Author vstinner
Recipients christian.heimes, hynek, tarek, vstinner
Date 2013-08-16.15:30:57
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Message-id <1376667057.94.0.579949604711.issue18756@psf.upfronthosting.co.za>
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> I have seen complains from e.g. Tarek that os.urandom() fails under high load: https://twitter.com/tarek_ziade/status/362281268215418880

dev_urandom_python() should handle ENFILE and ENOENT differently to raise a different exception. Or it should always call PyErr_SetFromErrno(PyExc_OSError); ?

Can tarek tell us more about its usecases: is he directly calling os.urandom() or does he use the random module? How many threads?

> How about os.urandom() uses a persistent file descriptor?

os.urandom() is called at Python startup to generate a "secret key" for random hash. If the file descriptor is never closed, the next file descriptor will be 4 instead of the expect 3.

Always keeping an internal file descriptor open may have unexpected effects like leaking a file descriptor to a child process... (see the PEP 446, not implemented yet).

I'm ok to keep a fd open if the user controls the lifetime of the object (lifetime of the fd). For example, I expect that rng = SystemRandom() opens /dev/urandom when the object is created, and closes it when the object is destroyed.
History
Date User Action Args
2013-08-16 15:30:57vstinnersetrecipients: + vstinner, christian.heimes, tarek, hynek
2013-08-16 15:30:57vstinnersetmessageid: <1376667057.94.0.579949604711.issue18756@psf.upfronthosting.co.za>
2013-08-16 15:30:57vstinnerlinkissue18756 messages
2013-08-16 15:30:57vstinnercreate