Examples with IgniteClosure org.apache.ignite.lang.IgniteClosure used on opensource projects

Example 26 with IgniteClosure

use of org.apache.ignite.lang.IgniteClosure in project ignite by apache.

the class IgniteLockAbstractSelfTest method testFairness.

/**
 * Tests if lock is evenly acquired among nodes when fair flag is set on.
 * Since exact ordering of lock acquisitions cannot be guaranteed because it also depends
 * on the OS thread scheduling, certain deviation from uniform distribution is tolerated.
 * @throws Exception If failed.
 */
public void testFairness() throws Exception {
    if (gridCount() == 1)
        return;
    // Total number of ops.
    final long opsCount = 10000;
    // Allowed deviation from uniform distribution.
    final double tolerance = 0.05;
    // Shared counter.
    final String OPS_COUNTER = "ops_counter";
    // Number of threads, one per node.
    final int threadCount = gridCount();
    final AtomicLong threadCounter = new AtomicLong(0);
    Ignite ignite = startGrid(gridCount());
    // Initialize reentrant lock.
    IgniteLock l = ignite.reentrantLock("lock", true, true, true);
    // Initialize OPS_COUNTER.
    ignite.getOrCreateCache(OPS_COUNTER).put(OPS_COUNTER, (long) 0);
    final Map<Integer, Long> counts = new ConcurrentHashMap<>();
    IgniteInternalFuture<?> fut = multithreadedAsync(new Callable<Object>() {

        @Override
        public Object call() throws Exception {
            final int localNodeId = (int) threadCounter.getAndIncrement();
            final Ignite grid = grid(localNodeId);
            IgniteClosure<Ignite, Long> closure = new IgniteClosure<Ignite, Long>() {

                @Override
                public Long apply(Ignite ignite) {
                    IgniteLock l = ignite.reentrantLock("lock", true, true, true);
                    long localCount = 0;
                    IgniteCountDownLatch latch = ignite.countDownLatch("latch", threadCount, false, true);
                    latch.countDown();
                    latch.await();
                    while (true) {
                        l.lock();
                        try {
                            long opsCounter = (long) ignite.getOrCreateCache(OPS_COUNTER).get(OPS_COUNTER);
                            if (opsCounter == opsCount)
                                break;
                            ignite.getOrCreateCache(OPS_COUNTER).put(OPS_COUNTER, ++opsCounter);
                            localCount++;
                            if (localCount > 1000) {
                                assertTrue(localCount < (1 + tolerance) * opsCounter / threadCount);
                                assertTrue(localCount > (1 - tolerance) * opsCounter / threadCount);
                            }
                            if (localCount % 100 == 0) {
                                info("Node [id=" + ignite.cluster().localNode().id() + "] acquired " + localCount + " times. " + "Total ops count: " + opsCounter + "/" + opsCount + "]");
                            }
                        } finally {
                            l.unlock();
                        }
                    }
                    return localCount;
                }
            };
            long localCount = closure.apply(grid);
            counts.put(localNodeId, localCount);
            return null;
        }
    }, threadCount);
    fut.get();
    long totalSum = 0;
    for (int i = 0; i < gridCount(); i++) {
        totalSum += counts.get(i);
        info("Node " + grid(i).localNode().id() + " acquired the lock " + counts.get(i) + " times. ");
    }
    assertEquals(totalSum, opsCount);
    l.close();
    ignite.close();
}