On Fri, 2002-08-30 at 19:49, Mike Bresnahan wrote: > Thanks, Chris. My concern with using gettimeofday() is that I don't want to > pay the performance cost of doing a timezone calculation. In fact I don't > require the real time. I simply want to measure the elapsed time of an > operation. A simple counter running at the clock frequency of the processor > would suffice; as long as I can also determine the clock frequency. I > understand that the pentium processor has such a function and it requires > only a small amount of assembly code to access it, however I'd prefer to not > write the assembly code if I don't have to. What timezone calculation? As near as I can tell, gettimeofday returns the time in UTC, which is what the kernel keeps its time in. If your application is so sensitive that the overhead of a system call is too much, then I don't know what to say. It sounds like the hand hacked bit of assembly is really your only choice. Even that is fraught with peril in the form of kernel timer scheduling interrupts and possibly even another process running while you're trying to do your timing. Have fun (if at all possible), -- The best we can hope for concerning the people at large is that they be properly armed. -- Alexander Hamilton -- Eric Hopper (hopper at omnifarious.org http://www.omnifarious.org/~hopper) -- -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 228 bytes Desc: This is a digitally signed message part Url : http://shadowknight.real-time.com/pipermail/tclug-devel/attachments/20020831/70aa09b2/attachment.pgp