PEP 418: Add link to Monoclock library and an old article on Windows clocks

Mention also another issue of QueryPerformanceCounter()

pep-0418.txt

@@ -411,6 +411,9 @@ Bugs:
   each processor.  The bug was fixed in Windows XP SP2.
 * Issues with processor with variable frequency: the frequency is changed
   depending on the workload to reduce memory consumption.
+* Chromium don't use QueryPerformanceCounter() on Athlon X2 CPUs (model 15)
+  because "QueryPerformanceCounter is unreliable" (see base/time_win.cc in
+  Chromium source code)
 
 .. _KB896256: http://support.microsoft.com/?id=896256
 .. _KB274323: http://support.microsoft.com/?id=274323
@@ -905,6 +908,9 @@ Libraries exposing monotonic clocks:
 * `python-monotonic-time
   <http://code.google.com/p/python-monotonic-time/>`_ (`github
   <https://github.com/gavinbeatty/python-monotonic-time>`_)
+* `Monoclock.nano_count()
+  <https://github.com/ludios/Monoclock>`_ uses clock_gettime(CLOCK_MONOTONIC)
+  and returns a number of nanoseconds
 * `monotonic_clock <https://github.com/ThomasHabets/monotonic_clock>`_
 * `Perl: Time::HiRes <http://perldoc.perl.org/Time/HiRes.html>`_
   exposes clock_gettime(CLOCK_MONOTONIC)
@@ -961,6 +967,8 @@ Time:
   <http://www.ibm.com/developerworks/library/i-seconds/>`_: How the
   IBM High Resolution Time Stamp Facility accurately measures itty
   bits of time
+* `Win32 Performance Measurement Options
+  <http://drdobbs.com/windows/184416651>`_ by Matthew Wilson, May 01, 2003
 
 
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