test/tck/CyclicBarrierTest.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 static java.util.concurrent.TimeUnit.MILLISECONDS;

import java.util.concurrent.BrokenBarrierException;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.CyclicBarrier;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadLocalRandom;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.atomic.AtomicInteger;

import junit.framework.Test;
import junit.framework.TestSuite;

public class CyclicBarrierTest extends JSR166TestCase {
    public static void main(String[] args) {
        main(suite(), args);
    }
    public static Test suite() {
        return new TestSuite(CyclicBarrierTest.class);
    }

    /**
     * Spin-waits till the number of waiters == numberOfWaiters.
     */
    void awaitNumberWaiting(CyclicBarrier barrier, int numberOfWaiters) {
        long startTime = System.nanoTime();
        while (barrier.getNumberWaiting() != numberOfWaiters) {
            if (millisElapsedSince(startTime) > LONG_DELAY_MS)
                fail("timed out");
            Thread.yield();
        }
    }

    /**
     * Creating with negative parties throws IllegalArgumentException
     */
    public void testConstructor1() {
        try {
            new CyclicBarrier(-1, (Runnable)null);
            shouldThrow();
        } catch (IllegalArgumentException success) {}
    }

    /**
     * Creating with negative parties and no action throws
     * IllegalArgumentException
     */
    public void testConstructor2() {
        try {
            new CyclicBarrier(-1);
            shouldThrow();
        } catch (IllegalArgumentException success) {}
    }

    /**
     * getParties returns the number of parties given in constructor
     */
    public void testGetParties() {
        CyclicBarrier b = new CyclicBarrier(2);
        assertEquals(2, b.getParties());
        assertEquals(0, b.getNumberWaiting());
    }

    /**
     * A 1-party barrier triggers after single await
     */
    public void testSingleParty() throws Exception {
        CyclicBarrier b = new CyclicBarrier(1);
        assertEquals(1, b.getParties());
        assertEquals(0, b.getNumberWaiting());
        b.await();
        b.await();
        assertEquals(0, b.getNumberWaiting());
    }

    /**
     * The supplied barrier action is run at barrier
     */
    public void testBarrierAction() throws Exception {
        final AtomicInteger count = new AtomicInteger(0);
        final Runnable incCount = new Runnable() { public void run() {
            count.getAndIncrement(); }};
        CyclicBarrier b = new CyclicBarrier(1, incCount);
        assertEquals(1, b.getParties());
        assertEquals(0, b.getNumberWaiting());
        b.await();
        b.await();
        assertEquals(0, b.getNumberWaiting());
        assertEquals(2, count.get());
    }

    /**
     * A 2-party/thread barrier triggers after both threads invoke await
     */
    public void testTwoParties() throws Exception {
        final CyclicBarrier b = new CyclicBarrier(2);
        Thread t = newStartedThread(new CheckedRunnable() {
            public void realRun() throws Exception {
                b.await();
                b.await();
                b.await();
                b.await();
            }});

        b.await();
        b.await();
        b.await();
        b.await();
        awaitTermination(t);
    }

    /**
     * An interruption in one party causes others waiting in await to
     * throw BrokenBarrierException
     */
    public void testAwait1_Interrupted_BrokenBarrier() {
        final CyclicBarrier c = new CyclicBarrier(3);
        final CountDownLatch pleaseInterrupt = new CountDownLatch(2);
        Thread t1 = new ThreadShouldThrow(InterruptedException.class) {
            public void realRun() throws Exception {
                pleaseInterrupt.countDown();
                c.await();
            }};
        Thread t2 = new ThreadShouldThrow(BrokenBarrierException.class) {
            public void realRun() throws Exception {
                pleaseInterrupt.countDown();
                c.await();
            }};

        t1.start();
        t2.start();
        await(pleaseInterrupt);
        t1.interrupt();
        awaitTermination(t1);
        awaitTermination(t2);
    }

