Method ThreadProc

src/common/thread_pool.h:181–234

    return NULL;
  }
  void ThreadProc() {
    while (true) {
      Task task;
      MutexLock lock(&mutex_, "ThreadProc");
      while (time_queue_.empty() && queue_.empty() && !stop_) {
        work_cv_.Wait("ThreadProcWait");
      }
      if (stop_) {
        break;
      }
      // Timer task
      if (!time_queue_.empty()) {
        int64_t now_time = get_micros();
        BGItem bg_item = time_queue_.top();
        int64_t wait_time = bg_item.exe_time - now_time;  // in us
        if (wait_time <= 0) {
          time_queue_.pop();
          BGMap::iterator it = latest_.find(bg_item.id);
          if (it != latest_.end() && it->second.exe_time == bg_item.exe_time) {
            schedule_cost_sum_ += now_time - bg_item.exe_time;
            schedule_count_++;
            task = bg_item.task;
            latest_.erase(it);
            running_task_ids_.insert(bg_item.id);
            mutex_.Unlock();
            task(bg_item.id);
            mutex_.Lock("ThreadProcRelock");
            task_cost_sum_ += get_micros() - now_time;
            task_count_++;
            running_task_ids_.erase(bg_item.id);
          }
          continue;
        } else if (queue_.empty() && !stop_) {
          work_cv_.TimeWaitInUs(wait_time, "ThreadProcTimeWait");
          continue;
        }
      }
      // Normal task;
      if (!queue_.empty()) {
        task = queue_.front().task;
        int64_t exe_time = queue_.front().exe_time;
        queue_.pop_front();
        --pending_num_;
        int64_t start_time = get_micros();
        schedule_cost_sum_ += start_time - exe_time;
        schedule_count_++;
        mutex_.Unlock();
        task(0);
        mutex_.Lock("ThreadProcRelock2");
        task_cost_sum_ += get_micros() - start_time;
        task_count_++;
      }
    }
  }

 private:
  struct BGItem {