Jim*_*Jim 8 c++ c++11 c++-chrono
我一直在研究各种游戏计时循环方法,例如Glenn Fiedler和DeWitter.由于我自己的C++知识限制,我发现关键领域难以理解.有了这个我开始尝试实现我自己的方法....我想一个好方法来尝试理解这些方法的一些东西.
[edit1:我正在使用CodeBlocks IDE和minGW-w64(x64-4.8.1-posix-seh-rev5)作为编译器]
[edit2:修改代码和输出窗口以包含第3个计时器,QueryPerformanceCounter]
在尝试完成此操作时,我遇到了以下问题:
最小代码:
#include <chrono>
#include <iostream>
#include <windows.h>
#include <stdio.h>
using namespace std;
using namespace chrono;
LARGE_INTEGER startqpc, stopqpc, li;
double PCFreq = 0.0;
void print()
{
for (int p=0; p<1000000; ) p += 1; //adjust till ms (steady) returns 1-2ms
}
int main()
{
for(int x=0; x<200; x += 1)
{
steady_clock::time_point start = steady_clock::now();
auto timePoint1 = chrono::high_resolution_clock::now();
if(!QueryPerformanceFrequency(&li))
cout << "QueryPerformanceFrequency failed!\n";
PCFreq = double(li.QuadPart)/1000.0;
QueryPerformanceCounter(&startqpc);
print();
steady_clock::time_point finish = steady_clock::now();
auto timePoint2 = chrono::high_resolution_clock::now();
QueryPerformanceCounter(&stopqpc);
auto elapsedTime(timePoint2 - timePoint1);
double diff = (stopqpc.QuadPart - startqpc.QuadPart)/PCFreq;
cout << "Elapsed time: "
<< duration_cast<milliseconds>(finish - start).count() << "ms (steady) "
<< chrono::duration_cast<chrono::duration<float, milli >> (elapsedTime).count() << "ms (hires) "
<< diff << " (qpc) \n";
}
}
为了进行比较,上面的代码使用了两个定时器.
在我的电脑上,这个输出如下:
Elapsed time: 1ms (steady) 0ms (hires) 1.8429 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.8429 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1ms (steady) 15.6ms (hires) 1.85152 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1ms (steady) 15.6001ms (hires) 1.85557 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.59283 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.25573 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1ms (steady) 15.6ms (hires) 1.85072 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84263 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84263 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1ms (steady) 15.6ms (hires) 1.85422 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84263 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84263 (qpc)
Elapsed time: 1ms (steady) 15.6001ms (hires) 1.85099 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.31582 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1ms (steady) 15.6ms (hires) 1.84964 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.52466 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 2ms (steady) 15.6ms (hires) 2.25169 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84263 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.26974 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84991 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84667 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.89518 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.87874 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.92213 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.87605 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84263 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.03126 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.87659 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.88467 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.24899 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.30316 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.23579 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.93263 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.23552 (qpc)
Elapsed time: 2ms (steady) 15.6ms (hires) 2.42118 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.24522 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.23471 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.23848 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.93425 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.9329 (qpc)
Elapsed time: 1ms (steady) 15.6001ms (hires) 1.85126 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.35355 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.23687 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.23633 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.2374 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.23498 (qpc)
Elapsed time: 1ms (steady) 15.6ms (hires) 1.85449 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.0097 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.15441 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.93263 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.93452 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.93425 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.23579 (qpc)
Elapsed time: 2ms (steady) 15.6ms (hires) 2.04554 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.1121 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.01779 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.07222 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.9329 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.93425 (qpc)
Elapsed time: 1ms (steady) 15.6001ms (hires) 1.95015 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.95177 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84587 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84425 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84533 (qpc)
Elapsed time: 1ms (steady) 15.6ms (hires) 1.85233 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.88278 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84667 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84533 (qpc)
Elapsed time: 1ms (steady) 15.6ms (hires) 1.88629 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84506 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.8456 (qpc)
Elapsed time: 1ms (steady) 15.6ms (hires) 1.8588 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.06225 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.23633 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.93317 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.06009 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84533 (qpc)
Elapsed time: 1ms (steady) 15.6001ms (hires) 1.86284 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.93425 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.02803 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.26839 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.93398 (qpc)
Elapsed time: 1ms (steady) 15.6ms (hires) 1.93641 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.93371 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.93344 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.9329 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.02345 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.08731 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.9356 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84506 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.93398 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.09 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.93371 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.03072 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.19213 (qpc)
Elapsed time: 1ms (steady) 15.6ms (hires) 1.85287 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.9321 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.93344 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.93317 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.93344 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.93263 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.42711 (qpc)
Elapsed time: 1ms (steady) 15.6001ms (hires) 1.9418 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.9356 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.08947 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.9329 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.93614 (qpc)
Elapsed time: 2ms (steady) 15.6ms (hires) 2.27702 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.93614 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.93317 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.08974 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.92698 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.93317 (qpc)
Elapsed time: 2ms (steady) 15.6ms (hires) 2.09054 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.96066 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.96093 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.8456 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.8456 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.8456 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84533 (qpc)
Elapsed time: 1ms (steady) 15.6001ms (hires) 1.91835 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.8456 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84587 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.8456 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1ms (steady) 15.6ms (hires) 1.85233 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84425 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.93317 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.93317 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.23552 (qpc)
Elapsed time: 1ms (steady) 15.6ms (hires) 1.93102 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.07033 (qpc)
Elapsed time: 2ms (steady) 0ms (hires) 2.09405 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.9329 (qpc)
Elapsed time: 1ms (steady) 0ms (hires) 1.93263 (qpc)
Process returned 0 (0x0) execution time : 0.484 s
Press any key to continue.
