how to use multi-thread & multi-process in python
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北京迅达云成科技有限公司 www.speedycloud.cn 2015 年 9 月 北京WELCOME
How to Use Multi-thread & Multi-process in Python
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Why using multi-thread?
Productivity
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Multi-thread Multi-process
Code Review
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You Got Me!
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What is GIL ？
In C-python, the global interpreter lock, or GIL, is a mutex that prevents multiple native threads from executing Python byte-codes at once. This lock is necessary mainly because C-Python’s memory management is not thread-safe.(However, since the GIL exists, other features have grown to depend on the guarantees that it enforces.)
GIL will serialize threads and stop the concurrence of threads.
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Multi-thread test
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Python multi-thread, no use at all?
NO!
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The Good News…
I/O Intensive ：
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IO Intensive Running Sequence
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Unfortunately…CPU Intensive Task: Multi-thread’s
productivity even worse than single thread
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How to deal with it?
First:Ctypes
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Second:multiprocessing
Extra ：multiprocessing.dummy
How to deal with it?
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Been there, done that…Join()
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file discripter
In Linux, all operations on all devices and/or files are done via file descriptor.
Been there, done that…
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北京迅达云成科技有限公司 www.speedycloud.cn
Thanks!
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