23 |
jsr166 |
1.9 |
* This value might need to be changed on JVMs with coarser |
24 |
jsr166 |
1.10 |
* System.currentTimeMillis clocks. |
25 |
dl |
1.6 |
*/ |
26 |
|
|
static final long MILLIS_ROUND = 17; |
27 |
|
|
|
28 |
dl |
1.2 |
/** |
29 |
tim |
1.4 |
* Nanos between readings of millis is no longer than millis (plus |
30 |
jsr166 |
1.14 |
* possible rounding), and vice versa. |
31 |
dl |
1.2 |
* This shows only that nano timing not (much) worse than milli. |
32 |
|
|
*/ |
33 |
jsr166 |
1.14 |
public void testNanoTime() throws InterruptedException { |
34 |
|
|
long m0 = System.currentTimeMillis(); |
35 |
|
|
long n0 = System.nanoTime(); |
36 |
|
|
Thread.sleep(1); |
37 |
jsr166 |
1.9 |
long m1 = System.currentTimeMillis(); |
38 |
|
|
long n1 = System.nanoTime(); |
39 |
jsr166 |
1.14 |
Thread.sleep(50); // avoid possibly scaled SHORT_DELAY_MS |
40 |
|
|
long m2 = System.currentTimeMillis(); |
41 |
jsr166 |
1.9 |
long n2 = System.nanoTime(); |
42 |
|
|
Thread.sleep(1); |
43 |
jsr166 |
1.14 |
long m3 = System.currentTimeMillis(); |
44 |
|
|
long n3 = System.nanoTime(); |
45 |
|
|
assertTrue((n2 - n1) / 1_000_000 <= m3 - m0 + MILLIS_ROUND); |
46 |
|
|
assertTrue(m2 - m1 <= (n3 - n0) / 1_000_000 + MILLIS_ROUND); |
47 |
dl |
1.1 |
} |
48 |
|
|
} |