MFC measure function in milliseconds

Question

How can i count the millisecond a certain function (called repeatedly) takes ?
I thought of:
CTime::GetCurrentTM() before,
CTime::GetCurrentTM() after,

And then insert the result to CTimeSpan diff = after - before.
Finally store that diff to global member that sum all diffs since i want to know the total time this function spent.

but it will give the answer in seconds and not milliseconds.

score 6 · Accepted Answer · answered Dec 25 '12 at 11:11

6

MFC is C++, right?

If so, you can just use clock().

#include <ctime>

clock_t time1 = clock();
// do something heavy
clock_t time2 = clock();
clock_t timediff = time2 - time1;

float timediff_sec = ((float)timediff) / CLOCKS_PER_SEC;

This will usually give you millisecond precision.

answered Dec 25 '12 at 11:11

Tom van der Woerdt

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`timediff_sec * 1000` is the millisecond value, otherwise it shows second value. – Fredrick Gauss May 10 '18 at 09:33

score 1 · Answer 2 · answered Mar 25 '14 at 23:51

1

If you are using MFC, the nice way is to use WIN API. And since you are worried just to calculate the time difference, the below function might suit you perfectly.

GetTickCount64()

directly returns the number of milli seconds that has elapsed since the system was started.

If you don't plan to keep your system up long (precisely more than 49.7 days), little bit faster version - GetTickCount() function

answered Mar 25 '14 at 23:51

Mohan

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Because it is based on when system starts, it seems to me this approach has a problem: when a computer very rarely restarts: it may overflow the counter! – sergiol May 04 '16 at 17:28

score 0 · Answer 3 · answered May 04 '16 at 17:56

The COleDateTime is known to internally work based on milliseconds, because it stores timestamp on its m_dt variable, which is of DATE type, so having resolution for the intended purpose.

I can suggest you to base your time on

DATE now= (DATE) COleDateTime::GetCurrentTime();

and after do the respective calculations.

MFC measure function in milliseconds

3 Answers3