test/tck/CountDownLatchTest.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/publicdomain/zero/1.0/
 * Other contributors include Andrew Wright, Jeffrey Hayes,
 * Pat Fisher, Mike Judd.
 */

import junit.framework.*;
import java.util.*;
import java.util.concurrent.*;
import static java.util.concurrent.TimeUnit.MILLISECONDS;

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

    /**
     * negative constructor argument throws IAE
     */
    public void testConstructor() {
        try {
            new CountDownLatch(-1);
            shouldThrow();
        } catch (IllegalArgumentException success) {}
    }

    /**
     * getCount returns initial count and decreases after countDown
     */
    public void testGetCount() {
        final CountDownLatch l = new CountDownLatch(2);
        assertEquals(2, l.getCount());
        l.countDown();
        assertEquals(1, l.getCount());
    }

    /**
     * countDown decrements count when positive and has no effect when zero
     */
    public void testCountDown() {
        final CountDownLatch l = new CountDownLatch(1);
        assertEquals(1, l.getCount());
        l.countDown();
        assertEquals(0, l.getCount());
        l.countDown();
        assertEquals(0, l.getCount());
    }

    /**
     * await returns after countDown to zero, but not before
     */
    public void testAwait() throws InterruptedException {
        final CountDownLatch l = new CountDownLatch(2);

        Thread t = new Thread(new CheckedRunnable() {
            public void realRun() throws InterruptedException {
                assertTrue(l.getCount() > 0);
                l.await();
                assertEquals(0, l.getCount());
            }});

        t.start();
        assertEquals(l.getCount(), 2);
        Thread.sleep(SHORT_DELAY_MS);
        l.countDown();
        assertEquals(l.getCount(), 1);
        l.countDown();
        assertEquals(l.getCount(), 0);
        t.join();
    }


    /**
     * timed await returns after countDown to zero
     */
    public void testTimedAwait() throws InterruptedException {
        final CountDownLatch l = new CountDownLatch(2);

        Thread t = new Thread(new CheckedRunnable() {
            public void realRun() throws InterruptedException {
                assertTrue(l.getCount() > 0);
                assertTrue(l.await(SMALL_DELAY_MS, MILLISECONDS));
            }});

        t.start();
        assertEquals(l.getCount(), 2);
        Thread.sleep(SHORT_DELAY_MS);
        l.countDown();
        assertEquals(l.getCount(), 1);
        l.countDown();
        assertEquals(l.getCount(), 0);
        t.join();
    }

    /**
     * await throws IE if interrupted before counted down
     */
    public void testAwait_InterruptedException() throws InterruptedException {
        final CountDownLatch l = new CountDownLatch(1);
        Thread t = new Thread(new CheckedInterruptedRunnable() {
            public void realRun() throws InterruptedException {
                assertTrue(l.getCount() > 0);
                l.await();
            }});

        t.start();
        assertEquals(l.getCount(), 1);
        t.interrupt();
        t.join();
    }

    /**
     * timed await throws IE if interrupted before counted down
     */
    public void testTimedAwait_InterruptedException() throws InterruptedException {
        final CountDownLatch l = new CountDownLatch(1);
        Thread t = new Thread(new CheckedInterruptedRunnable() {
            public void realRun() throws InterruptedException {
                assertTrue(l.getCount() > 0);
                l.await(MEDIUM_DELAY_MS, MILLISECONDS);
            }});

        t.start();
        Thread.sleep(SHORT_DELAY_MS);
        assertEquals(l.getCount(), 1);
        t.interrupt();
        t.join();
    }

