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.
     * 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 * 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:	1.3
Committed:	Sat Sep 20 18:20:08 2003 UTC (20 years, 7 months ago) by dl
Branch:	MAIN
CVS Tags:	JSR166_NOV3_FREEZE
Changes since 1.2:	+2 -2 lines
Log Message:	Documentation scaffolding
#	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.
21	* This shows only that nano timing not (much) worse than milli.
22	*/
23	public void testNanoTime1() {
24	try {
25	long m1 = System.currentTimeMillis();
26	Thread.sleep(1);
27	long n1 = System.nanoTime();
28	Thread.sleep(SHORT_DELAY_MS);
29	long n2 = System.nanoTime();
30	Thread.sleep(1);
31	long m2 = System.currentTimeMillis();
32	long millis = m2 - m1;
33	long nanos = n2 - n1;
34
35	assertTrue(nanos >= 0);
36	assertTrue(nanos <= millis * 1000000);
37	}
38	catch(InterruptedException ie) {
39	unexpectedException();
40	}
41	}
42
43	/**
44	* Millis between readings of nanos is no longer than nanos
45	* This shows only that nano timing not (much) worse than milli.
46	*/
47	public void testNanoTime2() {
48	try {
49	long n1 = System.nanoTime();
50	Thread.sleep(1);
51	long m1 = System.currentTimeMillis();
52	Thread.sleep(SHORT_DELAY_MS);
53	long m2 = System.currentTimeMillis();
54	Thread.sleep(1);
55	long n2 = System.nanoTime();
56	long millis = m2 - m1;
57	long nanos = n2 - n1;
58
59	assertTrue(nanos >= 0);
60	assertTrue(millis * 1000000 <= nanos);
61	}
62	catch(InterruptedException ie) {
63	unexpectedException();
64	}
65	}
66
67	}
68