logiops/src/logid/util/task.h

/*
 * Copyright 2019-2020 PixlOne
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */
#ifndef LOGID_TASK_H
#define LOGID_TASK_H

#include <functional>
#include <memory>
#include <future>
#include "ExceptionHandler.h"

namespace logid
{
    class task
    {
    public:
        enum Status
        {
            Waiting,
            Running,
            Completed
        };

        explicit task(const std::function<void()>& function,
                        const std::function<void(std::exception&)>&
                        exception_handler={[](std::exception& e)
                                           {ExceptionHandler::Default(e);}});

        Status getStatus();

        void run(); // Runs synchronously
        void wait();
        void waitStart();
        std::future_status waitFor(std::chrono::milliseconds ms);

        /* This function spawns a new task into the least used worker queue
         * and forgets about it.
         */
        static void spawn(const std::function<void()>& function,
                          const std::function<void(std::exception&)>&
                          exception_handler={[](std::exception& e)
                                             {ExceptionHandler::Default(e);}});

    private:
        std::shared_ptr<std::function<void()>> _function;
        std::shared_ptr<std::function<void(std::exception&)>>
                _exception_handler;
        std::atomic<Status> _status;
        std::condition_variable _status_cv;
        std::packaged_task<void()> _task_pkg;
        std::future<void> _future;
    };
}

#endif //LOGID_TASK_H