使用duration_cast<microseconds>(finish - start).count()/1000.0了我们看下面的steady_clock: -
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84263 (qpc)
Elapsed time: 1.843ms (steady) 0ms (hires) 1.84317 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1.846ms (steady) 0ms (hires) 1.84694 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.8456 (qpc)
Elapsed time: 1.877ms (steady) 0ms (hires) 1.87685 (qpc)
Elapsed time: 1.916ms (steady) 15.6ms (hires) 1.9162 (qpc)
Elapsed time: 1.906ms (steady) 0ms (hires) 1.90623 (qpc)
Elapsed time: 1.905ms (steady) 0ms (hires) 1.90515 (qpc)
Elapsed time: 1.909ms (steady) 0ms (hires) 1.90919 (qpc)
Elapsed time: 1.905ms (steady) 0ms (hires) 1.90542 (qpc)
Elapsed time: 1.905ms (steady) 0ms (hires) 1.90488 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1.943ms (steady) 15.6ms (hires) 1.94287 (qpc)
Elapsed time: 1.872ms (steady) 0ms (hires) 1.87281 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1.846ms (steady) 15.6001ms (hires) 1.8464 (qpc)
Elapsed time: 1.875ms (steady) 0ms (hires) 1.87497 (qpc)
Elapsed time: 2.033ms (steady) 0ms (hires) 2.03449 (qpc)
Elapsed time: 1.922ms (steady) 0ms (hires) 1.92293 (qpc)
Elapsed time: 1.922ms (steady) 0ms (hires) 1.92293 (qpc)
Elapsed time: 1.926ms (steady) 0ms (hires) 1.92698 (qpc)
Elapsed time: 2.004ms (steady) 15.6ms (hires) 2.00485 (qpc)
Elapsed time: 1.847ms (steady) 0ms (hires) 1.84748 (qpc)
Elapsed time: 1.847ms (steady) 0ms (hires) 1.84748 (qpc)
Elapsed time: 1.848ms (steady) 0ms (hires) 1.84856 (qpc)
Elapsed time: 1.849ms (steady) 0ms (hires) 1.84937 (qpc)
Elapsed time: 2.299ms (steady) 0ms (hires) 2.29938 (qpc)
Elapsed time: 3.497ms (steady) 15.6ms (hires) 3.49664 (qpc)
Elapsed time: 3.528ms (steady) 0ms (hires) 3.52843 (qpc)
Elapsed time: 2.299ms (steady) 0ms (hires) 2.29857 (qpc)
Elapsed time: 1.849ms (steady) 0ms (hires) 1.84937 (qpc)
Elapsed time: 1.848ms (steady) 0ms (hires) 1.84856 (qpc)
Elapsed time: 1.848ms (steady) 0ms (hires) 1.84856 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84263 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84263 (qpc)
Elapsed time: 1.854ms (steady) 0ms (hires) 1.85395 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1.843ms (steady) 0ms (hires) 1.84371 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.8429 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1.843ms (steady) 0ms (hires) 1.8429 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1.861ms (steady) 0ms (hires) 1.86123 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 2.058ms (steady) 0ms (hires) 2.05848 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1.881ms (steady) 0ms (hires) 1.88144 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.843ms (steady) 0ms (hires) 1.84371 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84209 (qpc)
Elapsed time: 1.896ms (steady) 0ms (hires) 1.89653 (qpc)
Elapsed time: 1.842ms (steady) 0ms (hires) 1.84236 (qpc)
Elapsed time: 1.843ms (steady) 0ms (hires) 1.84398 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84425 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1.886ms (steady) 0ms (hires) 1.88656 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.85ms (steady) 15.6ms (hires) 1.85099 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84506 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1.848ms (steady) 15.6001ms (hires) 1.84883 (qpc)
Elapsed time: 2.066ms (steady) 0ms (hires) 2.06683 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84506 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84506 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84506 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.888ms (steady) 0ms (hires) 1.88817 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84506 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84506 (qpc)
Elapsed time: 1.853ms (steady) 15.6ms (hires) 1.85341 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 2.056ms (steady) 0ms (hires) 2.05605 (qpc)
Elapsed time: 1.88ms (steady) 0ms (hires) 1.8809 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.882ms (steady) 0ms (hires) 1.88224 (qpc)
