While waiting and talking to your crush, from time to time, you check the number displayed on the counter to see if it's your turn already.

Then at some point, it finally is your turn. You go to the counter, get your burgers and come back to the table.

<img src="/img/async/concurrent-burgers/concurrent-burgers-06.png" class="illustration">

@Singleton
public class DefaultPluginDependenciesResolver implements PluginDependenciesResolver {
    private static final String REPOSITORY_CONTEXT = org.apache.maven.api.services.RequestTrace.CONTEXT_PLUGIN;

    private final Logger logger = LoggerFactory.getLogger(getClass());

    private final RepositorySystem repoSystem;

    private final List<MavenPluginDependenciesValidator> dependenciesValidators;

    @Inject

 *   <li><b>Convenience methods:</b> These are implementations of common operations that are
 *       typically implemented by opening a writer using one of the methods in the first category,
 *       doing something and finally closing the writer that was opened.
 * </ul>
 *
 * <p>Any {@link ByteSink} may be viewed as a {@code CharSink} with a specific {@linkplain Charset

    try {
      b0 = source.readByte() and 0xff
    } finally {
      source.timeout().timeout(timeoutBefore, TimeUnit.NANOSECONDS)
    }

    opcode = b0 and B0_MASK_OPCODE
    isFinalFrame = b0 and B0_FLAG_FIN != 0
    isControlFrame = b0 and OPCODE_FLAG_CONTROL != 0

    // Control frames must be final frames (cannot contain continuations).
    if (isControlFrame && !isFinalFrame) {

 * @since 26.0
 */
@J2ktIncompatible
@GwtIncompatible
public final class ExecutionSequencer {

  private ExecutionSequencer() {}

  /** Creates a new instance. */
  public static ExecutionSequencer create() {
    return new ExecutionSequencer();
  }

  /** This reference acts as a pointer tracking the head of a linked list of ListenableFutures. */
  private final AtomicReference<ListenableFuture<@Nullable Void>> ref =

/**
 * DefaultBuildPluginManager
 */
@Named
@Singleton
public class DefaultBuildPluginManager implements BuildPluginManager {

    private final MavenPluginManager mavenPluginManager;
    private final LegacySupport legacySupport;
    private final MojoExecutionScope scope;
    private final MojoExecutionListener mojoExecutionListener;

    @Inject
    public DefaultBuildPluginManager(
            MavenPluginManager mavenPluginManager,

    }

    private void disableOnPresentOption(
            final CommandLine commandLine, final String option, final Consumer<Boolean> setting) {
        if (commandLine.hasOption(option)) {
            setting.accept(false);
        }
    }

    private void disableOnPresentOption(
            final CommandLine commandLine, final char option, final Consumer<Boolean> setting) {

     * described.
     */
    static class UnknownRepositoryLayout implements ArtifactRepositoryLayout {

        private final String id;

        private final ArtifactRepositoryLayout fallback;

        UnknownRepositoryLayout(String id, ArtifactRepositoryLayout fallback) {
            this.id = id;
            this.fallback = fallback;
        }

      barrier.await(1, SECONDS);
      executor.execute(barrierTask);
      // timeout means the second task wasn't even tried
      barrier.await(1, SECONDS);
    } finally {
      service.shutdown();
    }
  }

  public void testRejectedExecutionThrownWithMultipleCalls() throws Exception {
    CountDownLatch latch = new CountDownLatch(1);

              nextEvent.subscribers.next().dispatchEvent(nextEvent.event);
            }
          }
        } finally {
          dispatching.remove();
          queue.remove();
        }
      }
    }

    private static final class Event {
      private final Object event;
      private final Iterator<Subscriber> subscribers;

      private Event(Object event, Iterator<Subscriber> subscribers) {