Two quick Posix questions
February 15, 2004 05:37 PM
1) Is there an equivalent Posix call for timeGetTime()? I want to be able to time a function to the millisecond level (at least). Is it clock_gettime(CLOCK_REALTIME, ×pec) and then look at timespec''s tv_nsec member?
2) Is there a set of Posix documentation available that is as good as MSDN or the Java API docs? What I''ve downloaded is IEEE Std 1003.1-2001, but is there something nicer? For instance, I don''t see where structures are listed all in a nice list (klike all the system interfaces are). I have to click on clock_gettime(), then click on time.h link and scroll to see the bit about the timespec structure.
Thanks,
Jeff
February 15, 2004 05:44 PM
Another option I''ve seen is:
clock_t clock();
which returns the CPU time used since the process was invoked (I think). You need to divide the result by CLOCKS_PER_SEC to get the time in seconds, so I assume I''d go:
(clock()*1000)/CLOCK_PER_SEC
to get the value in milliseconds...
Anyone? Anyone?
Regards,
Jeff
clock_t clock();
which returns the CPU time used since the process was invoked (I think). You need to divide the result by CLOCKS_PER_SEC to get the time in seconds, so I assume I''d go:
(clock()*1000)/CLOCK_PER_SEC
to get the value in milliseconds...
Anyone? Anyone?
Regards,
Jeff
164
February 15, 2004 05:44 PM
1) Yes, but you should compare the seconds value as well, you never know if the last frame took more than a second to render.
2) "man clock_gettime" seems to work well for me (under linux).
2) "man clock_gettime" seems to work well for me (under linux).
February 15, 2004 06:05 PM
Abdulla, do you know about clock()?
This is under the mistaken impression that I KNOW about this function already...what if I want to browse around for functions starting with clock_? Then I want to see what a timespec struct is about?
quote: Original post by abdulla
2) "man clock_gettime" seems to work well for me (under linux).
This is under the mistaken impression that I KNOW about this function already...what if I want to browse around for functions starting with clock_? Then I want to see what a timespec struct is about?
1,099
February 15, 2004 07:30 PM
then use google.
an clock(), IIRC, may return one of:
(a) time since the program started
(b) time the program has executed in the processor.
I kinda suspect (b), which would mean you get seconds of time after minutes of running... (potentially)
an clock(), IIRC, may return one of:
(a) time since the program started
(b) time the program has executed in the processor.
I kinda suspect (b), which would mean you get seconds of time after minutes of running... (potentially)
164
February 15, 2004 11:47 PM
You can always do "man -a clock*", which is actually how I found it, I have no idea why I did that, guess I was bored one day. 
124
February 16, 2004 04:56 AM
quote: Original post by rypyr
This is under the mistaken impression that I KNOW about this function already...what if I want to browse around for functions starting with clock_? Then I want to see what a timespec struct is about?
man -k clock
or
apropos clock
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