destroy() — netty Function Reference

Source Code

transport-classes-io_uring/src/main/java/io/netty/channel/uring/IoUringIoHandler.java lines 374–399

    @Override
    public void destroy() {
        SubmissionQueue submissionQueue = ringBuffer.ioUringSubmissionQueue();
        CompletionQueue completionQueue = ringBuffer.ioUringCompletionQueue();
        drainEventFd();
        if (submissionQueue.remaining() < 2) {
            // We need to submit 2 linked operations. Since they are linked, we cannot allow a submit-call to
            // separate them. We don't have enough room (< 2) in the queue, so we submit now to make more room.
            submissionQueue.submit();
        }
        // Try to drain all the IO from the queue first...
        long udata = UserData.encode(RINGFD_ID, Native.IORING_OP_NOP, (short) 0);
        // We need to also specify the Native.IOSQE_LINK flag for it to work as otherwise it is not correctly linked
        // with the timeout.
        // See:
        // - https://man7.org/linux/man-pages/man2/io_uring_enter.2.html
        // - https://git.kernel.dk/cgit/liburing/commit/?h=link-timeout&id=bc1bd5e97e2c758d6fd975bd35843b9b2c770c5a
        submissionQueue.addNop((byte) (Native.IOSQE_IO_DRAIN | Native.IOSQE_LINK), udata);
        // ... but only wait for 200 milliseconds on this
        submitAndWaitWithTimeout(submissionQueue, true, TimeUnit.MILLISECONDS.toNanos(200));
        completionQueue.process(this::handle);
        for (IoUringBufferRing ioUringBufferRing : registeredIoUringBufferRing.values()) {
            ioUringBufferRing.close();
        }
        completeRingClose();
    }