mirror of
https://github.com/kennethreitz/python-guide.git
synced 2026-06-05 23:00:18 +00:00
Ryan Day
70 lines
1.4 KiB
ReStructuredText
70 lines
1.4 KiB
ReStructuredText
Speed
|
|
=====
|
|
|
|
CPython, the most commonly used implementation of Python, is slow for CPU bound tasks. `PyPy`_ is fast.
|
|
|
|
.. todo:: Fill in stub for Speed comparisons
|
|
|
|
Context
|
|
:::::::
|
|
|
|
|
|
The GIL
|
|
-------
|
|
|
|
`The GIL`_ (Global Interpreter Lock) is how Python allows multiple threads to operate at the same time. Python's
|
|
memory management isn't entirely thread-safe, so the GIL is requried to prevents multiple threads from running
|
|
the same Python code at once.
|
|
|
|
David Beazley has a great `guide`_ on how the GIL operates. He also covers the `new GIL`_ in Python 3.2. His
|
|
results show that maximizing performance in a Python application requires a strong understanding of the GIL,
|
|
how it affects your specific application, how many cores you have, and where your application bottlenecks are.
|
|
|
|
C Extentions
|
|
------------
|
|
|
|
|
|
The GIL
|
|
-------
|
|
|
|
`Special care`_ must be taken when writing C extensions to make sure you register your threads
|
|
with the interpreter.
|
|
|
|
C Extentions
|
|
::::::::::::
|
|
|
|
|
|
Cython
|
|
------
|
|
|
|
|
|
Pyrex
|
|
-----
|
|
|
|
|
|
Shedskin?
|
|
---------
|
|
|
|
|
|
|
|
Threading
|
|
:::::::::
|
|
|
|
|
|
Threading
|
|
---------
|
|
|
|
|
|
Spanwing Processes
|
|
------------------
|
|
|
|
|
|
Multiprocessing
|
|
---------------
|
|
|
|
|
|
.. _`PyPy`: http://pypy.org
|
|
.. _`The GIL`: http://wiki.python.org/moin/GlobalInterpreterLock
|
|
.. _`guide`: http://www.dabeaz.com/python/UnderstandingGIL.pdf
|
|
.. _`New GIL`: http://www.dabeaz.com/python/NewGIL.pdf
|
|
.. _`Special care`: http://docs.python.org/c-api/init.html#threads |