}

    @Override
    protected Executor executor() {
      transitionStates.add(state());
      return directExecutor();
    }
  }

  // Functional tests using real thread. We only verify publicly visible state.
  // Interaction assertions are done by the single-threaded unit tests.

  private static class DefaultService extends AbstractIdleService {
    @Override

  static <E extends @Nullable Object> Set<E> newHashSetWithExpectedSize(int expectedSize) {
    return Sets.newHashSetWithExpectedSize(expectedSize);
  }

  /** Returns the platform preferred implementation of a thread-safe hash set. */
  static <E> Set<E> newConcurrentHashSet() {
    return ConcurrentHashMap.newKeySet();
  }

  /**
   * Returns the platform preferred implementation of an insertion ordered set based on a hash

 * abused as a cache (i.e. for storing values that can be re-calculated) to avoid memory exhaustion.
 * <p>
 * <strong>Note:</strong> Actual implementations must be thread-safe.
 *
 * @see Session#getData()
 * @since 4.0.0
 */
@Experimental
@ThreadSafe
@Provider
public interface SessionData {

    /**
     * Associates the specified session data with the given key.

        if (metadataFile.length() == 0) {
            if (!metadataFile.delete()) {
                // sleep for 10ms just in case this is windows holding a file lock
                try {
                    Thread.sleep(10);
                } catch (InterruptedException e) {
                    // ignore
                }
                metadataFile.delete(); // if this fails, forget about it, we'll try to overwrite it anyway so no need

        try ( SmbFile f = getDefaultShareRoot() ) {
            checkConnection(f);
            while ( true ) {
                f.list();
                Thread.sleep(5000);
            }

        }
    }

      @Override
      public void run() {}
    }

    public static final class DummyThreadFactory implements ThreadFactory, Serializable {
      @Override
      public Thread newThread(Runnable r) {
        return new Thread(r);
      }
    }

    public static final class DummyExecutor implements Executor, Serializable {
      @Override
      public void execute(Runnable command) {}
    }
  }

  }

  /**
   * Returns a new, empty builder for {@link ImmutableLongArray} instances, sized to hold up to
   * {@code initialCapacity} values without resizing. The returned builder is not thread-safe.
   *
   * <p><b>Performance note:</b> When feasible, {@code initialCapacity} should be the exact number
   * of values that will be added, if that knowledge is readily available. It is better to guess a

            try {
                if ( retries != 1 ) {
                    // backoff, but don't delay the first attempt as there are various reasons that can be fixed
                    // immediately
                    Thread.sleep(500 + RAND.nextInt(1000));
                }
            }
            catch ( InterruptedException e ) {
                log.debug("interrupted sleep in send", e);
            }

  }

  /**
   * Returns a new, empty builder for {@link ImmutableIntArray} instances, sized to hold up to
   * {@code initialCapacity} values without resizing. The returned builder is not thread-safe.
   *
   * <p><b>Performance note:</b> When feasible, {@code initialCapacity} should be the exact number
   * of values that will be added, if that knowledge is readily available. It is better to guess a

  // (as in the case of ConstOp kernel creation on GPU, which involves copying a
  // CPU tensor to GPU).
  // Setting a larger thread pool does not help with the Swift caller, as we use
  // a different TFE context for each thread of execution (for running graph
  // functions, and their send/recvs corountines).
  config.set_inter_op_parallelism_threads(1);

  TF_Buffer* ret = TF_NewBuffer();