    /**
     * timed await times out if not counted down before timeout
     */
    public void testAwaitTimeout() throws InterruptedException {
        final CountDownLatch l = new CountDownLatch(1);
        Thread t = new Thread(new CheckedRunnable() {
            public void realRun() throws InterruptedException {
                assertTrue(l.getCount() > 0);
                assertFalse(l.await(SHORT_DELAY_MS, MILLISECONDS));
                assertTrue(l.getCount() > 0);
            }});

        t.start();
        assertEquals(l.getCount(), 1);
        t.join();
    }

    /**
     * toString indicates current count
     */
    public void testToString() {
        CountDownLatch s = new CountDownLatch(2);
        String us = s.toString();
        assertTrue(us.indexOf("Count = 2") >= 0);
        s.countDown();
        String s1 = s.toString();
        assertTrue(s1.indexOf("Count = 1") >= 0);
        s.countDown();
        String s2 = s.toString();
        assertTrue(s2.indexOf("Count = 0") >= 0);
    }

}
Revision:	1.16
Committed:	Tue Mar 15 19:47:06 2011 UTC (13 years, 2 months ago) by jsr166
Branch:	MAIN
Changes since 1.15:	+1 -1 lines
Log Message:	Update Creative Commons license URL in legal notices
#	User	Rev	Content
1	dl	1.1	/*
2	dl	1.6	* 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	jsr166	1.16	* http://creativecommons.org/publicdomain/zero/1.0/
5	jsr166	1.8	* Other contributors include Andrew Wright, Jeffrey Hayes,
6			* Pat Fisher, Mike Judd.
7	dl	1.1	*/
8
9			import junit.framework.*;
10			import java.util.*;
11			import java.util.concurrent.*;
12	jsr166	1.12	import static java.util.concurrent.TimeUnit.MILLISECONDS;
13	dl	1.1
14	dl	1.2	public class CountDownLatchTest extends JSR166TestCase {
15	dl	1.1	public static void main(String[] args) {
16	jsr166	1.14	junit.textui.TestRunner.run(suite());
17	dl	1.1	}
18			public static Test suite() {
19	jsr166	1.11	return new TestSuite(CountDownLatchTest.class);
20	dl	1.1	}
21
22	dl	1.3	/**
23	dl	1.4	* negative constructor argument throws IAE
24	dl	1.3	*/
25			public void testConstructor() {
26	dl	1.2	try {
27			new CountDownLatch(-1);
28	dl	1.3	shouldThrow();
29	jsr166	1.10	} catch (IllegalArgumentException success) {}
30	dl	1.2	}
31	dl	1.1
32	dl	1.3	/**
33	dl	1.4	* getCount returns initial count and decreases after countDown
34	dl	1.3	*/
35			public void testGetCount() {
36	jsr166	1.11	final CountDownLatch l = new CountDownLatch(2);
37			assertEquals(2, l.getCount());
38			l.countDown();
39			assertEquals(1, l.getCount());
40	dl	1.1	}
41
42	dl	1.3	/**
43	dl	1.5	* countDown decrements count when positive and has no effect when zero
44	dl	1.4	*/
45	dl	1.5	public void testCountDown() {
46	jsr166	1.11	final CountDownLatch l = new CountDownLatch(1);
47			assertEquals(1, l.getCount());
48			l.countDown();
49			assertEquals(0, l.getCount());
50			l.countDown();
51			assertEquals(0, l.getCount());
52	dl	1.4	}
53
54			/**
55			* await returns after countDown to zero, but not before
56	dl	1.3	*/
57	jsr166	1.13	public void testAwait() throws InterruptedException {
58	jsr166	1.11	final CountDownLatch l = new CountDownLatch(2);
59	dl	1.1
60	jsr166	1.13	Thread t = new Thread(new CheckedRunnable() {
61			public void realRun() throws InterruptedException {
62	jsr166	1.15	assertTrue(l.getCount() > 0);
63	jsr166	1.13	l.await();
64	jsr166	1.15	assertEquals(0, l.getCount());
