Method Transition

be/src/kudu/util/threadpool.cc:291–338

}

void ThreadPoolToken::Transition(State new_state) {
#ifndef NDEBUG
  CHECK_NE(state_, new_state);

  switch (state_) {
    case State::IDLE:
      CHECK(new_state == State::RUNNING ||
            new_state == State::QUIESCED);
      if (new_state == State::RUNNING) {
        CHECK(!entries_.empty());
      } else {
        CHECK(entries_.empty());
        CHECK_EQ(active_threads_, 0);
      }
      break;
    case State::RUNNING:
      CHECK(new_state == State::IDLE ||
            new_state == State::QUIESCING ||
            new_state == State::QUIESCED);
      CHECK(entries_.empty());
      if (new_state == State::QUIESCING) {
        CHECK_GT(active_threads_, 0);
      }
      break;
    case State::QUIESCING:
      CHECK(new_state == State::QUIESCED);
      CHECK_EQ(active_threads_, 0);
      break;
    case State::QUIESCED:
      CHECK(false); // QUIESCED is a terminal state
      break;
    default:
      LOG(FATAL) << "Unknown token state: " << state_;
  }
#endif

  // Take actions based on the state we're entering.
  switch (new_state) {
    case State::IDLE:
    case State::QUIESCED:
      not_running_cond_.Broadcast();
      break;
    default:
      break;
  }

  state_ = new_state;
}

const char* ThreadPoolToken::StateToString(State s) {
  switch (s) {