testScheduleTaskAtFixedRate() — netty Function Reference

Source Code

transport/src/test/java/io/netty/channel/SingleThreadEventLoopTest.java lines 187–223

    private static void testScheduleTaskAtFixedRate(EventLoop loopA) throws InterruptedException {
        final Queue<Long> timestamps = new LinkedBlockingQueue<Long>();
        final int expectedTimeStamps = 5;
        final CountDownLatch allTimeStampsLatch = new CountDownLatch(expectedTimeStamps);
        ScheduledFuture<?> f = loopA.scheduleAtFixedRate(new Runnable() {
            @Override
            public void run() {
                timestamps.add(System.nanoTime());
                try {
                    Thread.sleep(50);
                } catch (InterruptedException e) {
                    // Ignore
                }
                allTimeStampsLatch.countDown();
            }
        }, 100, 100, TimeUnit.MILLISECONDS);
        allTimeStampsLatch.await();
        assertTrue(f.cancel(true));
        Thread.sleep(300);
        assertEquals(expectedTimeStamps, timestamps.size());

        // Check if the task was run without a lag.
        Long firstTimestamp = null;
        int cnt = 0;
        for (Long t: timestamps) {
            if (firstTimestamp == null) {
                firstTimestamp = t;
                continue;
            }

            long timepoint = t - firstTimestamp;
            assertThat(timepoint).isGreaterThanOrEqualTo(TimeUnit.MILLISECONDS.toNanos(100 * cnt + 80));
            assertThat(timepoint).isLessThan(TimeUnit.MILLISECONDS.toNanos(100 * (cnt + 1) + 20));

            cnt ++;
        }
    }