    /**
     * An interruption in one party causes others waiting in timed await to
     * throw BrokenBarrierException
     */
    public void testAwait2_Interrupted_BrokenBarrier() throws Exception {
        final CyclicBarrier c = new CyclicBarrier(3);
        final CountDownLatch pleaseInterrupt = new CountDownLatch(2);
        Thread t1 = new ThreadShouldThrow(InterruptedException.class) {
            public void realRun() throws Exception {
                pleaseInterrupt.countDown();
                c.await(LONG_DELAY_MS, MILLISECONDS);
            }};
        Thread t2 = new ThreadShouldThrow(BrokenBarrierException.class) {
            public void realRun() throws Exception {
                pleaseInterrupt.countDown();
                c.await(LONG_DELAY_MS, MILLISECONDS);
            }};

        t1.start();
        t2.start();
        await(pleaseInterrupt);
        t1.interrupt();
        awaitTermination(t1);
        awaitTermination(t2);
    }

    /**
     * A timeout in timed await throws TimeoutException
     */
    public void testAwait3_TimeoutException() throws InterruptedException {
        final CyclicBarrier c = new CyclicBarrier(2);
        Thread t = newStartedThread(new CheckedRunnable() {
            public void realRun() throws Exception {
                long startTime = System.nanoTime();
                try {
                    c.await(timeoutMillis(), MILLISECONDS);
                    shouldThrow();
                } catch (TimeoutException success) {}
                assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
            }});

        awaitTermination(t);
    }

    /**
     * A timeout in one party causes others waiting in timed await to
     * throw BrokenBarrierException
     */
    public void testAwait4_Timeout_BrokenBarrier() throws InterruptedException {
        final CyclicBarrier c = new CyclicBarrier(3);
        Thread t1 = newStartedThread(new CheckedRunnable() {
            public void realRun() throws Exception {
                try {
                    c.await(LONG_DELAY_MS, MILLISECONDS);
                    shouldThrow();
                } catch (BrokenBarrierException success) {}
            }});
        Thread t2 = newStartedThread(new CheckedRunnable() {
            public void realRun() throws Exception {
                awaitNumberWaiting(c, 1);
                long startTime = System.nanoTime();
                try {
                    c.await(timeoutMillis(), MILLISECONDS);
                    shouldThrow();
                } catch (TimeoutException success) {}
                assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
            }});

        awaitTermination(t1);
        awaitTermination(t2);
    }

    /**
     * A timeout in one party causes others waiting in await to
     * throw BrokenBarrierException
     */
    public void testAwait5_Timeout_BrokenBarrier() throws InterruptedException {
        final CyclicBarrier c = new CyclicBarrier(3);
        Thread t1 = newStartedThread(new CheckedRunnable() {
            public void realRun() throws Exception {
                try {
                    c.await();
                    shouldThrow();
                } catch (BrokenBarrierException success) {}
            }});
        Thread t2 = newStartedThread(new CheckedRunnable() {
            public void realRun() throws Exception {
                awaitNumberWaiting(c, 1);
                long startTime = System.nanoTime();
                try {
                    c.await(timeoutMillis(), MILLISECONDS);
                    shouldThrow();
                } catch (TimeoutException success) {}
                assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
            }});

        awaitTermination(t1);
        awaitTermination(t2);
    }

    /**
     * A reset of an active barrier causes waiting threads to throw
     * BrokenBarrierException
     */
    public void testReset_BrokenBarrier() throws InterruptedException {
        final CyclicBarrier c = new CyclicBarrier(3);
        final CountDownLatch pleaseReset = new CountDownLatch(2);
        Thread t1 = new ThreadShouldThrow(BrokenBarrierException.class) {
            public void realRun() throws Exception {
                pleaseReset.countDown();
                c.await();
            }};
        Thread t2 = new ThreadShouldThrow(BrokenBarrierException.class) {
            public void realRun() throws Exception {
                pleaseReset.countDown();
                c.await();
            }};

        t1.start();
        t2.start();
        await(pleaseReset);

        awaitNumberWaiting(c, 2);
        c.reset();
        awaitTermination(t1);
        awaitTermination(t2);
    }

    /**
     * A reset before threads enter barrier does not throw
     * BrokenBarrierException
     */
    public void testReset_NoBrokenBarrier() throws Exception {
        final CyclicBarrier c = new CyclicBarrier(3);
        c.reset();

