testSubmittingTaskWakesUpSuspendedExecutor() — netty Function Reference

Source Code

testsuite/src/main/java/io/netty/testsuite/transport/AbstractSingleThreadEventLoopTest.java lines 347–385

    @Test
    @Timeout(30)
    public void testSubmittingTaskWakesUpSuspendedExecutor() throws Exception {
        EventLoopGroup group = newAutoScalingEventLoopGroup();
        if (group == null) {
            return;
        }
        try {
            startAllExecutors(group);
            assertEquals(SCALING_MAX_THREADS, countActiveExecutors(group),
                         "Group should start with max threads.");

            long deadline = System.nanoTime() + TimeUnit.SECONDS.toNanos(10);
            while (countActiveExecutors(group) > SCALING_MIN_THREADS && System.nanoTime() < deadline) {
                Thread.sleep(100);
            }
            assertEquals(SCALING_MIN_THREADS, countActiveExecutors(group),
                         "Group did not scale down to min threads in time.");

            EventLoop suspendedLoop = null;
            for (EventExecutor exec : group) {
                if (exec.isSuspended()) {
                    suspendedLoop = (EventLoop) exec;
                    break;
                }
            }
            assertNotNull(suspendedLoop, "Could not find a suspended executor to test.");

            // Submit a task directly to the suspended loop, this should trigger the wake-up mechanism.
            Future<?> future = suspendedLoop.submit(() -> { });
            future.syncUninterruptibly();

            assertFalse(suspendedLoop.isSuspended(), "Executor should wake up after task submission.");
            assertEquals(SCALING_MAX_THREADS, countActiveExecutors(group),
                         "Active executor count should increase after wake-up.");
        } finally {
            group.shutdownGracefully().syncUninterruptibly();
        }
    }