65	jsr166	1.13	}});
66
67	jsr166	1.11	t.start();
68	jsr166	1.13	assertEquals(l.getCount(), 2);
69			Thread.sleep(SHORT_DELAY_MS);
70			l.countDown();
71			assertEquals(l.getCount(), 1);
72			l.countDown();
73			assertEquals(l.getCount(), 0);
74			t.join();
75	dl	1.1	}
76	jsr166	1.8
77	dl	1.1
78	dl	1.3	/**
79	dl	1.4	* timed await returns after countDown to zero
80	dl	1.3	*/
81	jsr166	1.13	public void testTimedAwait() throws InterruptedException {
82	jsr166	1.11	final CountDownLatch l = new CountDownLatch(2);
83	dl	1.1
84	jsr166	1.13	Thread t = new Thread(new CheckedRunnable() {
85			public void realRun() throws InterruptedException {
86	jsr166	1.15	assertTrue(l.getCount() > 0);
87			assertTrue(l.await(SMALL_DELAY_MS, MILLISECONDS));
88	jsr166	1.13	}});
89
90	jsr166	1.11	t.start();
91	jsr166	1.13	assertEquals(l.getCount(), 2);
92			Thread.sleep(SHORT_DELAY_MS);
93			l.countDown();
94			assertEquals(l.getCount(), 1);
95			l.countDown();
96			assertEquals(l.getCount(), 0);
97			t.join();
98	dl	1.1	}
99	jsr166	1.8
100	dl	1.3	/**
101	dl	1.5	* await throws IE if interrupted before counted down
102	dl	1.3	*/
103	jsr166	1.13	public void testAwait_InterruptedException() throws InterruptedException {
104	dl	1.1	final CountDownLatch l = new CountDownLatch(1);
105	jsr166	1.13	Thread t = new Thread(new CheckedInterruptedRunnable() {
106			public void realRun() throws InterruptedException {
107	jsr166	1.15	assertTrue(l.getCount() > 0);
108	jsr166	1.13	l.await();
109			}});
110
111	jsr166	1.11	t.start();
112	jsr166	1.13	assertEquals(l.getCount(), 1);
113			t.interrupt();
114			t.join();
115	dl	1.1	}
116
117	dl	1.3	/**
118	dl	1.5	* timed await throws IE if interrupted before counted down
119	dl	1.3	*/
120	jsr166	1.13	public void testTimedAwait_InterruptedException() throws InterruptedException {
121	dl	1.1	final CountDownLatch l = new CountDownLatch(1);
122	jsr166	1.13	Thread t = new Thread(new CheckedInterruptedRunnable() {
123			public void realRun() throws InterruptedException {
124	jsr166	1.15	assertTrue(l.getCount() > 0);
125	jsr166	1.13	l.await(MEDIUM_DELAY_MS, MILLISECONDS);
126			}});
127
128	dl	1.1	t.start();
129	jsr166	1.13	Thread.sleep(SHORT_DELAY_MS);
130			assertEquals(l.getCount(), 1);
131			t.interrupt();
132			t.join();
133	dl	1.1	}
134
135	dl	1.3	/**
136	dl	1.4	* timed await times out if not counted down before timeout
137	dl	1.3	*/
138	jsr166	1.13	public void testAwaitTimeout() throws InterruptedException {
139	dl	1.1	final CountDownLatch l = new CountDownLatch(1);
140	jsr166	1.13	Thread t = new Thread(new CheckedRunnable() {
141			public void realRun() throws InterruptedException {
142	jsr166	1.15	assertTrue(l.getCount() > 0);
143			assertFalse(l.await(SHORT_DELAY_MS, MILLISECONDS));
144			assertTrue(l.getCount() > 0);
145	jsr166	1.13	}});
146
147	dl	1.1	t.start();
148	jsr166	1.13	assertEquals(l.getCount(), 1);
149			t.join();
150	dl	1.1	}
151
152	dl	1.7	/**
153			* toString indicates current count
154			*/
155			public void testToString() {
156			CountDownLatch s = new CountDownLatch(2);
157			String us = s.toString();
158			assertTrue(us.indexOf("Count = 2") >= 0);
159			s.countDown();
160			String s1 = s.toString();
161			assertTrue(s1.indexOf("Count = 1") >= 0);
162			s.countDown();
163			String s2 = s.toString();
164			assertTrue(s2.indexOf("Count = 0") >= 0);
165			}
166
167	dl	1.1	}