CODEWITHSUNDEEP
javanettyscheduler
forty-two
forty-two

Reputation: 12817

Why doesn't Netty execute my scheduled task?

Using Java 8 and Netty 4.1.1.Final, I would've expected the following test case to succeed, but it times out. What is it that I don't understand w.r.t. nettys event loop and scheduling of tasks?

public class SchedulerTest {


CountDownLatch latch;

TimerHandler handler;

static class TimerHandler extends ChannelInboundHandlerAdapter {

    ChannelHandlerContext ctx;

    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        super.channelActive(ctx);
        this.ctx = ctx;
    }

    private void timeout(final long ms) {
        ctx.executor().schedule(() -> {
            ctx.fireUserEventTriggered(ms);
        }, ms, TimeUnit.MILLISECONDS);
    }

}

static class TimeoutReactor extends ChannelInboundHandlerAdapter {
    CountDownLatch latch;

    public TimeoutReactor(CountDownLatch latch) {
        super();
        this.latch = latch;
    }

    @Override
    public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
        System.out.println("userEventTriggered");
        latch.countDown();
        super.userEventTriggered(ctx, evt);
    }

}

@Before
public void setUp() throws Exception {
    latch = new CountDownLatch(2);
    handler = new TimerHandler();
    TimeoutReactor reactor = new TimeoutReactor(latch);
    new EmbeddedChannel(handler, reactor);
}

@Test(timeout = 1000)
public void test() throws InterruptedException {

    handler.timeout(30);
    handler.timeout(20);
    latch.await();
}

}

Upvotes: 0

Views: 679

Answers (1)

Norman Maurer
Norman Maurer

Reputation: 23567

Its because EmbeddedChannel is no "real" Channel implementation and mainly use-able for testing and embedded ChannelHandlers. You will need to call "runPendingTasks()" after the given timeframe to have it run. If you use a "real" Channel implementation it will work without any extra method calls.

Upvotes: 5

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