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GeezerVison is showing github.com — gh-115637 clarify that time.perf_counter cannot go backwards by anarcat · Pull Request #115638 · python/cpython

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@anarcat

@anarcat anarcat commented Feb 18, 2024 •
edited by github-actions Bot
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I'm not completely sure about this, but it seems to me this counter is also designed to avoid jumping backwards on (say) daylight saving or clock changes. It's kind of hinted to in the current description, but reading PEP 418 it's very clear that it's part of the intention, as it falls back to time.monotonic() apart from on nt.

  • Issue: time.perf_counter() should state more clearly (or deny) that it is monotonic #115637

📚 Documentation preview 📚: https://cpython-previews--115638.org.readthedocs.build/

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@anarcat
anarcat requested review from abalkin and pganssle as code owners February 18, 2024 21:32
@ghost

ghost commented Feb 18, 2024 •
edited by ghost
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@bedevere-app bedevere-app Bot added awaiting review docs Documentation in the Doc dir skip news labels Feb 18, 2024
@bedevere-app bedevere-app Bot mentioned this pull request Feb 18, 2024
time.perf_counter() should state more clearly (or deny) that it is monotonic #115637
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@anarcat
clarify that time.perf_counter cannot go backwards
03a0708 
I'm not completely sure about this, but it seems to me this counter is *also* designed to avoid jumping backwards on (say) daylight saving or clock changes. It's kind of hinted to in the current description, but reading PEP 418 it's very clear that it's part of the intention, as it falls back to time.monotonic() apart from on `nt`.
@anarcat
anarcat force-pushed the patch-1 branch from 8c2d2e4 to 03a0708 Compare February 18, 2024 21:37
@anarcat
anarcat marked this pull request as draft February 19, 2024 14:31
@bedevere-app bedevere-app Bot removed the awaiting review label Feb 19, 2024
@willingc

willingc commented Feb 23, 2024

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@arnarcat Thanks for the draft PR. Given your discussion with @vstinner on the issue, do you want to move this out of draft or close the PR?
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@anarcat

anarcat commented Feb 24, 2024

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i'm not sure. i guess i'm waiting on other folks to weigh in on the issue first...
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@vstinner

vstinner commented Mar 14, 2024

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See also issue gh-88494.

I created PR gh-116781 to use QueryPerformanceCounter() for time.monotonic().
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@vstinner vstinner mentioned this pull request Mar 14, 2024
gh-88494: Use QueryPerformanceCounter() for time.monotonic() #116781
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github-actions Bot commented Apr 15, 2026

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This PR is stale because it has been open for 30 days with no activity.
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@github-actions github-actions Bot added the stale Stale PR or inactive for long period of time. label Apr 15, 2026
@anarcat
anarcat marked this pull request as ready for review April 15, 2026 13:14
@anarcat
anarcat requested a review from StanFromIreland as a code owner April 15, 2026 13:14
@bedevere-app bedevere-app Bot added the awaiting review label Apr 15, 2026
@StanFromIreland
Merge branch 'main' into patch-1
66e9aa4
@github-actions github-actions Bot removed the stale Stale PR or inactive for long period of time. label May 12, 2026
StanFromIreland
StanFromIreland reviewed Jun 5, 2026
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Comment thread Doc/library/time.rst

.. impl-detail::

On CPython, use the same clock as :func:`time.monotonic` and is a

@StanFromIreland StanFromIreland Jun 5, 2026

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This is documented here.

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@anarcat anarcat Jun 8, 2026

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but that's different from the patch I was suggesting though. below is an "implementation detail" and above is more of a specification...

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@StanFromIreland

StanFromIreland commented Jun 5, 2026

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Closing as per note on issue.
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@StanFromIreland StanFromIreland closed this Jun 5, 2026
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@StanFromIreland StanFromIreland StanFromIreland left review comments
@pganssle pganssle Awaiting requested review from pganssle pganssle is a code owner
@abalkin abalkin Awaiting requested review from abalkin

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@anarcat @willingc @vstinner @StanFromIreland
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