New submission from Kristján Valur Jónsson <krist...@ccpgames.com>:
The attached patch does three things: " - Abstract the condition variable used by ceval_gil.h into a separate file, condvar.h. It now defines a PyMUTEX_T, PyCOND_T and associated functions. This file can be used by different parts of the python core. - Implement locking on windows using custom structures based on condition variables, rather than using a semaphore kernel object. This avoids kernel transitions for uncontensted locks and provides a large speedup for windows. - Add a condition variable implementation using native primitives for builds targeted for Vista. Experimental and disabled by default. " Using this locking mechanism on windows results in a 60% speedup of using uncontested locks, due to the removal of the necessary kernel transition that is required by regular semaphore objects. Before: D:\pydev\hg\cpython3\PCbuild\amd64>.\python.exe -m timeit -s "from _thread import allocate_lock; l=allocate_lock()" "l.acquire();l .release()" 1000000 loops, best of 3: 0.731 usec per loop After: D:\pydev\hg\cpython3\PCbuild\amd64>.\python.exe -m timeit -s "from _thread import allocate_lock; l=allocate_lock()" "l.acquire();l .release()" 1000000 loops, best of 3: 0.27 usec per loop ---------- components: Interpreter Core, Windows files: 77369.patch keywords: patch messages: 162545 nosy: kristjan.jonsson, loewis, pitrou priority: normal severity: normal status: open title: Optimize python Locks on Windows type: enhancement versions: Python 3.3 Added file: http://bugs.python.org/file25867/77369.patch _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue15038> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
