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bpo-45429: Support CREATE_WAITABLE_TIMER_HIGH_RESOLUTION if possible #29203

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Merged
corona10 merged 9 commits into from
Nov 16, 2021
Merged

bpo-45429: Support CREATE_WAITABLE_TIMER_HIGH_RESOLUTION if possible #29203

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39bb0b1
bpo-45429: Support CREATE_WAITABLE_TIMER_HIGH_RESOLUTION if possible
corona10 Oct 24, 2021
06850bc
bpo-45429: Check timer flags is avaialbe when the module exec phase
corona10 Oct 24, 2021
b807832
bpo-45429: nit
corona10 Oct 24, 2021
efe9a4c
bpo-45429: nit
corona10 Oct 24, 2021
88dc924
bpo-45429: Address code review
corona10 Oct 24, 2021
8fb1819
bpo-45429: nit
corona10 Oct 24, 2021
eb07306
bpo-45429: Address code review
corona10 Oct 24, 2021
ba18321
bpo-45429: Address code review
corona10 Nov 16, 2021
4c6c904
bpo-45429: Update whatsnew 3.11
corona10 Nov 16, 2021
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4 changes: 4 additions & 0 deletions Doc/whatsnew/3.11.rst
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Original file line number Diff line number Diff line change
Expand Up @@ -272,6 +272,10 @@ time
a resolution of 1 millisecond (10\ :sup:`-3` seconds).
(Contributed by Benjamin Szőke and Victor Stinner in :issue:`21302`.)

* On Windows, :func:`time.sleep` now uses a waitable timer which supports high-resolution timers.
In Python 3.10, the best resolution was 1 ms, from Python 3.11 it's now smaller than 1 ms.

@vstinner vstinner Nov 16, 2021

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Maybe try to merge this this item with the previous one.

(Contributed by Dong-hee Na and Eryk Sun in :issue:`45429`.)

unicodedata
-----------

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2 changes: 2 additions & 0 deletions Misc/NEWS.d/next/Library/2021-10-25-01-22-49.bpo-45429.VaEyN9.rst
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@@ -0,0 +1,2 @@
On Windows, :func:`time.sleep` now uses a waitable timer which supports
high-resolution timers. Patch by Dong-hee Na and Eryk Sun.
40 changes: 31 additions & 9 deletions Modules/timemodule.c
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Expand Up @@ -408,6 +408,13 @@ static PyStructSequence_Desc struct_time_type_desc = {
static int initialized;
static PyTypeObject StructTimeType;

#if defined(MS_WINDOWS)
#ifndef CREATE_WAITABLE_TIMER_HIGH_RESOLUTION
#define CREATE_WAITABLE_TIMER_HIGH_RESOLUTION 0x00000002
#endif

static DWORD timer_flags = (DWORD)-1;
#endif

static PyObject *
tmtotuple(struct tm *p
Expand Down Expand Up @@ -2017,6 +2024,23 @@ time_exec(PyObject *module)
utc_string = tm.tm_zone;
#endif

#if defined(MS_WINDOWS)
if (timer_flags == (DWORD)-1) {
DWORD test_flags = CREATE_WAITABLE_TIMER_HIGH_RESOLUTION;
HANDLE timer = CreateWaitableTimerExW(NULL, NULL, test_flags,
TIMER_ALL_ACCESS);
if (timer == NULL) {
// CREATE_WAITABLE_TIMER_HIGH_RESOLUTION is not supported.
timer_flags = 0;
}
else {
// CREATE_WAITABLE_TIMER_HIGH_RESOLUTION is supported.
timer_flags = CREATE_WAITABLE_TIMER_HIGH_RESOLUTION;
CloseHandle(timer);
}
}
#endif

return 0;
}

Expand Down Expand Up @@ -2150,20 +2174,18 @@ pysleep(_PyTime_t timeout)
// SetWaitableTimer(): a negative due time indicates relative time
relative_timeout.QuadPart = -timeout_100ns;

HANDLE timer = CreateWaitableTimerW(NULL, FALSE, NULL);
HANDLE timer = CreateWaitableTimerExW(NULL, NULL, timer_flags,
TIMER_ALL_ACCESS);
if (timer == NULL) {
PyErr_SetFromWindowsErr(0);
return -1;
}

if (!SetWaitableTimer(timer, &relative_timeout,
// period: the timer is signaled once
0,
// no completion routine
NULL, NULL,
// Don't restore a system in suspended power
// conservation mode when the timer is signaled.
FALSE))
if (!SetWaitableTimerEx(timer, &relative_timeout,
0, // no period; the timer is signaled once
NULL, NULL, // no completion routine
NULL, // no wake context; do not resume from suspend
0)) // no tolerable delay for timer coalescing
{
PyErr_SetFromWindowsErr(0);
goto error;
Expand Down