bug with os.rename in 2.4.1?
nick at craig-wood.com
Tue Apr 28 21:30:02 CEST 2009
t123 <tom.lukes at gmail.com> wrote:
> It's running on solaris 9. Here is some of the code. It's actually
> at the beginning of the job. The files are ftp'd over. The first
> thing that happens is that the files get renamed before any processing
> of the file. And when it fails, it always fails at the first file,
> comm.dat. What I can't understand is why the inconsistent behavior.
> if os.path.exists(paths.xferin_dir+'/COMM.DAT'):
This code is inherently racy... What if two copies of your code
started simultaneously? They might both run the os.path.exists but
only one will succeed in the os.rename.
You could write instead
Which isn't racy. Or if you wanted to be more thorough
except OSError, e:
if e.errno != errno.ENOENT:
The traceback should show the exact problem though.
Nick Craig-Wood <nick at craig-wood.com> -- http://www.craig-wood.com/nick
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