Examples with Subscription io.aeron.Subscription used on opensource projects

Example 11 with Subscription

use of io.aeron.Subscription in project Aeron by real-logic.

the class SimpleSubscriber method main.

public static void main(final String[] args) throws Exception {
    // Maximum number of message fragments to receive during a single 'poll' operation
    final int fragmentLimitCount = 10;
    // The channel (an endpoint identifier) to receive messages from
    final String channel = "aeron:udp?endpoint=localhost:40123";
    // A unique identifier for a stream within a channel. Stream ID 0 is reserved
    // for internal use and should not be used by applications.
    final int streamId = 10;
    System.out.println("Subscribing to " + channel + " on stream Id " + streamId);
    final AtomicBoolean running = new AtomicBoolean(true);
    // Register a SIGINT handler for graceful shutdown.
    SigInt.register(() -> running.set(false));
    // dataHandler method is called for every new datagram received
    final FragmentHandler fragmentHandler = (buffer, offset, length, header) -> {
        final byte[] data = new byte[length];
        buffer.getBytes(offset, data);
        System.out.println(String.format("Received message (%s) to stream %d from session %x term id %x term offset %d (%d@%d)", new String(data), streamId, header.sessionId(), header.termId(), header.termOffset(), length, offset));
        // Received the intended message, time to exit the program
        running.set(false);
    };
    // Create a context, needed for client connection to media driver
    // A separate media driver process need to run prior to running this application
    final Aeron.Context ctx = new Aeron.Context();
    // clean up resources when this try block is finished.
    try (Aeron aeron = Aeron.connect(ctx);
        Subscription subscription = aeron.addSubscription(channel, streamId)) {
        final IdleStrategy idleStrategy = new BackoffIdleStrategy(100, 10, TimeUnit.MICROSECONDS.toNanos(1), TimeUnit.MICROSECONDS.toNanos(100));
        // Try to read the data from subscriber
        while (running.get()) {
            // poll delivers messages to the dataHandler as they arrive
            // and returns number of fragments read, or 0
            // if no data is available.
            final int fragmentsRead = subscription.poll(fragmentHandler, fragmentLimitCount);
            // Give the IdleStrategy a chance to spin/yield/sleep to reduce CPU
            // use if no messages were received.
            idleStrategy.idle(fragmentsRead);
        }
        System.out.println("Shutting down...");
    }
}

Example 12 with Subscription

use of io.aeron.Subscription in project Aeron by real-logic.

the class EmbeddedThroughput method main.

public static void main(final String[] args) throws Exception {
    MediaDriver.loadPropertiesFiles(args);
    final RateReporter reporter = new RateReporter(TimeUnit.SECONDS.toNanos(1), EmbeddedThroughput::printRate);
    final FragmentHandler rateReporterHandler = rateReporterHandler(reporter);
    final ExecutorService executor = Executors.newFixedThreadPool(2);
    final Aeron.Context context = new Aeron.Context();
    final AtomicBoolean running = new AtomicBoolean(true);
    try (MediaDriver ignore = MediaDriver.launch();
        Aeron aeron = Aeron.connect(context);
        Publication publication = aeron.addPublication(CHANNEL, STREAM_ID);
        Subscription subscription = aeron.addSubscription(CHANNEL, STREAM_ID)) {
        executor.execute(reporter);
        executor.execute(() -> SamplesUtil.subscriberLoop(rateReporterHandler, FRAGMENT_COUNT_LIMIT, running).accept(subscription));
        final ContinueBarrier barrier = new ContinueBarrier("Execute again?");
        do {
            System.out.format("%nStreaming %,d messages of size %d bytes to %s on stream Id %d%n", NUMBER_OF_MESSAGES, MESSAGE_LENGTH, CHANNEL, STREAM_ID);
            printingActive = true;
            long backPressureCount = 0;
            for (long i = 0; i < NUMBER_OF_MESSAGES; i++) {
                ATOMIC_BUFFER.putLong(0, i);
                OFFER_IDLE_STRATEGY.reset();
                while (publication.offer(ATOMIC_BUFFER, 0, ATOMIC_BUFFER.capacity()) < 0) {
                    OFFER_IDLE_STRATEGY.idle();
                    backPressureCount++;
                }
            }
            System.out.println("Done streaming. backPressureRatio=" + ((double) backPressureCount / NUMBER_OF_MESSAGES));
            if (0 < LINGER_TIMEOUT_MS) {
                System.out.println("Lingering for " + LINGER_TIMEOUT_MS + " milliseconds...");
                Thread.sleep(LINGER_TIMEOUT_MS);
            }
            printingActive = false;
        } while (barrier.await());
        running.set(false);
        reporter.halt();
        executor.shutdown();
    }
}