Function async_call

tensorboard/util/grpc_util.py:143–155

Invokes the gRPC future and orchestrates it via the AsyncCallFuture.

(handler)

    async_future = AsyncCallFuture(completion_event)

    def async_call(handler):
        """Invokes the gRPC future and orchestrates it via the AsyncCallFuture."""
        future = api_method.future(
            request,
            timeout=_GRPC_DEFAULT_TIMEOUT_SECS,
            metadata=version_metadata(),
        )
        # Ensure we set the active future before invoking the done callback, to
        # avoid the case where the done callback completes immediately and
        # triggers completion event while async_future still holds the old
        # future.
        async_future._set_active_future(future)
        future.add_done_callback(handler)

    # retry_handler is the continuation of the `async_call`.  It should:
    #   * If the grpc call succeeds: trigger the `completion_event`.