device_(device),
        stream_executor_(stream_executor),
        stream_handle_(nullptr) {}
  ~CStream() override {
    parent()->BlockHostUntilDone(this).IgnoreError();
    parent()->DeallocateStream(this);
    Destroy();
  }

  absl::Status Create() {
    tensorflow::TF_StatusPtr c_status(TF_NewStatus());
    stream_executor_->create_stream(device_, &stream_handle_, c_status.get());

    return stream_executor_->host_callback(&device_, stream_handle,
                                           &HostCallbackTrampoline, ctx);
  }
  void DeallocateStream(Stream* stream) override {
    static_cast<CStream*>(stream)->Destroy();
  }
  absl::Status BlockHostForEvent(Stream* stream, Event* event) {
    OwnedTFStatus c_status(TF_NewStatus());