ecs/include/ecs/core/utils/counter_blocker.h

#pragma once

#include <mutex>
#include <condition_variable>
#include <ecs/config.h>

beg_namespace_ecs_core_utils
{

    struct counter_blocker
    {
    private:
        std::mutex                  _mutex;
        std::condition_variable     _cond_var;
        size_t                      _counter;

    public:
        inline counter_blocker(size_t counter) noexcept
            : _counter(counter)
            { }

        inline void increment() noexcept
        {
            std::lock_guard lock(_mutex);
            assert(_counter > 0);
            ++_counter;
        }

        inline void decrement_and_notify_one() noexcept
        {
            std::lock_guard lock(_mutex);
            assert(_counter > 0);
            --_counter;
            _cond_var.notify_one();
        }

        inline void decrement_and_notify_all() noexcept
        {
            std::lock_guard lock(_mutex);
            assert(_counter > 0);
            --_counter;
            _cond_var.notify_all();
        }

        template<typename T_func>
        inline void execute_and_wait_until_zero(T_func&& func) noexcept
        {
            func();
            std::unique_lock lock(_mutex);
            _cond_var.wait(lock, [this]{ return (_counter == 0); });
        }
    };

}
end_namespace_ecs_core_utils