线程延时

    在进行多线程编程时，经常需要进行一些线程的延时，而对于Sleep 是不准确的，所以需要获取震片时间钟进行延时。代码如下:

ULONG GetTimeDis(struct tm first, struct tm second)    

{
    return abs((first.tm_hour * 3600 + first.tm_min * 60 + first.tm_sec)
        - (second.tm_hour * 3600 + second.tm_min * 60 + second.tm_sec));
}
//延时 微妙级别
void Delay(ULONG ulMicroSeconds)
{
    LARGE_INTEGER  timeStop; 
    LARGE_INTEGER  timeStart; 
    LARGE_INTEGER  Freq; 
    ULONG  ulTimeToWait;
    
	__try 
	{ 
		if (!QueryPerformanceFrequency( &Freq ))
			return;

		ulTimeToWait = Freq.QuadPart * ulMicroSeconds / 1000 / 1000; 
		QueryPerformanceCounter ( &timeStart ); 
		timeStop = timeStart; 
		while( timeStop.QuadPart - timeStart.QuadPart < ulTimeToWait ) 
		{ 
			QueryPerformanceCounter( &timeStop ); 
		}
	} 
	__except( EXCEPTION_EXECUTE_HANDLER ) 
	{ 
		AfxMessageBox( "延迟错误") ; 
	}
}