{
    tensorflow::mutex_lock l(execution_mutex_);
    while (execution_state_ != ExecutionState::kIdle) {
      // If there's already a pending execution, wait until Join finishes before
      // starting on the next operation.
      finished_join_.wait(l);
    }
    context_ = context;
    operation_name_ = operation_name;
    step_id_ = step_id;
    op_inputs_ = inputs;
    attributes_ = attributes;