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Author majid
Date 2005-04-06.01:03:31
SpamBayes Score
Marked as misclassified
Python 2.4.1 now uses os.urandom() to seed the random
number generator. This is mostly an improvement, but
can lead to subtle regression bugs.

os.urandom() will open /dev/urandom on demand, e.g.
when random.Random.seed() is called, and keep it alive
as os._urandomfd.

It is standard programming practice for a daemon
process to close file descriptors it has inherited from
its parent process, and if it closes the file
descriptor corresponding to os._urandomfd, the os
module is blissfully unaware and the next time
os.urandom() is called, it will try to read from a
closed file descriptor (or worse, a new one opened
since), with unpredictable results.

My recommendation would be to make os.urandom() open
/dev/urandom each time and not keep a persistent file
descripto. This will be slightly slower, but more
robust. I am not sure how I feel about a standard
library function steal a file descriptor slot forever,
specially when os.urandom() is probably going to be
called only once in the lifetime of a program, when the
random module is seeded.
Date User Action Args
2007-08-23 14:30:44adminlinkissue1177468 messages
2007-08-23 14:30:44admincreate