test/tck/SystemTest.java

/*
 * 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/licenses/publicdomain
 * Other contributors include Andrew Wright, Jeffrey Hayes, 
 * Pat Fisher, 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:	1.5
Committed:	Sat Dec 27 19:26:44 2003 UTC (20 years, 4 months ago) by dl
Branch:	MAIN
Changes since 1.4:	+5 -4 lines
Log Message:	Headers reference Creative Commons
#	User	Rev	Content
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			* http://creativecommons.org/licenses/publicdomain
5			* Other contributors include Andrew Wright, Jeffrey Hayes,
6			* Pat Fisher, Mike Judd.
7	dl	1.1	*/
8
9			import junit.framework.*;
10
11	dl	1.2	public class SystemTest extends JSR166TestCase {
12	dl	1.1	public static void main(String[] args) {
13	tim	1.4	junit.textui.TestRunner.run(suite());
14	dl	1.1	}
15
16			public static Test suite() {
17	tim	1.4	return new TestSuite(SystemTest.class);
18	dl	1.1	}
19
20	dl	1.2	/**
21	tim	1.4	* Nanos between readings of millis is no longer than millis (plus
22			* one milli to allow for rounding).
23	dl	1.2	* This shows only that nano timing not (much) worse than milli.
24			*/
25	dl	1.1	public void testNanoTime1() {
26	dl	1.2	try {
27			long m1 = System.currentTimeMillis();
28			Thread.sleep(1);
29			long n1 = System.nanoTime();
30			Thread.sleep(SHORT_DELAY_MS);
31			long n2 = System.nanoTime();
32			Thread.sleep(1);
33			long m2 = System.currentTimeMillis();
34			long millis = m2 - m1;
35			long nanos = n2 - n1;
36
37			assertTrue(nanos >= 0);
38	tim	1.4	assertTrue(nanos < (millis+1) * 1000000);
39	dl	1.2	}
40			catch(InterruptedException ie) {
41	dl	1.3	unexpectedException();
42	dl	1.2	}
43	dl	1.1	}
44
45	dl	1.2	/**
46			* Millis between readings of nanos is no longer than nanos
47			* This shows only that nano timing not (much) worse than milli.
48			*/
49	dl	1.1	public void testNanoTime2() {
50	dl	1.2	try {
51			long n1 = System.nanoTime();
52			Thread.sleep(1);
53			long m1 = System.currentTimeMillis();
54			Thread.sleep(SHORT_DELAY_MS);
55			long m2 = System.currentTimeMillis();
56			Thread.sleep(1);
57			long n2 = System.nanoTime();
58			long millis = m2 - m1;
59			long nanos = n2 - n1;
60
61			assertTrue(nanos >= 0);
62			assertTrue(millis * 1000000 <= nanos);
63			}
64			catch(InterruptedException ie) {
65	dl	1.3	unexpectedException();
66	dl	1.2	}
67	dl	1.1	}
68
69			}
70