AutoTickThread.h

/******************************************************************************
DSPatch - The Refreshingly Simple C++ Dataflow Framework
Copyright (c) 2025, Marcus Tomlinson
 
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#pragma once
 
#include <dspatch/Circuit.h>
 
#include <condition_variable>
#include <thread>
 
namespace DSPatch
{
namespace internal
{
 
 
class AutoTickThread final
{
public:
    NONCOPYABLE( AutoTickThread );
 
    inline AutoTickThread() = default;
 
    inline ~AutoTickThread()
    {
        Stop();
    }
 
    inline void Start( DSPatch::Circuit* circuit )
    {
        if ( !_stopped )
        {
            Resume();
            return;
        }
 
        _circuit = circuit;
 
        _stop = false;
        _stopped = false;
        _pause = false;
 
        _thread = std::thread( &AutoTickThread::_Run, this );
    }
 
    inline void Stop()
    {
        _stop = true;
 
        if ( _thread.joinable() )
        {
            _thread.join();
        }
    }
 
    inline void Pause()
    {
        if ( !_stopped && ++pauseCount == 1 )
        {
            std::unique_lock<std::mutex> lock( _resumeMutex );
            _pause = true;
            _pauseCondt.wait( lock );  // wait for pause
        }
    }
 
    inline void Resume()
    {
        if ( _pause && --pauseCount == 0 )
        {
            _pause = false;
            _resumeCondt.notify_all();
        }
    }
 
private:
    inline void _Run()
    {
        if ( _circuit )
        {
            while ( !_stop )
            {
                _circuit->Tick();
 
                if ( _pause )
                {
                    std::unique_lock<std::mutex> lock( _resumeMutex );
 
                    _pauseCondt.notify_all();
                    _resumeCondt.wait( lock );  // wait for resume
                }
            }
        }
 
        _stopped = true;
    }
 
    std::thread _thread;
    DSPatch::Circuit* _circuit = nullptr;
    int pauseCount = 0;
    bool _stop = false;
    bool _pause = false;
    bool _stopped = true;
    std::mutex _resumeMutex;
    std::condition_variable _resumeCondt, _pauseCondt;
};
 
}  // namespace internal
}  // namespace DSPatch