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[Python-Dev] Rename time.steady(strict=True) to time.monotonic()?

Jeffrey Yasskin jyasskin at gmail.com
Sat Mar 24 06:37:45 CET 2012 
On Fri, Mar 23, 2012 at 4:25 PM, Victor Stinner
<victor.stinner at gmail.com> wrote:
> Hi,
>
> time.steady(strict=True) looks to be confusing for most people, some
> of them don't understand the purpose of the flag and others don't like
> a flag changing the behaviour of the function.
>
> I propose to replace time.steady(strict=True) by time.monotonic().
> That would avoid the need of an ugly NotImplementedError: if the OS
> has no monotonic clock, time.monotonic() will just not exist.
>
> So we will have:
>
> - time.time(): realtime, can be adjusted by the system administrator
> (manually) or automatically by NTP
> - time.clock(): monotonic clock on Windows, CPU time on UNIX
> - time.monotonic(): monotonic clock, its speed may or may not be
> adjusted by NTP but it only goes forward, may raise an OSError
> - time.steady(): monotonic clock or the realtime clock, depending on
> what is available on the platform (use monotonic in priority). may be
> adjusted by NTP or the system administrator, may go backward.

Please don't use the word "steady" for something different from what
C++ means by it. C++'s term means "may not be adjusted at all, even by
NTP; proceeds at as close to the rate of real time as the system can
manage" (paraphrased). If the consensus in the Python community is
that a C++-style "steady" clock is unnecessary, then feel free not to
define it. If the consensus is that "monotonic" already means
everything C++ means by "steady", that's fine with me too. I mentioned
it because I thought it might be worth looking at what other languages
were doing in this space, not because I thought it was a nice word
that you should attach your own definitions to.

Jeffrey
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