content: /*
   * Copyright 2014-2025 Real Logic Limited.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   * https://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package io.aeron.samples;
  
  import io.aeron.Aeron;
  import io.aeron.CommonContext;
  import io.aeron.ExclusivePublication;
  import io.aeron.Publication;
  import io.aeron.Subscription;
  import io.aeron.driver.MediaDriver;
  import io.aeron.driver.ThreadingMode;
  import io.aeron.logbuffer.BufferClaim;
  import org.agrona.concurrent.IdleStrategy;
  import org.agrona.concurrent.ShutdownSignalBarrier;
  
  import java.util.concurrent.atomic.AtomicBoolean;
  
  import static org.agrona.SystemUtil.loadPropertiesFiles;
  
  /**
   * Throughput test using {@link ExclusivePublication#tryClaim(int, BufferClaim)} over UDP transport.
   */
  public class EmbeddedBufferClaimIpcThroughput
  {
      private static final int BURST_LENGTH = 1_000_000;
      private static final int MESSAGE_LENGTH = SampleConfiguration.MESSAGE_LENGTH;
      private static final int FRAGMENT_COUNT_LIMIT = SampleConfiguration.FRAGMENT_COUNT_LIMIT;
      private static final String CHANNEL = CommonContext.IPC_CHANNEL;
      private static final int STREAM_ID = SampleConfiguration.STREAM_ID;
  
      /**
       * Main method for launching the process.
       *
       * @param args passed to the process.
       * @throws InterruptedException if the join on other threads is interrupted.
       */
      public static void main(final String[] args) throws InterruptedException
      {
          loadPropertiesFiles(args);
  
          final MediaDriver.Context ctx = new MediaDriver.Context()
              .threadingMode(ThreadingMode.SHARED);
  
          final AtomicBoolean running = new AtomicBoolean(true);
          try (ShutdownSignalBarrier barrier = new ShutdownSignalBarrier(() -> running.set(false));
              MediaDriver mediaDriver = MediaDriver.launch(ctx.terminationHook(barrier::signalAll));
              Aeron aeron = Aeron.connect(new Aeron.Context().aeronDirectoryName(mediaDriver.aeronDirectoryName()));
              Subscription subscription = aeron.addSubscription(CHANNEL, STREAM_ID);
              Publication publication = aeron.addPublication(CHANNEL, STREAM_ID))
          {
              final ImageRateSubscriber subscriber = new ImageRateSubscriber(FRAGMENT_COUNT_LIMIT, running, subscription);
              final Thread subscriberThread = new Thread(subscriber);
              subscriberThread.setName("subscriber");
              final Thread publisherThread = new Thread(new Publisher(running, publication));
              publisherThread.setName("publisher");
              final Thread rateReporterThread = new Thread(new ImageRateReporter(MESSAGE_LENGTH, running, subscriber));
              rateReporterThread.setName("rate-reporter");
  
              rateReporterThread.start();
              subscriberThread.start();
              publisherThread.start();
  
              barrier.await();
  
              subscriberThread.join();
              publisherThread.join();
              rateReporterThread.join();
          }
      }
  
      static final class Publisher implements Runnable
      {
          private final AtomicBoolean running;
          private final Publication publication;
  
          Publisher(final AtomicBoolean running, final Publication publication)
          {
              this.running = running;
              this.publication = publication;
          }
  
          public void run()
          {
              final IdleStrategy idleStrategy = SampleConfiguration.newIdleStrategy();
              final AtomicBoolean running = this.running;
              final Publication publication = this.publication;
              final BufferClaim bufferClaim = new BufferClaim();
              long backPressureCount = 0;
              long totalMessageCount = 0;
  
              outputResults:
              while (running.get())
              {
                  for (int i = 0; i < BURST_LENGTH; i++)
                  {
                      idleStrategy.reset();
                      while (publication.tryClaim(MESSAGE_LENGTH, bufferClaim) <= 0)
                      {
                          ++backPressureCount;
                          if (!running.get())
                          {
                              break outputResults;
                          }
                          idleStrategy.idle();
                      }
  
                      final int offset = bufferClaim.offset();
                      bufferClaim.buffer().putInt(offset, i); // Example field write
                      // Real app would write whatever fields are required via a flyweight like SBE
  
                      bufferClaim.commit();
  
                      ++totalMessageCount;
                  }
              }
  
              final double backPressureRatio = backPressureCount / (double)totalMessageCount;
              System.out.format("Publisher back pressure ratio: %f%n", backPressureRatio);
          }
      }
  }
  