        Thread t1 = newStartedThread(new CheckedRunnable() {
            public void realRun() throws Exception {
                c.await();
            }});
        Thread t2 = newStartedThread(new CheckedRunnable() {
            public void realRun() throws Exception {
                c.await();
            }});

        c.await();
        awaitTermination(t1);
        awaitTermination(t2);
    }

    /**
     * Reset of a non-broken barrier does not break barrier
     */
    public void testResetWithoutBreakage() throws Exception {
        final CyclicBarrier barrier = new CyclicBarrier(3);
        for (int i = 0; i < 3; i++) {
            final CyclicBarrier start = new CyclicBarrier(3);
            Thread t1 = newStartedThread(new CheckedRunnable() {
                public void realRun() throws Exception {
                    start.await();
                    barrier.await();
                }});

            Thread t2 = newStartedThread(new CheckedRunnable() {
                public void realRun() throws Exception {
                    start.await();
                    barrier.await();
                }});

            start.await();
            barrier.await();
            awaitTermination(t1);
            awaitTermination(t2);
            assertFalse(barrier.isBroken());
            assertEquals(0, barrier.getNumberWaiting());
            if (i == 1) barrier.reset();
            assertFalse(barrier.isBroken());
            assertEquals(0, barrier.getNumberWaiting());
        }
    }

    /**
     * Reset of a barrier after interruption reinitializes it.
     */
    public void testResetAfterInterrupt() throws Exception {
        final CyclicBarrier barrier = new CyclicBarrier(3);
        for (int i = 0; i < 2; i++) {
            final CyclicBarrier start = new CyclicBarrier(3);
            Thread t1 = new ThreadShouldThrow(InterruptedException.class) {
                public void realRun() throws Exception {
                    start.await();
                    barrier.await();
                }};

            Thread t2 = new ThreadShouldThrow(BrokenBarrierException.class) {
                public void realRun() throws Exception {
                    start.await();
                    barrier.await();
                }};

            t1.start();
            t2.start();
            start.await();
            t1.interrupt();
            awaitTermination(t1);
            awaitTermination(t2);
            assertTrue(barrier.isBroken());
            assertEquals(0, barrier.getNumberWaiting());
            barrier.reset();
            assertFalse(barrier.isBroken());
            assertEquals(0, barrier.getNumberWaiting());
        }
    }

    /**
     * Reset of a barrier after timeout reinitializes it.
     */
    public void testResetAfterTimeout() throws Exception {
        final CyclicBarrier barrier = new CyclicBarrier(3);
        for (int i = 0; i < 2; i++) {
            assertEquals(0, barrier.getNumberWaiting());
            Thread t1 = newStartedThread(new CheckedRunnable() {
                public void realRun() throws Exception {
                    try {
                        barrier.await();
                        shouldThrow();
                    } catch (BrokenBarrierException success) {}
                }});
            Thread t2 = newStartedThread(new CheckedRunnable() {
                public void realRun() throws Exception {
                    awaitNumberWaiting(barrier, 1);
                    long startTime = System.nanoTime();
                    try {
                        barrier.await(timeoutMillis(), MILLISECONDS);
                        shouldThrow();
                    } catch (TimeoutException success) {}
                    assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
                }});

            awaitTermination(t1);
            awaitTermination(t2);
            assertEquals(0, barrier.getNumberWaiting());
            assertTrue(barrier.isBroken());
            assertEquals(0, barrier.getNumberWaiting());
            barrier.reset();
            assertFalse(barrier.isBroken());
            assertEquals(0, barrier.getNumberWaiting());
        }
    }

    /**
     * Reset of a barrier after a failed command reinitializes it.
     */
    public void testResetAfterCommandException() throws Exception {
        final CyclicBarrier barrier =
            new CyclicBarrier(3, new Runnable() {
                    public void run() {
                        throw new NullPointerException(); }});
        for (int i = 0; i < 2; i++) {
            final CyclicBarrier start = new CyclicBarrier(3);
            Thread t1 = new ThreadShouldThrow(BrokenBarrierException.class) {
                public void realRun() throws Exception {
                    start.await();
                    barrier.await();
                }};

            Thread t2 = new ThreadShouldThrow(BrokenBarrierException.class) {
                public void realRun() throws Exception {
                    start.await();
                    barrier.await();
                }};

            t1.start();
            t2.start();
            start.await();
            awaitNumberWaiting(barrier, 2);
            try {
                barrier.await();
                shouldThrow();
            } catch (NullPointerException success) {}
            awaitTermination(t1);
            awaitTermination(t2);
            assertTrue(barrier.isBroken());
            assertEquals(0, barrier.getNumberWaiting());
            barrier.reset();
            assertFalse(barrier.isBroken());
            assertEquals(0, barrier.getNumberWaiting());
        }
    }

