#ifdef WIN32
	#include <Windows.h>
	class windowsTiming
	{
		public:
			windowsTiming(void);
		
		public:
			typedef struct 
			{
			  signed __int64 nTicksCnt;
			} timeType;
		
			inline double diff_ms(timeType& p_start, timeType& p_end)
			{
				return (double(p_end.nTicksCnt-p_start.nTicksCnt)/double(m_TickPerSecond)*1000.);
			};
			
			inline timeType getTime(void)
			{
				timeType res;
				QueryPerformanceCounter((LARGE_INTEGER*)&res.nTicksCnt);
				return res;
			};
	
		private:
			signed __int64 m_TickPerSecond;
	};

	typedef windowsTiming HWTiming;

#else
	#include <time.h>
	class LinuxTiming {
		public:
			LinuxTiming() {};
			
		public:
			typedef timespec timeType;
			
			static inline timeType getTime()
			{
				timeType t;
				clock_gettime(CLOCK_REALTIME, &t);
				return t;
			}
			
			static inline double diff_ms(timeType& t1, timeType& t2)
			{
				return ((t2.tv_sec-t1.tv_sec)*1000.0 + (t2.tv_nsec-t1.tv_nsec)/1000000.0); 
			}
	};

	typedef LinuxTiming HWTiming;
#endif

#ifdef WIN32
		windowsTiming::windowsTiming(void)
		{
			QueryPerformanceFrequency((LARGE_INTEGER*)&m_TickPerSecond);
		};
#endif

HWTiming timeMeasurer;

HWTiming::timeType  startTime = timeMeasurer.getTime();

.... do you're thing !-)

HWTiming::timeType  endTime = timeMeasurer.getTime();

double delta = timeMeasurer.diff_ms(endTime, startTime);