LARGE_INTEGER结构实际上是一个联合。如果你的编译器具有内置支持64位整数，使用QuadPart成员中存储的64位整数。否则，使用LowPart和H...
4 调用WIN API中的QueryPerformanceCounter [DllImport("kernel32.dll ")] static extern bool QueryPerformanceCounter...用法： long a = 0; QueryPerformanceFrequency(ref a);long b = 0, c = 0; QueryPerformanceCounter(ref b);...Thread.Sleep(2719); QueryPerformanceCounter(ref c); Console.WriteLine((c - b) / (decimal)a); //单位秒...实际上它里面就是将QueryPerformanceCounter、QueryPerformanceFrequency两个WIN API封装了一下，如果硬件支持高精度，就调用QueryPerformanceCounter...timer.GetCount(); Thread.Sleep(2719); Console.WriteLine((timer.GetCount() - ss) / (decimal)a); 缺点：和QueryPerformanceCounter
QueryPerformanceFrequency()技术特点供WIN9X使用的高精度定时器： QueryPerformanceFrequency()和QueryPerformanceCounter()...函数的原形是： BOOL QueryPerformanceFrequency(LARGE_INTEGER *lpFrequency); BOOL QueryPerformanceCounter (LARGE_INTEGER...接着在需要严格计时的事件发生前和发生之后分别调用QueryPerformanceCounter()，利用两次获得的计数之差和时钟频率，就可以计算出事件经历的精确时间。...qt1,qt2; double dft,dff,dfm; QueryPerformanceFrequency(&litmp);//获得时钟频率 dff=(double)litmp.QuadPart; QueryPerformanceCounter...(&litmp);//获得初始值 qt1=litmp.QuadPart;Sleep(100); QueryPerformanceCounter(&litmp);//获得终止值 qt2=litmp.QuadPart
QueryPerformanceFrequency() – 技术特点供WIN9X使用的高精度定时器：QueryPerformanceFrequency()和QueryPerformanceCounter...函数的原形是： BOOL QueryPerformanceFrequency(LARGE_INTEGER *lpFrequency); BOOL QueryPerformanceCounter...接着在需要严格计时的事件发生前和发生之后分别调用QueryPerformanceCounter()，利用两次获得的计数之差和时钟频率，就可以计算出事件经历的精确时间。...double dft,dff,dfm; QueryPerformanceFrequency(&litmp);//获得时钟频率 dff=(double)litmp.QuadPart; QueryPerformanceCounter...(&litmp);//获得初始值 qt1=litmp.QuadPart;Sleep(100); QueryPerformanceCounter(&litmp);//获得终止值 qt2=
阅读本文也可以了解到 QueryPerformanceCounter、GetSystemTimeAsFileTime 等方法的差异。...GetSystemTimePreciseAsFileTime QueryInterruptTimePrecise, QueryUnbiasedInterruptTimePrecise 基于系统性能计数器（QPC）的 API QueryPerformanceCounter...一般情况下使用的 QueryPerformanceCounter，内核驱动开发者使用的 KeQueryPerformanceCounter 和 .NET 开发者使用的 System.Diagnostics.Stopwatch...QueryPerformanceCounter 得到的值是 Ticks，单位是 100 ns。...– The Old New Thing windows平台时间函数性能比较QueryPerformanceCounter，GetTickCount，ftime，time,GetLocalTime，GetSystemTimeAsFileTime
方式七：对于精确度要求更高的定时操作，则应该使用QueryPerformanceFrequency()和 QueryPerformanceCounter()函数。...QueryPerformanceFrequency()函数和QueryPerformanceCounter() 函数的原型如下： BOOL QueryPerformanceFrequency...(LARGE_INTEGER ＊lpFrequency); BOOL QueryPerformanceCounter(LARGE_INTEGER ＊lpCount); 数据类型ARGE_INTEGER...(&litmp); QPart1 = litmp.QuadPart; // 获得初始值 do { QueryPerformanceCounter...(&litmp); QPart1 = litmp.QuadPart; // 获得初始值 Sleep(100); QueryPerformanceCounter
在windows下可以通过QueryPerformanceFrequency()和QueryPerformanceCounter()等系列函数来实现计时器的功能。...::time_in() { QueryPerformanceFrequency(&litmp);//获得时钟频率 dff = (double)litmp.QuadPart; QueryPerformanceCounter...(&litmp);//获得初始值 qt1 = litmp.QuadPart; return 1; } double CTimer::time_out() { QueryPerformanceCounter
cvMorphologyEx(Src, Dest, NULL, kernel0, CV_MOP_DILATE, 1); cvReleaseStructuringElement(&kernel0); QueryPerformanceCounter...; IplConvKernel *kernel1 = cvCreateStructuringElementEx(30, 30, 15, 15, CV_SHAPE_ELLIPSE); QueryPerformanceCounter...cvMorphologyEx(Src, Dest, NULL, kernel1, CV_MOP_DILATE, 1); cvReleaseStructuringElement(&kernel1); QueryPerformanceCounter...1000); IplConvKernel *kernel2 = cvCreateStructuringElementEx(15, 15, 7, 7, CV_SHAPE_ELLIPSE); QueryPerformanceCounter...1000); IplConvKernel *kernel3 = cvCreateStructuringElementEx(14, 14, 7, 7, CV_SHAPE_ELLIPSE); QueryPerformanceCounter
