[Python-Dev] A couple of PEP 418 comments

Victor Stinner victor.stinner at gmail.com
Fri Apr 13 18:29:10 CEST 2012

> The descriptions should really stress the scope of the result's
> validity. My guess (or wish :-)) would be:
> - time.monotonic(): system-wide results, comparable from one process to
>  another
> - time.perf_counter(): process-wide results, comparable from one thread
>  to another (?)
> - time.process_time(): process-wide, by definition

time.monotonic() and time.perf_counter() are process-wide on Windows
older than Vista because of GetTickCount() overflow, on other OSes,
they are system-wide.

> It would also be nice to know if some systems may be unable to
> implement time.monotonic().

You can find such information in the following section:

All OSes provide a monotonic clock, except GNU/Hurd. You mean that it
should be mentioned in the time.monotonic() section?

>> GetTickCount() has an precision of 55 ms on Windows 9x.
> Do we care? :) Precision under recent Windows variants (XP or later)
> would be more useful.

You can get the precision on Windows Seven in the following table:

I will move the precision of monotonic clock of Windows 9x info into this table.


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