Semaphore.hpp

#pragma once

// Use Win or Posix
#ifdef WIN32
#include <windows.h>
#define LMAXIMUMCOUNT 99999999 
#else
#ifndef POSIX
#warning POSIX will be used (but you did not define it)
#endif
#include <semaphore.h>
#endif

namespace ParaEngine
{
    class Semaphore{
    protected:

#ifdef WIN32
        HANDLE _sem;    
#else
        sem_t _sem;     
#endif

    public:
        Semaphore( int in_init = 0 ){
#ifdef WIN32
            _sem = CreateSemaphore(0,in_init,LMAXIMUMCOUNT,0);
#else
            sem_init(&_sem,0,in_init);
#endif
        }

        Semaphore(const Semaphore &in_sem){
            int value = in_sem.value();
#ifdef WIN32
            _sem = CreateSemaphore(0,value,LMAXIMUMCOUNT,0);
#else
            sem_init(&_sem,0,value);
#endif
        }

        void operator=(const Semaphore &in_sem){
            reset(in_sem.value());
        }

        virtual ~Semaphore(){
#ifdef WIN32
            CloseHandle(_sem);
#else
            sem_destroy(&_sem);
#endif
        }

        bool wait() const {
#ifdef WIN32
            return WaitForSingleObject(static_cast< HANDLE >(_sem),INFINITE) == 0x00000000L;
#else
            return sem_wait(const_cast<sem_t*>(&_sem)) == 0;
#endif
        }

        bool post(){
#ifdef WIN32
            return ReleaseSemaphore(static_cast< HANDLE >(_sem),1,0) != 0;
#else
            return sem_post(&_sem) == 0;
#endif
        }

        int value() const{
#ifdef WIN32
            long value = -1;
            ReleaseSemaphore(static_cast<const HANDLE>(_sem),0,&value);
            return value;
#else
            int value = -1;
            sem_getvalue(const_cast<sem_t*>(&_sem),&value);
            return value;
#endif
        }

        void reset( int in_init = 0 ){
#ifdef WIN32
            CloseHandle(_sem);
            _sem = CreateSemaphore(0,in_init,LMAXIMUMCOUNT,0);
#else
            sem_destroy(&_sem);
            sem_init(&_sem,0,in_init);
#endif
        }
    };
}