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Comparing jsr166/src/test/tck/SystemTest.java (file contents):
Revision 1.2 by dl, Sun Sep 14 20:42:41 2003 UTC vs.
Revision 1.14 by jsr166, Sun May 14 03:09:25 2017 UTC

# Line 1 | Line 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.
2 > * 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/publicdomain/zero/1.0/
5 > * Other contributors include Andrew Wright, Jeffrey Hayes,
6 > * Pat Fisher, Mike Judd.
7   */
8  
9 < import junit.framework.*;
9 > import junit.framework.Test;
10 > import junit.framework.TestSuite;
11  
12   public class SystemTest extends JSR166TestCase {
13      public static void main(String[] args) {
14 <        junit.textui.TestRunner.run(suite());  
14 >        main(suite(), args);
15      }
16 <    
16 >
17      public static Test suite() {
18 <        return new TestSuite(SystemTest.class);
18 >        return new TestSuite(SystemTest.class);
19      }
20  
21      /**
22 <     * Nanos between readings of millis is no longer than millis.
23 <     * This shows only that nano timing not (much) worse than milli.
22 >     * Worst case rounding for millisecs; set for 60 cycle millis clock.
23 >     * This value might need to be changed on JVMs with coarser
24 >     * System.currentTimeMillis clocks.
25       */
26 <    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 <            fail("unexpected exception");
40 <        }
41 <    }
26 >    static final long MILLIS_ROUND = 17;
27  
28      /**
29 <     * Millis between readings of nanos is no longer than nanos
29 >     * Nanos between readings of millis is no longer than millis (plus
30 >     * possible rounding), and vice versa.
31       * This shows only that nano timing not (much) worse than milli.
32       */
33 <    public void testNanoTime2() {
34 <        try {
35 <            long n1 = System.nanoTime();
36 <            Thread.sleep(1);
37 <            long m1 = System.currentTimeMillis();
38 <            Thread.sleep(SHORT_DELAY_MS);
39 <            long m2 = System.currentTimeMillis();
40 <            Thread.sleep(1);
41 <            long n2 = System.nanoTime();
42 <            long millis = m2 - m1;
43 <            long nanos = n2 - n1;
44 <            
45 <            assertTrue(nanos >= 0);
46 <            assertTrue(millis * 1000000 <= nanos);
61 <        }
62 <        catch(InterruptedException ie) {
63 <            fail("unexpected exception");
64 <        }
33 >    public void testNanoTime() throws InterruptedException {
34 >        long m0 = System.currentTimeMillis();
35 >        long n0 = System.nanoTime();
36 >        Thread.sleep(1);
37 >        long m1 = System.currentTimeMillis();
38 >        long n1 = System.nanoTime();
39 >        Thread.sleep(50);       // avoid possibly scaled SHORT_DELAY_MS
40 >        long m2 = System.currentTimeMillis();
41 >        long n2 = System.nanoTime();
42 >        Thread.sleep(1);
43 >        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      }
66
48   }
68

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