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PEP 418: Try to fill the "Action on suspend" column

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Victor Stinner 2012-03-30 04:21:11 +02:00
parent 4dc3e314eb
commit a21dff29ba
1 changed files with 21 additions and 9 deletions
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pep-0418.txt
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@ -186,18 +186,18 @@ Summary
Table summarizing all monotonic clocks:
========================= =============== ================ =================
========================= =============== ================ ====================
Name Resolution Adjusted by NTP? Action on suspend
========================= =============== ================ =================
CLOCK_MONOTONIC_RAW 1 ns No ?
gethrtime 1 ns No ?
========================= =============== ================ ====================
CLOCK_MONOTONIC_RAW 1 ns No Stopped
gethrtime 1 ns No Not stopped
mach_absolute_time() 1 ns No ?
CLOCK_HIGHRES 1 ns No ?
CLOCK_MONOTONIC 1 ns Yes on Linux Stopped on Linux
QueryPerformanceCounter() 0.3 ns - 5 ns No ?
GetTickCount[64]() 1 ms - 15 ms No ?
QueryPerformanceCounter() 0.3 ns - 5 ns No Accuracy issue
GetTickCount[64]() 1 ms - 15 ms No Include suspend time
timeGetTime() 1 ms - 15 ms No ?
========================= =============== ================ =================
========================= =============== ================ ====================
mach_absolute_time
^^^^^^^^^^^^^^^^^^
@ -212,6 +212,10 @@ nanoseconds. According to the documentation (`Technical Q&A QA1398
is always equals to one and does never fail, even if the function may fail
according to its prototype.
mach_absolute_time() stops during a sleep on PowerPC CPU, but not on Intel CPU:
`Different behaviour of mach_absolute_time() on i386 / ppc
<http://lists.apple.com/archives/PerfOptimization-dev/2006/Jul/msg00024.html>`_.
mach_absolute_time() has a resolution of 1 nanosecond.
CLOCK_MONOTONIC, CLOCK_MONOTONIC_RAW
@ -319,6 +323,9 @@ adjusted by SetSystemTimeAdjustment(). MSDN documentation:
`GetTickCount() <http://msdn.microsoft.com/en-us/library/windows/desktop/ms724408(v=vs.85).aspx>`_,
`GetTickCount64() <http://msdn.microsoft.com/en-us/library/windows/desktop/ms724411(v=vs.85).aspx>`_.
The elapsed time retrieved by GetTickCount or GetTickCount64 includes time the
system spends in sleep or hibernation.
GetTickCount64() was added to Windows Vista and Windows Server 2008.
The clock resolution is 1 millisecond. Its accuracy is usually around 15 ms. It
@ -371,6 +378,9 @@ resetting or drifting by way of adjtime() or settimeofday(). The hires timer
is ideally suited to performance measurement tasks, where cheap, accurate
interval timing is required.
The linearity of gethrtime() is not preserved accross cpr suspend-resume cycle
(`Bug 4272663 <http://wesunsolve.net/bugid/id/4272663>`_).
Read the `gethrtime() manual page of Solaris 11
<http://docs.oracle.com/cd/E23824_01/html/821-1465/gethrtime-3c.html#scrolltoc>`_.
@ -455,13 +465,15 @@ See also pthread_getcpuclockid().
Windows: QueryUnbiasedInterruptTime
-----------------------------------
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Gets the current unbiased interrupt time from the biased interrupt time and the
current sleep bias amount. This time is not affected by power management sleep
transitions.
Is it monotonic?
The elapsed time retrieved by the QueryUnbiasedInterruptTime function includes
only time that the system spends in the working state.
QueryUnbiasedInterruptTime() is not monotonic.
QueryUnbiasedInterruptTime() was introduced in Windows 7.