File px_worker_manager.hpp¶

File List > cubrid > src > query > parallel > px_worker_manager.hpp
/*
 *
 * Copyright 2016 CUBRID Corporation
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */

/*
 * px_worker_manager.hpp - module that manages parallel worker threads.
 */

#ifndef _PX_WORKER_MANAGER_HPP_
#define _PX_WORKER_MANAGER_HPP_

#if !defined (SERVER_MODE) && !defined (SA_MODE)
#error Belongs to server module
#endif /* !defined (SERVER_MODE) && !defined (SA_MODE) */

#include <atomic>

#include "thread_entry_task.hpp"    /* cubthread::entry_task */

namespace parallel_query
{
  class worker_manager
  {
    public:
      static worker_manager *try_reserve_workers (int num_workers);

      worker_manager();
      ~worker_manager();

      void release_workers ();
      void wait_workers ();
      void push_task (cubthread::entry_task *task);
      void pop_task ()
      {
    m_active_tasks.fetch_sub (1, std::memory_order_release);
      }
      int get_reserved_workers () const
      {
    return m_reserved_workers;
      }

    private:
      std::atomic<int> m_active_tasks;
      int m_reserved_workers;

      worker_manager (const worker_manager &) = delete;
      worker_manager &operator= (const worker_manager &) = delete;
  };
}

#endif /*_PX_WORKER_MANAGER_HPP_ */