Class DelayedStream

core/src/main/java/io/grpc/internal/DelayedStream.java:44–551

A stream that queues requests before the transport is available, and delegates to a real stream implementation when the transport is available. ClientStream itself doesn't require thread-safety. However, the state of DelayedStream may be internally altered by different threads, t

 * necessary.
 */
class DelayedStream implements ClientStream {
  private final String bufferContext;
  /** {@code true} once realStream is valid and all pending calls have been drained. */
  private volatile boolean passThrough;
  /**
   * Non-{@code null} iff start has been called. Used to assert methods are called in appropriate
   * order, but also used if an error occurs before {@code realStream} is set.
   */
  private ClientStreamListener listener;
  /** Must hold {@code this} lock when setting. */
  private ClientStream realStream;
  @GuardedBy("this")
  private Status error;
  @GuardedBy("this")
  private List<Runnable> pendingCalls = new ArrayList<>();
  @GuardedBy("this")
  private DelayedStreamListener delayedListener;
  @GuardedBy("this")
  private long startTimeNanos;
  @GuardedBy("this")
  private long streamSetTimeNanos;
  // No need to synchronize; start() synchronization provides a happens-before
  private List<Runnable> preStartPendingCalls = new ArrayList<>();

  /**
   * Create a delayed stream with debug context {@code bufferContext}. The context is what this
   * stream is delayed by (e.g., "connecting", "call_credentials").
   */
  public DelayedStream(String bufferContext) {
    this.bufferContext = checkNotNull(bufferContext, "bufferContext");
  }

  @Override
  public void setMaxInboundMessageSize(final int maxSize) {
    checkState(listener == null, "May only be called before start");
    preStartPendingCalls.add(new Runnable() {
      @Override
      public void run() {
        realStream.setMaxInboundMessageSize(maxSize);
      }
    });
  }

  @Override
  public void setMaxOutboundMessageSize(final int maxSize) {
    checkState(listener == null, "May only be called before start");
    preStartPendingCalls.add(new Runnable() {
      @Override
      public void run() {
        realStream.setMaxOutboundMessageSize(maxSize);
      }
    });
  }

  @Override
  public void setDeadline(final Deadline deadline) {
    checkState(listener == null, "May only be called before start");
    preStartPendingCalls.add(new Runnable() {