Elapsed time: 1.849ms (steady) 15.6ms (hires) 1.85018 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84506 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84506 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 2.243ms (steady) 0ms (hires) 2.24333 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84506 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84506 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.849ms (steady) 15.6ms (hires) 1.85018 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84506 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84506 (qpc)
Elapsed time: 2.109ms (steady) 0ms (hires) 2.10914 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84533 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84506 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84506 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84506 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84506 (qpc)
Elapsed time: 2.006ms (steady) 0ms (hires) 2.00647 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84506 (qpc)
Elapsed time: 1.852ms (steady) 15.6ms (hires) 1.8526 (qpc)
Elapsed time: 2.534ms (steady) 0ms (hires) 2.53463 (qpc)
Elapsed time: 2.368ms (steady) 0ms (hires) 2.3681 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84533 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84533 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84506 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84506 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1.853ms (steady) 15.6ms (hires) 1.85368 (qpc)
Elapsed time: 1.843ms (steady) 0ms (hires) 1.84371 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84533 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84425 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84506 (qpc)
Elapsed time: 1.852ms (steady) 15.6ms (hires) 1.85233 (qpc)
Elapsed time: 1.849ms (steady) 0ms (hires) 1.8491 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84587 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84425 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84425 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1.891ms (steady) 15.6001ms (hires) 1.89168 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84506 (qpc)
Elapsed time: 1.846ms (steady) 0ms (hires) 1.84587 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84425 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84506 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.846ms (steady) 15.6ms (hires) 1.8464 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84587 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.848ms (steady) 15.6ms (hires) 1.84829 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84506 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.8456 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84425 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84506 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.846ms (steady) 15.6ms (hires) 1.84614 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84425 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.8456 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84425 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84479 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84506 (qpc)
Elapsed time: 1.872ms (steady) 15.6001ms (hires) 1.87281 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84452 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84587 (qpc)
Elapsed time: 1.844ms (steady) 0ms (hires) 1.84425 (qpc)
Elapsed time: 1.845ms (steady) 0ms (hires) 1.84479 (qpc)
Process returned 0 (0x0) execution time : 0.499 s
Press any key to continue
Notice how the high resolution clock fluctuates between 0 and 15.6ms and notice the steady_clock comparison.
The issue I have is that is that if I were to implement a fixed-time game loop where the update() code updates entity positions at exactly 1000/60 (60 update cycles a second) i.e. every 16.666etc ms - then this is very close to the returned hires timer fluctuating value! The real problem is that if I also implement an accumulator in order to accommodate both game loop frame times that are under 1000/60ms and any leftover once update() has completed, the update loop is entered sooner - and at irregular time points - than it should.
上面的最小代码是否存在问题,如果没有,我是否应该关注任何适当的固定时间实现？另外,如果相关,有没有办法隔离程序/线程,以免它被系统IRQ或其他轮询事件中断？我猜测雇佣计时器可能会受到这种干扰.
Ben*_*igt 10
标准库的实现中存在一个错误std::chrono.
我知道Visual C++中有一个这样的错误,不知道你使用的是什么编译器,但如果支持std::chrono是最近添加的,它们可能仍然有一些缺陷.
如果您使用的是Visual C++,您应该注意:
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