    /**
     * There can be more threads calling await() than parties, as long as each
     * task only calls await once and the task count is a multiple of parties.
     */
    public void testMoreTasksThanParties() throws Exception {
        final ThreadLocalRandom rnd = ThreadLocalRandom.current();
        final int parties = rnd.nextInt(1, 5);
        final int nTasks = rnd.nextInt(1, 5) * parties;
        final AtomicInteger tripCount = new AtomicInteger(0);
        final AtomicInteger awaitCount = new AtomicInteger(0);
        final CyclicBarrier barrier =
            new CyclicBarrier(parties, () -> tripCount.getAndIncrement());
        final ExecutorService e = Executors.newFixedThreadPool(nTasks);
        final Runnable awaiter = () -> {
            try {
                if (randomBoolean())
                    barrier.await();
                else
                    barrier.await(LONG_DELAY_MS, MILLISECONDS);
                awaitCount.getAndIncrement();
            } catch (Throwable fail) { threadUnexpectedException(fail); }};
        try (PoolCleaner cleaner = cleaner(e)) {
            for (int i = nTasks; i--> 0; )
                e.execute(awaiter);
        }
        assertEquals(nTasks / parties, tripCount.get());
        assertEquals(nTasks, awaitCount.get());
        assertEquals(0, barrier.getNumberWaiting());
    }
}
Revision:	1.34
Committed:	Mon Sep 9 00:46:44 2019 UTC (4 years, 7 months ago) by jsr166
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.33:	+0 -1 lines
Log Message:	fix imports
#	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	1.17	* http://creativecommons.org/publicdomain/zero/1.0/
5	jsr166	1.9	* Other contributors include Andrew Wright, Jeffrey Hayes,
6			* Pat Fisher, Mike Judd.
7	dl	1.1	*/
8
9	jsr166	1.26	import static java.util.concurrent.TimeUnit.MILLISECONDS;
10
11	jsr166	1.24	import java.util.concurrent.BrokenBarrierException;
12			import java.util.concurrent.CountDownLatch;
13			import java.util.concurrent.CyclicBarrier;
14	jsr166	1.31	import java.util.concurrent.ExecutorService;
15			import java.util.concurrent.Executors;
16			import java.util.concurrent.ThreadLocalRandom;
17	jsr166	1.24	import java.util.concurrent.TimeoutException;
18	jsr166	1.28	import java.util.concurrent.atomic.AtomicInteger;
19	jsr166	1.26
20			import junit.framework.Test;
21			import junit.framework.TestSuite;
22	dl	1.1
23	jsr166	1.11	public class CyclicBarrierTest extends JSR166TestCase {
24	dl	1.1	public static void main(String[] args) {
25	jsr166	1.27	main(suite(), args);
26	dl	1.1	}
27			public static Test suite() {
28	jsr166	1.12	return new TestSuite(CyclicBarrierTest.class);
29	dl	1.1	}
30	dl	1.3
31			/**
32	jsr166	1.23	* Spin-waits till the number of waiters == numberOfWaiters.
33			*/
34			void awaitNumberWaiting(CyclicBarrier barrier, int numberOfWaiters) {
35			long startTime = System.nanoTime();
36			while (barrier.getNumberWaiting() != numberOfWaiters) {
37			if (millisElapsedSince(startTime) > LONG_DELAY_MS)
38			fail("timed out");
39			Thread.yield();
40			}
41			}
42
43			/**
44	jsr166	1.29	* Creating with negative parties throws IllegalArgumentException
45	dl	1.3	*/
46			public void testConstructor1() {
47			try {
48	dl	1.1	new CyclicBarrier(-1, (Runnable)null);
49	dl	1.3	shouldThrow();
50	jsr166	1.14	} catch (IllegalArgumentException success) {}
51	dl	1.1	}
52
53	dl	1.3	/**
54	jsr166	1.29	* Creating with negative parties and no action throws
55			* IllegalArgumentException
56	dl	1.3	*/
57			public void testConstructor2() {
58			try {
59	dl	1.1	new CyclicBarrier(-1);
60	dl	1.3	shouldThrow();
