[issue41303] perf_counter result does not count system sleep time in Mac OS

[nooB]

nooB <nsharish.mit at gmail.com> added the comment:

> perf_counter documentation says "It does include time elapsed during sleep and is system-wide." where "sleep" here means time.sleep()

Apologies for misinterpreting the documentation. A clock function that includes system suspend time can be useful. Consider this as a feature request.

I noticed that on both Linux and Mac OS, the functions time.monotonic and time.perf_counter are exactly same. They do not count time elapsed during suspend.

--- CODE -----

import time
for clock in "monotonic", "perf_counter":
    print(f"{clock}: {time.get_clock_info(clock)}")

--- MAC OUTPUT ----

monotonic: namespace(adjustable=False, implementation='mach_absolute_time()', monotonic=True, resolution=1e-09)
perf_counter: namespace(adjustable=False, implementation='mach_absolute_time()', monotonic=True, resolution=1e-09)

--- LINUX OUTPUT --

monotonic: namespace(adjustable=False, implementation='clock_gettime(CLOCK_MONOTONIC)', monotonic=True, resolution=1e-09)
perf_counter: namespace(adjustable=False, implementation='clock_gettime(CLOCK_MONOTONIC)', monotonic=True, resolution=1e-09)

--------------

In Windows, perf_counter uses "QueryPerformanceCounter()" which includes "the time when the machine was in a sleep state such as standby, hibernate, or connected standby"
refer: https://docs.microsoft.com/en-us/windows/win32/sysinfo/acquiring-high-resolution-time-stamps

I learnt that "mach_continuous_time()" in Mac OS, "clock_gettime(CLOCK_BOOTTIME)" in Linux and "QueryPerformanceCounter()" in Windows all include system suspend time. It would be nice if perf_counter can be tweaked to provide similar behaviour across platforms. If it is not recommended, the mentioned functions can be exposed as a separate clock function.

Thanks.

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue41303>
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