[Pierre-Marie Baty]

Originally Posted by botmeister

This line has a small error in it:

time_in_seconds = (float) current_clock / CLOCKS_PER_SEC;

After a rollover event, the elapsed time in seconds is actually:

time_in_seconds = (float) ( current_clock + 1 ) / CLOCKS_PER_SEC;

...and one bug, one!
Thanks.
But instead of adding +1 to current_clock ONLY IF a rollover has happened, I'd rather add 1 to LONG_MAX (sounds more logical) - no worry, LONG_MAX won't overflow, since I'll cast it to (double) beforehand.

rollover_difference = ((double) LONG_MAX + 1) / CLOCKS_PER_SEC * rollover_count;

This line I cannot understand:

rollover_difference = (float) 286331153 / CLOCKS_PER_SEC * rollover_count;


What does 286331153 represent? If we are calculating the number of seconds elapsed during each rollover, then you should be using 2147483647 (2^31 - 1) as the constant (if I typed it in right). You should use the macro LONG_MAX to make the code machine independant.

Would you believe I don't understand myself how this number managed to land in the middle of my code ??? I remember having used Window's calculator to find out what the maximal value for a 32-bit integer would be, but looks like the Windows calculator is not trustable enough even for things like this o_O

(float) 286331153 / CLOCKS_PER_SEC is an inline division of two constants, you may as well precalculate this. The compiler may do this for you, but it would be cleaner to precalculate elsewhere.

good idea, thank you !

You may want to replace the data type "float" with "double" because float does not have enough precision to get exact timing conversions in all cases.

alright, you're right again, will do.

Thanks a lot for the review, it's much faster when you get your code reviewed by people who have not spent the day with the nose above it, pointing mistakes is so easy Tell me if I can give you a hand in return someday

[edit] Where is LONG_MAX defined ? I can't find this macro anywhere...