61	jsr166	1.14	} catch (IllegalArgumentException success) {}
62	dl	1.1	}
63
64	dl	1.3	/**
65	dl	1.4	* getParties returns the number of parties given in constructor
66	dl	1.3	*/
67	dl	1.4	public void testGetParties() {
68	dl	1.1	CyclicBarrier b = new CyclicBarrier(2);
69	jsr166	1.12	assertEquals(2, b.getParties());
70	dl	1.1	assertEquals(0, b.getNumberWaiting());
71			}
72
73	dl	1.3	/**
74	dl	1.5	* A 1-party barrier triggers after single await
75	dl	1.3	*/
76	jsr166	1.14	public void testSingleParty() throws Exception {
77			CyclicBarrier b = new CyclicBarrier(1);
78			assertEquals(1, b.getParties());
79			assertEquals(0, b.getNumberWaiting());
80			b.await();
81			b.await();
82			assertEquals(0, b.getNumberWaiting());
83	dl	1.1	}
84	jsr166	1.9
85	dl	1.3	/**
86	dl	1.4	* The supplied barrier action is run at barrier
87	dl	1.3	*/
88	jsr166	1.14	public void testBarrierAction() throws Exception {
89	jsr166	1.28	final AtomicInteger count = new AtomicInteger(0);
90			final Runnable incCount = new Runnable() { public void run() {
91			count.getAndIncrement(); }};
92			CyclicBarrier b = new CyclicBarrier(1, incCount);
93	jsr166	1.14	assertEquals(1, b.getParties());
94			assertEquals(0, b.getNumberWaiting());
95			b.await();
96			b.await();
97			assertEquals(0, b.getNumberWaiting());
98	jsr166	1.28	assertEquals(2, count.get());
99	dl	1.1	}
100
101	dl	1.3	/**
102	dl	1.5	* A 2-party/thread barrier triggers after both threads invoke await
103	dl	1.3	*/
104	jsr166	1.14	public void testTwoParties() throws Exception {
105	dl	1.1	final CyclicBarrier b = new CyclicBarrier(2);
106	jsr166	1.21	Thread t = newStartedThread(new CheckedRunnable() {
107	jsr166	1.14	public void realRun() throws Exception {
108			b.await();
109			b.await();
110			b.await();
111			b.await();
112			}});
113
114			b.await();
115			b.await();
116			b.await();
117			b.await();
118	jsr166	1.21	awaitTermination(t);
119	dl	1.1	}
120
121	dl	1.3	/**
122	dl	1.4	* An interruption in one party causes others waiting in await to
123			* throw BrokenBarrierException
124	dl	1.3	*/
125	jsr166	1.21	public void testAwait1_Interrupted_BrokenBarrier() {
126	dl	1.1	final CyclicBarrier c = new CyclicBarrier(3);
127	jsr166	1.21	final CountDownLatch pleaseInterrupt = new CountDownLatch(2);
128	jsr166	1.14	Thread t1 = new ThreadShouldThrow(InterruptedException.class) {
129			public void realRun() throws Exception {
130	jsr166	1.21	pleaseInterrupt.countDown();
131	jsr166	1.14	c.await();
132			}};
133			Thread t2 = new ThreadShouldThrow(BrokenBarrierException.class) {
134			public void realRun() throws Exception {
135	jsr166	1.21	pleaseInterrupt.countDown();
136	jsr166	1.14	c.await();
137			}};
138
139			t1.start();
140			t2.start();
141	jsr166	1.21	await(pleaseInterrupt);
142	jsr166	1.14	t1.interrupt();
143	jsr166	1.21	awaitTermination(t1);
144			awaitTermination(t2);
145	dl	1.1	}
146
147	dl	1.3	/**
148	dl	1.4	* An interruption in one party causes others waiting in timed await to
149			* throw BrokenBarrierException
150	dl	1.3	*/
151	jsr166	1.14	public void testAwait2_Interrupted_BrokenBarrier() throws Exception {
152	dl	1.8	final CyclicBarrier c = new CyclicBarrier(3);
153	jsr166	1.21	final CountDownLatch pleaseInterrupt = new CountDownLatch(2);
154	jsr166	1.14	Thread t1 = new ThreadShouldThrow(InterruptedException.class) {
155			public void realRun() throws Exception {
156	jsr166	1.21	pleaseInterrupt.countDown();
157	jsr166	1.14	c.await(LONG_DELAY_MS, MILLISECONDS);
158			}};
159			Thread t2 = new ThreadShouldThrow(BrokenBarrierException.class) {
160			public void realRun() throws Exception {
