[Python-Dev] A couple of PEP 418 comments (original) (raw)

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.perfcounter(): process-wide results, comparable from one thread  to another (?) - time.processtime(): 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: http://www.python.org/dev/peps/pep-0418/#clock-monotonic-clock-monotonic-raw-clock-boottime

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: http://www.python.org/dev/peps/pep-0418/#monotonic-clocks

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

Victor

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