Src = (float*)malloc(Length * sizeof(float)); float* Dest = (float*)malloc(Length * sizeof(float)); QueryPerformanceCounter...mm_loadu_ps(Src + X); __m128 DstV = _mm_exp_ps(SrcV); _mm_storeu_ps(Dest + X, DstV); } } QueryPerformanceCounter...nBeginTime.QuadPart) * 1000 / (double)nFreq.QuadPart;//（开始-停止）/频率即为秒数，精确到小数点后6位 printf("%f \n", time); QueryPerformanceCounter...mm_loadu_ps(Src + X); __m128 DstV = _mm_fexp_ps(SrcV); _mm_storeu_ps(Dest + X, DstV); } } QueryPerformanceCounter
获取机器内部计时器的时钟 QueryPerformanceFrequency(&freq); QueryPerformanceCounter(&start); …… //数据传输 QueryPerformanceCounter...(&stop); 头文件为，函数原型为： BOOL QueryPerformanceFrequency(LARGE_INTEGER*lpFrequency); BOOL QueryPerformanceCounter...(LARGE_INTEGER*lpCount); 在定时前先调用QueryPerformanceFrequency函数获得机器内部计时器的时钟频率，然后在严格计时的时间发生前后调用QueryPerformanceCounter...(&start);write_device(h2c0_device,FPGA_DDR_START_ADDR+0x20000000,size,h2c_align_mem_tmp); QueryPerformanceCounter...(&start); read_device(c2h0_device,FPGA_DDR_START_ADDR+0x10000000,size,c2h_align_mem_tmp); QueryPerformanceCounter
GetThreadTimes(hthread, &c, &e, &k, &u);//获取线程时间 //(更)精确的时间计算 LARGE_INTEGER start, end; bret = QueryPerformanceCounter...时钟次数 LARGE_INTEGER frequency; bret = QueryPerformanceFrequency(&frequency);//时钟频率 bret = QueryPerformanceCounter
LARGE_INTEGER freq; LARGE_INTEGER start; LARGE_INTEGER end; QueryPerformanceFrequency(&freq); QueryPerformanceCounter...(&start); //获取一帧数据 pFrame = cvQueryFrame(pCapture); QueryPerformanceCounter(&end); //发送数据给
int CTimer::time_in() { QueryPerformanceFrequency(&litmp);//获得时钟频率 dff = (double)litmp.QuadPart; QueryPerformanceCounter...(&litmp);//获得初始值 qt1 = litmp.QuadPart; return 1; } double CTimer::time_out() { QueryPerformanceCounter
要获取高精度时间，可以使用 BOOL QueryPerformanceFrequency(LARGE_INTEGER *lpFrequency)获取系统的计数器的频率 BOOL QueryPerformanceCounter...m_nBeginTime; LARGE_INTEGER nEndTime; QueryPerformanceFrequency(&m_nFreq); // 获取时钟周期 QueryPerformanceCounter...(&m_nBeginTime); // 获取时钟计数 Sleep(100); QueryPerformanceCounter(&nEndTime); cout << (
3、要获取高精度时间，可以使用 BOOL QueryPerformanceFrequency(LARGE_INTEGER *lpFrequency)获取系统的计数器的频率 BOOL QueryPerformanceCounter...m_nBeginTime; LARGE_INTEGER nEndTime; QueryPerformanceFrequency(&m_nFreq); // 获取时钟周期 QueryPerformanceCounter...(&m_nBeginTime); // 获取时钟计数 Sleep(100); QueryPerformanceCounter(&nEndTime); cout <<
系统原生API是QueryPerformanceCounter (QPC)。...在.NET中提供了System.Diagnostics.Stopwatch类获取高精度时间戳，它内部也是通过QueryPerformanceCounter (QPC)进行高精度计时。...QueryPerformanceCounter (QPC)使用硬件计数器作为其基础。硬件计时器由三个部分组成：时钟周期生成器、计数时钟周期的计数器和检索计数器值的方法。...这三个分量的特征决定了QueryPerformanceCounter (QPC)的分辨率、精度、准确性和稳定性[1]。它的精度可以高达几十纳秒，用来实现高精度定时器基本没什么问题。
系统原生API是QueryPerformanceCounter (QPC)。...在.NET中提供了System.Diagnostics.Stopwatch类获取高精度时间戳，它内部也是通过QueryPerformanceCounter (QPC)进行高精度计时。...QueryPerformanceCounter (QPC)使用硬件计数器作为其基础。硬件计时器由三个部分组成：时钟周期生成器、计数时钟周期的计数器和检索计数器值的方法。...这三个分量的特征决定了QueryPerformanceCounter (QPC)的分辨率、精度、准确性和稳定性。 它的精度可以高达几十纳秒，用来实现高精度定时器基本没什么问题。
如果需要更高精度的时间测量，可以使用 QueryPerformanceCounter()。...如果需要更大的计时范围或更高精度的时间测量，可以使用 GetTickCount64() 或 QueryPerformanceCounter()。
QueryPerformanceCounter(&liStart); 91....QueryPerformanceCounter(&liFinish); 93. OutputTime(&liStart, &liFinish); 94. 95....QueryPerformanceCounter(&liStart); 111. hr = pstm->Read(pv, cb, NULL); 112....QueryPerformanceCounter(&liFinish); 113. OutputTime(&liStart, &liFinish); 114....QueryPerformanceCounter(&liStart); 120. hr = pstm->Write(pv, cb, NULL); 121.
创建互斥体：CreateMutexA或者CreateMutexW 打开互斥体：OpenMutexA或者OpenMutexW CPU延时：Sleep 获取精确的定时器计时：QueryPerformanceCounter
云服务器
ICP备案
对象存储
即时通信 IM
云直播