161	jsr166	1.21	pleaseInterrupt.countDown();
162	jsr166	1.14	c.await(LONG_DELAY_MS, MILLISECONDS);
163			}};
164
165			t1.start();
166			t2.start();
167	jsr166	1.21	await(pleaseInterrupt);
168	jsr166	1.14	t1.interrupt();
169	jsr166	1.21	awaitTermination(t1);
170			awaitTermination(t2);
171	dl	1.1	}
172	jsr166	1.9
173	dl	1.3	/**
174	dl	1.4	* A timeout in timed await throws TimeoutException
175	dl	1.3	*/
176	jsr166	1.19	public void testAwait3_TimeoutException() throws InterruptedException {
177	dl	1.1	final CyclicBarrier c = new CyclicBarrier(2);
178	jsr166	1.21	Thread t = newStartedThread(new CheckedRunnable() {
179	jsr166	1.14	public void realRun() throws Exception {
180	jsr166	1.21	long startTime = System.nanoTime();
181			try {
182			c.await(timeoutMillis(), MILLISECONDS);
183			shouldThrow();
184			} catch (TimeoutException success) {}
185			assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
186			}});
187	jsr166	1.9
188	jsr166	1.21	awaitTermination(t);
189	dl	1.5	}
190
191			/**
192			* A timeout in one party causes others waiting in timed await to
193			* throw BrokenBarrierException
194			*/
195	jsr166	1.14	public void testAwait4_Timeout_BrokenBarrier() throws InterruptedException {
196	dl	1.8	final CyclicBarrier c = new CyclicBarrier(3);
197	jsr166	1.21	Thread t1 = newStartedThread(new CheckedRunnable() {
198	jsr166	1.14	public void realRun() throws Exception {
199	jsr166	1.21	try {
200			c.await(LONG_DELAY_MS, MILLISECONDS);
201			shouldThrow();
202			} catch (BrokenBarrierException success) {}
203			}});
204			Thread t2 = newStartedThread(new CheckedRunnable() {
205	jsr166	1.14	public void realRun() throws Exception {
206	jsr166	1.23	awaitNumberWaiting(c, 1);
207	jsr166	1.21	long startTime = System.nanoTime();
208			try {
209			c.await(timeoutMillis(), MILLISECONDS);
210			shouldThrow();
211			} catch (TimeoutException success) {}
212			assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
213			}});
214	jsr166	1.14
215	jsr166	1.21	awaitTermination(t1);
216			awaitTermination(t2);
217	dl	1.5	}
218
219			/**
220			* A timeout in one party causes others waiting in await to
221			* throw BrokenBarrierException
222			*/
223	jsr166	1.14	public void testAwait5_Timeout_BrokenBarrier() throws InterruptedException {
224	dl	1.8	final CyclicBarrier c = new CyclicBarrier(3);
225	jsr166	1.21	Thread t1 = newStartedThread(new CheckedRunnable() {
226	jsr166	1.14	public void realRun() throws Exception {
227	jsr166	1.21	try {
228			c.await();
229			shouldThrow();
230			} catch (BrokenBarrierException success) {}
231			}});
232			Thread t2 = newStartedThread(new CheckedRunnable() {
233	jsr166	1.14	public void realRun() throws Exception {
234	jsr166	1.23	awaitNumberWaiting(c, 1);
235	jsr166	1.21	long startTime = System.nanoTime();
236			try {
237			c.await(timeoutMillis(), MILLISECONDS);
238			shouldThrow();
239			} catch (TimeoutException success) {}
240			assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
241			}});
242	jsr166	1.14
243	jsr166	1.21	awaitTermination(t1);
244			awaitTermination(t2);
245	dl	1.1	}
246	jsr166	1.9
247	dl	1.4	/**
248			* A reset of an active barrier causes waiting threads to throw
249			* BrokenBarrierException
250			*/
251	jsr166	1.14	public void testReset_BrokenBarrier() throws InterruptedException {
252	dl	1.4	final CyclicBarrier c = new CyclicBarrier(3);
253	jsr166	1.21	final CountDownLatch pleaseReset = new CountDownLatch(2);
254	jsr166	1.14	Thread t1 = new ThreadShouldThrow(BrokenBarrierException.class) {
255			public void realRun() throws Exception {
256	jsr166	1.21	pleaseReset.countDown();
