精确计时MSVC

• #include<iostream>
• #include "functional"
• #include "windows.h"
• using namespace std;
• #include <WinBase.h>
• long long calculateMS(std::function<void()> processFunc)
• {
• long long _value;
• LARGE_INTEGER freq, _start, _end;
• QueryPerformanceFrequency(&freq);
• QueryPerformanceCounter(&_start);
• processFunc();
• QueryPerformanceCounter(&_end);
• _value = (_end.QuadPart - _start.QuadPart) * 1000 / freq.QuadPart;
• return _value;
• }
• long long calculateUS(std::function<void()> processFunc)
• {
• long long _value;
• LARGE_INTEGER freq, _start, _end;
• QueryPerformanceFrequency(&freq);
• QueryPerformanceCounter(&_start);
• processFunc();
• QueryPerformanceCounter(&_end);
• _value = (_end.QuadPart - _start.QuadPart) *1000*1000 / freq.QuadPart;
• return _value;
• }
• int main(int argc, char *argv[])
• {
• printf("%d us\r\n\n", calculateUS([=]()
• {
• int a[9999];
• for (int i = 0; i != 9999; i++)
• {
• a[i] = i;
• }
• }));
• system("pause");
• return 0;
• }

#include<iostream>
#include "functional"
#include "windows.h"
using namespace std;

#include <WinBase.h>  



long long calculateMS(std::function<void()> processFunc)
{
	long long _value;
	LARGE_INTEGER freq, _start, _end;
	QueryPerformanceFrequency(&freq);
	QueryPerformanceCounter(&_start);

	processFunc();

	QueryPerformanceCounter(&_end);
	_value = (_end.QuadPart - _start.QuadPart) * 1000 / freq.QuadPart;

	return _value;
}



long long calculateUS(std::function<void()> processFunc)
{
	long long _value;
	LARGE_INTEGER freq, _start, _end;
	QueryPerformanceFrequency(&freq);
	QueryPerformanceCounter(&_start);

	processFunc();

	QueryPerformanceCounter(&_end);
	_value = (_end.QuadPart - _start.QuadPart) *1000*1000 / freq.QuadPart;

	return _value;
}


int main(int argc, char *argv[])
{
	printf("%d us\r\n\n", calculateUS([=]()
	{
		int a[9999];
		for (int i = 0; i != 9999; i++)
		{
			a[i] = i;

		}
	}));















	system("pause");
	return 0;
}