Examples with Phaser java8.util.concurrent.Phaser used on opensource projects

Example 1 with Phaser

use of java8.util.concurrent.Phaser in project streamsupport by stefan-zobel.

the class DoubleAccumulatorTest method testAccumulateAndGetMT.

/**
 * accumulates by multiple threads produce correct result
 */
public void testAccumulateAndGetMT() {
    final DoubleAccumulator acc = new DoubleAccumulator((x, y) -> x + y, 0.0);
    final int nThreads = ThreadLocalRandom.current().nextInt(1, 5);
    final Phaser phaser = new Phaser(nThreads + 1);
    final int incs = 1_000_000;
    // Gauss
    final double total = nThreads * incs / 2.0 * (incs - 1);
    final Runnable task = () -> {
        phaser.arriveAndAwaitAdvance();
        for (int i = 0; i < incs; i++) {
            acc.accumulate((double) i);
            assertTrue(acc.get() <= total);
        }
        phaser.arrive();
    };
    final ExecutorService p = Executors.newCachedThreadPool();
    PoolCleaner cleaner = null;
    try {
        cleaner = cleaner(p);
        for (int i = nThreads; i-- > 0; ) /**/
        p.execute(task);
        phaser.arriveAndAwaitAdvance();
        phaser.arriveAndAwaitAdvance();
        assertEquals(total, acc.get());
    } finally {
        if (cleaner != null) {
            cleaner.close();
        }
    }
}

Example 2 with Phaser

use of java8.util.concurrent.Phaser in project streamsupport by stefan-zobel.

the class PhaserTest method testArriveAndDeregister4.

/**
 * arriveAndDeregister deregisters one party from its parent when
 * the number of parties of child is zero after deregistration
 */
public void testArriveAndDeregister4() {
    Phaser parent = new Phaser();
    Phaser child = new Phaser(parent);
    assertEquals(0, parent.register());
    assertEquals(0, child.register());
    assertState(child, 0, 1, 1);
    assertState(parent, 0, 2, 2);
    assertEquals(0, child.arriveAndDeregister());
    assertState(child, 0, 0, 0);
    assertState(parent, 0, 1, 1);
}

Example 3 with Phaser

use of java8.util.concurrent.Phaser in project streamsupport by stefan-zobel.

the class PhaserTest method testPhaseIncrement1.

/**
 * the phase number increments correctly when tripping the barrier
 */
public void testPhaseIncrement1() {
    for (int size = 1; size < nine; size++) {
        final Phaser phaser = new Phaser(size);
        for (int index = 0; index <= (1 << size); index++) {
            int phase = phaser.arrive();
            assertTrue(index % size == 0 ? (index / size) == phase : index - (phase * size) > 0);
        }
    }
}

Example 4 with Phaser

use of java8.util.concurrent.Phaser in project streamsupport by stefan-zobel.

the class PhaserTest method testArrive3.

/**
 * arrive() returns a negative number if the Phaser is terminated
 */
public void testArrive3() {
    Phaser phaser = new Phaser(1);
    phaser.forceTermination();
    assertTerminated(phaser, 0, 1);
    assertEquals(0, phaser.getPhase() + Integer.MIN_VALUE);
    assertTrue(phaser.arrive() < 0);
    assertTrue(phaser.register() < 0);
    assertTrue(phaser.arriveAndDeregister() < 0);
    assertTrue(phaser.awaitAdvance(1) < 0);
    assertTrue(phaser.getPhase() < 0);
}

Example 5 with Phaser

use of java8.util.concurrent.Phaser in project streamsupport by stefan-zobel.

the class PhaserTest method testAwaitAdvance6.

/**
 * awaitAdvance returns when the phaser is externally terminated
 */
public void testAwaitAdvance6() {
    final Phaser phaser = new Phaser(3);
    final CountDownLatch pleaseForceTermination = new CountDownLatch(2);
    final List<Thread> threads = new ArrayList<>();
    for (int i = 0; i < 2; i++) {
        Runnable r = new CheckedRunnable() {

            public void realRun() {
                assertEquals(0, phaser.arrive());
                pleaseForceTermination.countDown();
                assertTrue(phaser.awaitAdvance(0) < 0);
                assertTrue(phaser.isTerminated());
                assertTrue(phaser.getPhase() < 0);
                assertEquals(0, phaser.getPhase() + Integer.MIN_VALUE);
                assertEquals(3, phaser.getRegisteredParties());
            }
        };
        threads.add(newStartedThread(r));
    }
    await(pleaseForceTermination);
    phaser.forceTermination();
    assertTrue(phaser.isTerminated());
    assertEquals(0, phaser.getPhase() + Integer.MIN_VALUE);
    for (Thread thread : threads) awaitTermination(thread);
    assertEquals(3, phaser.getRegisteredParties());
}