257	jsr166	1.14	c.await();
258			}};
259			Thread t2 = new ThreadShouldThrow(BrokenBarrierException.class) {
260			public void realRun() throws Exception {
261	jsr166	1.21	pleaseReset.countDown();
262	jsr166	1.14	c.await();
263			}};
264
265			t1.start();
266			t2.start();
267	jsr166	1.21	await(pleaseReset);
268	jsr166	1.23
269			awaitNumberWaiting(c, 2);
270	jsr166	1.14	c.reset();
271	jsr166	1.21	awaitTermination(t1);
272			awaitTermination(t2);
273	dl	1.4	}
274
275			/**
276			* A reset before threads enter barrier does not throw
277			* BrokenBarrierException
278			*/
279	jsr166	1.14	public void testReset_NoBrokenBarrier() throws Exception {
280	dl	1.4	final CyclicBarrier c = new CyclicBarrier(3);
281	jsr166	1.21	c.reset();
282
283			Thread t1 = newStartedThread(new CheckedRunnable() {
284	jsr166	1.14	public void realRun() throws Exception {
285			c.await();
286			}});
287	jsr166	1.21	Thread t2 = newStartedThread(new CheckedRunnable() {
288	jsr166	1.14	public void realRun() throws Exception {
289			c.await();
290			}});
291
292			c.await();
293	jsr166	1.21	awaitTermination(t1);
294			awaitTermination(t2);
295	dl	1.4	}
296
297	dl	1.8	/**
298			* Reset of a non-broken barrier does not break barrier
299			*/
300	jsr166	1.14	public void testResetWithoutBreakage() throws Exception {
301			final CyclicBarrier barrier = new CyclicBarrier(3);
302			for (int i = 0; i < 3; i++) {
303	jsr166	1.21	final CyclicBarrier start = new CyclicBarrier(3);
304			Thread t1 = newStartedThread(new CheckedRunnable() {
305	jsr166	1.14	public void realRun() throws Exception {
306			start.await();
307			barrier.await();
308			}});
309
310	jsr166	1.21	Thread t2 = newStartedThread(new CheckedRunnable() {
311	jsr166	1.14	public void realRun() throws Exception {
312			start.await();
313			barrier.await();
314			}});
315
316			start.await();
317			barrier.await();
318	jsr166	1.21	awaitTermination(t1);
319			awaitTermination(t2);
320	jsr166	1.14	assertFalse(barrier.isBroken());
321			assertEquals(0, barrier.getNumberWaiting());
322			if (i == 1) barrier.reset();
323			assertFalse(barrier.isBroken());
324			assertEquals(0, barrier.getNumberWaiting());
325	dl	1.8	}
326			}
327	jsr166	1.9
328	dl	1.8	/**
329			* Reset of a barrier after interruption reinitializes it.
330			*/
331	jsr166	1.14	public void testResetAfterInterrupt() throws Exception {
332			final CyclicBarrier barrier = new CyclicBarrier(3);
333			for (int i = 0; i < 2; i++) {
334	jsr166	1.21	final CyclicBarrier start = new CyclicBarrier(3);
335	jsr166	1.14	Thread t1 = new ThreadShouldThrow(InterruptedException.class) {
336			public void realRun() throws Exception {
337			start.await();
338			barrier.await();
339			}};
340
341			Thread t2 = new ThreadShouldThrow(BrokenBarrierException.class) {
342			public void realRun() throws Exception {
343			start.await();
344			barrier.await();
345			}};
346
347			t1.start();
348			t2.start();
349			start.await();
350			t1.interrupt();
351	jsr166	1.21	awaitTermination(t1);
352			awaitTermination(t2);
353	jsr166	1.14	assertTrue(barrier.isBroken());
354			assertEquals(0, barrier.getNumberWaiting());
355			barrier.reset();
356			assertFalse(barrier.isBroken());
357			assertEquals(0, barrier.getNumberWaiting());
358	dl	1.8	}
359			}
360	jsr166	1.9
361	dl	1.8	/**
362			* Reset of a barrier after timeout reinitializes it.
363			*/
364	jsr166	1.14	public void testResetAfterTimeout() throws Exception {
365			final CyclicBarrier barrier = new CyclicBarrier(3);
366			for (int i = 0; i < 2; i++) {
367	jsr166	1.21	assertEquals(0, barrier.getNumberWaiting());
