test/tck/SystemTest.java

/*
 * Written by members of JCP JSR-166 Expert Group and released to the
 * public domain. Use, modify, and redistribute this code in any way
 * without acknowledgement. Other contributors include Andrew Wright,
 * Jeffrey Hayes, Pat Fischer, Mike Judd.
 */

import junit.framework.*;

public class SystemTest extends JSR166TestCase {
    public static void main(String[] args) {
        junit.textui.TestRunner.run(suite());   
    }
    
    public static Test suite() {
        return new TestSuite(SystemTest.class);
    }

    /**
     * Nanos between readings of millis is no longer than millis (plus
     * one milli to allow for rounding).
     * This shows only that nano timing not (much) worse than milli.
     */
    public void testNanoTime1() {
        try {
            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);
            assertTrue(nanos < (millis+1) * 1000000);
        }
        catch(InterruptedException ie) {
            unexpectedException();
        }
    }

    /**
     * Millis between readings of nanos is no longer than nanos
     * This shows only that nano timing not (much) worse than milli.
     */
    public void testNanoTime2() {
        try {
            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);
            assertTrue(millis * 1000000 <= nanos);
        }
        catch(InterruptedException ie) {
            unexpectedException();
        }
    }

}

Revision:	1.4
Committed:	Mon Dec 8 20:01:50 2003 UTC (20 years, 4 months ago) by tim
Branch:	MAIN
CVS Tags:	JSR166_DEC9_PRE_ES_SUBMIT, JSR166_DEC9_POST_ES_SUBMIT
Changes since 1.3:	+5 -4 lines
Log Message:	Allow extra millisecond to account for rounding in testNanoTime1
#	Content
1	/*
2	* Written by members of JCP JSR-166 Expert Group and released to the
3	* public domain. Use, modify, and redistribute this code in any way
4	* without acknowledgement. Other contributors include Andrew Wright,
5	* Jeffrey Hayes, Pat Fischer, Mike Judd.
6	*/
7
8	import junit.framework.*;
9
10	public class SystemTest extends JSR166TestCase {
11	public static void main(String[] args) {
12	junit.textui.TestRunner.run(suite());
13	}
14
15	public static Test suite() {
16	return new TestSuite(SystemTest.class);
17	}
18
19	/**
20	* Nanos between readings of millis is no longer than millis (plus
21	* one milli to allow for rounding).
22	* This shows only that nano timing not (much) worse than milli.
23	*/
24	public void testNanoTime1() {
25	try {
26	long m1 = System.currentTimeMillis();
27	Thread.sleep(1);
28	long n1 = System.nanoTime();
29	Thread.sleep(SHORT_DELAY_MS);
30	long n2 = System.nanoTime();
31	Thread.sleep(1);
32	long m2 = System.currentTimeMillis();
33	long millis = m2 - m1;
34	long nanos = n2 - n1;
35
36	assertTrue(nanos >= 0);
37	assertTrue(nanos < (millis+1) * 1000000);
38	}
39	catch(InterruptedException ie) {
40	unexpectedException();
41	}
42	}
43
44	/**
45	* Millis between readings of nanos is no longer than nanos
46	* This shows only that nano timing not (much) worse than milli.
47	*/
48	public void testNanoTime2() {
49	try {
50	long n1 = System.nanoTime();
51	Thread.sleep(1);
52	long m1 = System.currentTimeMillis();
53	Thread.sleep(SHORT_DELAY_MS);
54	long m2 = System.currentTimeMillis();
55	Thread.sleep(1);
56	long n2 = System.nanoTime();
57	long millis = m2 - m1;
58	long nanos = n2 - n1;
59
60	assertTrue(nanos >= 0);
61	assertTrue(millis * 1000000 <= nanos);
62	}
63	catch(InterruptedException ie) {
64	unexpectedException();
65	}
66	}
67
68	}
69