BasicThread.h

/*--------------------------------------------------------------------------------------------
Copyright (c) 2019, NDEVR LLC
tyler.parke@ndevr.org
  __    __   ____     _____ __     __  _______
 |  \  |  | |  __ \  |  ___|\ \   / / |   __  \
 |   \ |  | | |  \ \ | |___  \ \ / /  |  |__)  |
 |  . \|  | | |__/ / | |___   \ V /   |   _   /
 |  |\    |_|_____/__|_____|___\_/____|  | \  \
 |__| \__________________________________|  \__\
 
Subject to the terms of the Enterprise+ Agreement, NDEVR hereby grants 
Licensee a limited, non-exclusive, non-transferable, royalty-free license 
(without the right to sublicense) to use the API solely for the purpose of 
Licensee's internal development efforts to develop applications for which 
the API was provided.
 
The above copyright notice and this permission notice shall be included in all 
copies or substantial portions of the Software.
 
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE.
 
Library: Base
File: BasicThread
Included in API: True
Author(s): Tyler Parke
 *-----------------------------------------------------------------------------------------**/
#pragma once
#include <NDEVR/Thread.h>
#include "DLLInfo.h"
#include <NDEVR/ConcurrentOperation.h>
#include <functional>
namespace NDEVR
{
 
#if NDEVR_SUPPORTS_THREADING
    class NDEVR_BASE_API BasicThread : public Thread
    {
        static uint04 s_os_number_of_threads; 
    public:
        explicit BasicThread(const StringView& name, const bool& is_loop, const std::function<void()>& callback);
        void run() override
        {
            m_function();
        }

        static void splitThread(const std::function<void()>& callback_a, const std::function<void()>& callback_b);
        static void splitThread(const StringView& split_name, const std::function<void()>& callback_a, const std::function<void()>& callback_b);

        template<uint04 t_max_number_of_threads>
        static typename std::enable_if<t_max_number_of_threads <= 32, void>::type ThreadLoop(uint04 number_of_loops, const std::function<void(uint04 index)>& callback)
        {
            volatile uint04 loops_performed = 0;
            switch (getMin(t_max_number_of_threads, number_of_loops, s_os_number_of_threads))
            {
            case 0: break;
            case 1: ThreadLoop<1>(number_of_loops, loops_performed, callback); break;
            case 2: ThreadLoop<2>(number_of_loops, loops_performed, callback); break;
            case 3: ThreadLoop<3>(number_of_loops, loops_performed, callback); break;
            case 4: ThreadLoop<4>(number_of_loops, loops_performed, callback); break;
            case 5: ThreadLoop<5>(number_of_loops, loops_performed, callback); break;
            case 6: ThreadLoop<6>(number_of_loops, loops_performed, callback); break;
            case 7: ThreadLoop<7>(number_of_loops, loops_performed, callback); break;
            case 8: ThreadLoop<8>(number_of_loops, loops_performed, callback); break;
            case 9: ThreadLoop<9>(number_of_loops, loops_performed, callback); break;
            case 10: ThreadLoop<10>(number_of_loops, loops_performed, callback); break;
            case 11: ThreadLoop<11>(number_of_loops, loops_performed, callback); break;
            case 12: ThreadLoop<12>(number_of_loops, loops_performed, callback); break;
            case 13: ThreadLoop<13>(number_of_loops, loops_performed, callback); break;
            case 14: ThreadLoop<14>(number_of_loops, loops_performed, callback); break;
            case 15: ThreadLoop<15>(number_of_loops, loops_performed, callback); break;
            case 16: ThreadLoop<16>(number_of_loops, loops_performed, callback); break;
            case 32: ThreadLoop<32>(number_of_loops, loops_performed, callback); break;
            default: lib_assert(false, "Invalid thread count"); return;
            }
        }

        template<uint04 t_max_number_of_threads>
        static void ThreadLoop(uint04 number_of_loops, volatile uint04& loops_performed, const std::function<void(uint04 index)>& callback)
        {
            if constexpr (t_max_number_of_threads == 1)
            {
                while (loops_performed < number_of_loops)
                {
                    uint04 loop = ConcurrentOperation::increment(loops_performed);
                    if(loop - 1 < number_of_loops)
                        callback(loop - 1);
                }
            }
            else
            {
                splitThread(
                    [&callback, &loops_performed, number_of_loops]
                    {
                        ThreadLoop<t_max_number_of_threads / 2>(number_of_loops, loops_performed, callback);
                    },
                    [&callback, &loops_performed, number_of_loops]
                    {
                        ThreadLoop<t_max_number_of_threads - (t_max_number_of_threads / 2)>(number_of_loops, loops_performed, callback);
                    });
            }
        }
    protected:
        std::function<void()> m_function; 
    };
#endif
}