368			Thread t1 = newStartedThread(new CheckedRunnable() {
369			public void realRun() throws Exception {
370			try {
371			barrier.await();
372			shouldThrow();
373			} catch (BrokenBarrierException success) {}
374			}});
375			Thread t2 = newStartedThread(new CheckedRunnable() {
376	jsr166	1.14	public void realRun() throws Exception {
377	jsr166	1.23	awaitNumberWaiting(barrier, 1);
378	jsr166	1.21	long startTime = System.nanoTime();
379			try {
380			barrier.await(timeoutMillis(), MILLISECONDS);
381			shouldThrow();
382			} catch (TimeoutException success) {}
383			assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
384			}});
385	jsr166	1.14
386	jsr166	1.21	awaitTermination(t1);
387			awaitTermination(t2);
388			assertEquals(0, barrier.getNumberWaiting());
389	jsr166	1.14	assertTrue(barrier.isBroken());
390			assertEquals(0, barrier.getNumberWaiting());
391			barrier.reset();
392			assertFalse(barrier.isBroken());
393			assertEquals(0, barrier.getNumberWaiting());
394	dl	1.8	}
395			}
396
397			/**
398			* Reset of a barrier after a failed command reinitializes it.
399			*/
400	jsr166	1.14	public void testResetAfterCommandException() throws Exception {
401			final CyclicBarrier barrier =
402			new CyclicBarrier(3, new Runnable() {
403			public void run() {
404			throw new NullPointerException(); }});
405			for (int i = 0; i < 2; i++) {
406	jsr166	1.21	final CyclicBarrier start = new CyclicBarrier(3);
407	jsr166	1.14	Thread t1 = new ThreadShouldThrow(BrokenBarrierException.class) {
408			public void realRun() throws Exception {
409			start.await();
410			barrier.await();
411			}};
412
413			Thread t2 = new ThreadShouldThrow(BrokenBarrierException.class) {
414			public void realRun() throws Exception {
415			start.await();
416			barrier.await();
417			}};
418
419			t1.start();
420			t2.start();
421			start.await();
422	jsr166	1.23	awaitNumberWaiting(barrier, 2);
423	jsr166	1.14	try {
424			barrier.await();
425			shouldThrow();
426			} catch (NullPointerException success) {}
427	jsr166	1.21	awaitTermination(t1);
428			awaitTermination(t2);
429	jsr166	1.14	assertTrue(barrier.isBroken());
430			assertEquals(0, barrier.getNumberWaiting());
431			barrier.reset();
432			assertFalse(barrier.isBroken());
433			assertEquals(0, barrier.getNumberWaiting());
434	dl	1.8	}
435			}
436	jsr166	1.31
437			/**
438			* There can be more threads calling await() than parties, as long as each
439			* task only calls await once and the task count is a multiple of parties.
440			*/
441			public void testMoreTasksThanParties() throws Exception {
442			final ThreadLocalRandom rnd = ThreadLocalRandom.current();
443			final int parties = rnd.nextInt(1, 5);
444			final int nTasks = rnd.nextInt(1, 5) * parties;
445			final AtomicInteger tripCount = new AtomicInteger(0);
446			final AtomicInteger awaitCount = new AtomicInteger(0);
447			final CyclicBarrier barrier =
448			new CyclicBarrier(parties, () -> tripCount.getAndIncrement());
449			final ExecutorService e = Executors.newFixedThreadPool(nTasks);
450			final Runnable awaiter = () -> {
451			try {
452	jsr166	1.32	if (randomBoolean())
453	jsr166	1.31	barrier.await();
454			else
455			barrier.await(LONG_DELAY_MS, MILLISECONDS);
456			awaitCount.getAndIncrement();
457			} catch (Throwable fail) { threadUnexpectedException(fail); }};
458			try (PoolCleaner cleaner = cleaner(e)) {
459			for (int i = nTasks; i--> 0; )
460			e.execute(awaiter);
461			}
462			assertEquals(nTasks / parties, tripCount.get());
463			assertEquals(nTasks, awaitCount.get());
464			assertEquals(0, barrier.getNumberWaiting());
465			}
466	dl	1.1	}