getting elapsed time in milliseconds

[Thomas Baier]

Hi there,

I need to know how to get the elapsed time in milliseconds. I tried
time_t start,end;
time(start);
do_something();
time(end);

double dif = difftime(end, start);

but this only returns the elapsed time in seconds.
So how can I get it in milliseconds?


Thanks for hlep

Thomas

 

[WW]

I need to know how to get the elapsed time in milliseconds. I tried [SNIP]
So how can I get it in milliseconds?

By a high resolution timer facility provided by your operating system, if it
provides one. Not possible to do only using standard C++ language features.
Please post your question to a newsgroup dedicated to yiur
compiler/platform.

 

[Thomas Baier]

Thomas Baier wrote:

I'm working under Suse Linux 8.2 with g++. Maybe anybody in this newgroup
could answer my question now. Or could anybody tell me a good newsgroup to
post?


Thomas

 

[Alf P. Steinbach]

Thomas Baier wrote:

I'm working under Suse Linux 8.2 with g++. Maybe anybody in this newgroup
could answer my question now. Or could anybody tell me a good newsgroup to
post?

This group is not "please find a newsgroup for me".

Please don't post any more such questions (read the FAQ etc. about
topicality, in other words, RTFM).

That said, try [comp.os.linux.development.*].

 

[J. Campbell]

Hi there,

I need to know how to get the elapsed time in milliseconds. I tried
time_t start,end;
time(start);
do_something();
time(end);

double dif = difftime(end, start);

but this only returns the elapsed time in seconds.
So how can I get it in milliseconds?


Thanks for hlep

Thomas

The following will do what you want:


int main(){
int clo = clock();
//do stuff
cout << (clock() - clo) << endl;
return 0;
}

 

[Kevin Goodsell]

The following will do what you want:


int main(){
int clo = clock();
//do stuff
cout << (clock() - clo) << endl;
return 0;
}

clock() is not a function for retrieving elapsed (real) time, and it's
result is not measured in milliseconds. clock() gives *processor time*,
and the precision it uses depends on the implementation.

-Kevin

 

[J. Campbell]

clock() is not a function for retrieving elapsed (real) time, and it's
result is not measured in milliseconds. clock() gives *processor time*,
and the precision it uses depends on the implementation.

-Kevin

Thanks for the heads-up. On my implimentation, clock() returns
milliseconds with circa 15 ms precision, and I'd assumed (always
imprudent) that it worked the same across the board. I dug a little
and learned of the CLOCKS_PER_SEC constant, which will help a bit for
gross measurements. Thanks for keeping me on the
straight-and-narrow...