Message 64654 - Python tracker

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Author	pitrou
Recipients	anthonybaxter, christian.heimes, jafo, janixia, jhylton, loewis, pitrou, tim.peters
Date	2008-03-28.22:45:06
SpamBayes Score	0.0021040312
Marked as misclassified	No
Message-id	<1206744308.79.0.450831305038.issue815646@psf.upfronthosting.co.za>
In-reply-to

Content
Why hadn't I read #595601 in detail, it has an explanation: [quoting Jeremy Hylton] The universal newline code is squirrels the FILE * in a local variable, which is worse. If it happens that another thread closes the file, at best the local points to a closed FILE *. But that memory could get recycled and then there's no way to know what it points to. [/quoting] Even with careful coding, there's a small window between releasing the GIL on our side, and acquiring the FILE-specific lock in the glibc, during which the fclose() function can be invoked and release the FILE just before we invoke another function (e.g. fseek()) on it.

Why hadn't I read #595601 in detail, it has an explanation: 

[quoting Jeremy Hylton]
The universal newline code is squirrels the FILE * in a
local variable, which is worse.  If it happens that
another thread closes the file, at best the local
points to a closed FILE *.  But that memory could get
recycled and then there's no way to know what it points to.
[/quoting]

Even with careful coding, there's a small window between releasing the
GIL on our side, and acquiring the FILE-specific lock in the glibc,
during which the fclose() function can be invoked and release the FILE
just before we invoke another function (e.g. fseek()) on it.

History
Date	User	Action	Args
2008-03-28 22:45:09	pitrou	set	spambayes_score: 0.00210403 -> 0.0021040312 recipients: + pitrou, tim.peters, loewis, jhylton, anthonybaxter, jafo, janixia, christian.heimes
2008-03-28 22:45:08	pitrou	set	spambayes_score: 0.00210403 -> 0.00210403 messageid: <1206744308.79.0.450831305038.issue815646@psf.upfronthosting.co.za>
2008-03-28 22:45:07	pitrou	link	issue815646 messages
2008-03-28 22:45:06	pitrou	create