Is cpu clock time returned by have to be exactly same among runs?

Question

I have big project written in C++. It might have some stability problems (i.e. random runtime), but I\'m not sure about it. I understand that execution time, measured by wal

Answer 1

OP says is using Windows 7, if that is MSVC the man page says

The clock function tells how much wall-clock time the calling process has used. Note that this is not strictly conformant with ISO C99, which specifies net CPU time as the return value. To obtain CPU time, use the Win32 GetProcessTimes function.

That is why the apparent execution time is inconsistent.