EpollTest Class — netty Architecture

Source Code

transport-native-epoll/src/test/java/io/netty/channel/epoll/EpollTest.java lines 30–99

public class EpollTest {

    @Test
    public void testIsAvailable() {
        assertTrue(Epoll.isAvailable());
    }

    @Test
    @Timeout(value = 5000, unit = TimeUnit.MILLISECONDS)
    public void testEpollWaitTimeoutAccuracy() throws Exception {
        final int timeoutMs = 200;
        final FileDescriptor epoll = Native.newEpollCreate();
        final EpollEventArray eventArray = new EpollEventArray(8);
        try {
            long startNs = System.nanoTime();
            // No fds registered, so this will just wait for the timeout.
            int ready = Native.epollWait(epoll, eventArray, timeoutMs);
            long elapsedMs = TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - startNs);

            assertEquals(0, ready);
            // Should have waited at least close to the timeout
            assertThat(elapsedMs).isGreaterThanOrEqualTo(timeoutMs - 20);
            // Should not have waited vastly longer than the timeout
            assertThat(elapsedMs).isLessThan(timeoutMs + 200);
        } finally {
            eventArray.free();
            epoll.close();
        }
    }

    // Testcase for https://github.com/netty/netty/issues/8444
    @Test
    @Timeout(value = 5000, unit = TimeUnit.MILLISECONDS)
    public void testEpollWaitWithTimeOutMinusOne() throws Exception  {
        final EpollEventArray eventArray = new EpollEventArray(8);
        try {
            final FileDescriptor epoll = Native.newEpollCreate();
            final FileDescriptor timerFd = Native.newTimerFd();
            final FileDescriptor eventfd = Native.newEventFd();
            Native.epollCtlAdd(epoll.intValue(), timerFd.intValue(), Native.EPOLLIN);
            Native.epollCtlAdd(epoll.intValue(), eventfd.intValue(), Native.EPOLLIN);

            final AtomicReference<Throwable> ref = new AtomicReference<Throwable>();
            Thread t = new Thread(new Runnable() {
                @Override
                public void run() {
                    try {
                        assertEquals(1, Native.epollWait(epoll, eventArray, false));
                        // This should have been woken up because of eventfd_write.
                        assertEquals(eventfd.intValue(), eventArray.fd(0));
                    } catch (Throwable cause) {
                        ref.set(cause);
                    }
                }
            });
            t.start();
            t.join(1000);
            assertTrue(t.isAlive());
            Native.eventFdWrite(eventfd.intValue(), 1);

            t.join();
            assertNull(ref.get());
            epoll.close();
            timerFd.close();
            eventfd.close();
        } finally {
            eventArray.free();
        }
    }
}