[issue5502] io-c: TextIOWrapper is faster than BufferedReader but not protected by a lock

[STINNER Victor]

New submission from STINNER Victor <victor.stinner at haypocalc.com>:

TextIOWrapper.readline() is much faster (eg. 72 ms vs 95 ms) than 
BufferedReader.readline(). It's because BufferedReader always acquires 
the file lock, whereas TextIOWrapper only acquires the file lock when 
the buffer is empty.

I would like a BufferedReader.readline() as fast as 
TextIOWrapper.readline(), or faster!

Why BufferedReader's attributes are protected by a lock whereas 
TextIOWrapper's attributes are not?

Does it mean that TextIOWrapper may crash if two threads calls 
readline() (or different methods) at the "same time"?

How does Python 2.x and 3.0 fix this issue?

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components: Library (Lib)
messages: 83724
nosy: haypo, pitrou
severity: normal
status: open
title: io-c: TextIOWrapper is faster than BufferedReader but not protected by a lock
versions: Python 3.1

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue5502>
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