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, 5 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
#	User	Rev	Content
1	dl	1.1	/*
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	dl	1.2	public class SystemTest extends JSR166TestCase {
11	dl	1.1	public static void main(String[] args) {
12	tim	1.4	junit.textui.TestRunner.run(suite());
13	dl	1.1	}
14
15			public static Test suite() {
16	tim	1.4	return new TestSuite(SystemTest.class);
17	dl	1.1	}
18
19	dl	1.2	/**
20	tim	1.4	* Nanos between readings of millis is no longer than millis (plus
21			* one milli to allow for rounding).
22	dl	1.2	* This shows only that nano timing not (much) worse than milli.
23			*/
24	dl	1.1	public void testNanoTime1() {
25	dl	1.2	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	tim	1.4	assertTrue(nanos < (millis+1) * 1000000);
38	dl	1.2	}
39			catch(InterruptedException ie) {
40	dl	1.3	unexpectedException();
41	dl	1.2	}
42	dl	1.1	}
43
44	dl	1.2	/**
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	dl	1.1	public void testNanoTime2() {
49	dl	1.2	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	dl	1.3	unexpectedException();
65	dl	1.2	}
66	dl	1.1	}
67
68			}
69