On 14Jun2014 01:40, SABARWAL, SHAL <ss3...@att.com> wrote:
Appreciate any help in resolving/understanding following error.
Very occasionally get following error. The error occurs once every 20 - 30
days. OS HP-UX 11.11
############### ERROR LISTNG #############################
sem_init: Device busy
[...]
once_lock = _allocate_lock()
thread.error: can't allocate lock
[...]
This looks like (erroneous) reuse of a previously allocated anonymous
semaphore. Have a read of HP-UX's sem_init(2) manual page:
http://condor.depaul.edu/dmumaugh/readings/handouts/CSC343/pthreads_man%20pages/semaphore.txt
This will be the underlying OS interface used to make a Python lock. It takes
as an argument a pointer to a piece of memory to represent the semaphore.
That page says that the error code EBUSY ("Device busy") is issued if:
There are threads currently blocked on the semaphore or there are
outstanding locks held on the semaphore.
I would take this to represent a bug in the python code that manages the
semaphores supporting the Lock objects. It looks like the code reuses a
previous sem_t C object while it is still in use. Since this happens very
rarely for you I would guess this is a race condition not detected in testing.
I guess my first question would be: what release of Python are you running?
Have you considered getting the latest source code for Python ( version 2 or 3
according to what your code is using) and building that? It may be that this
issue has been fixed in a later release of Python than the one currently
installed on your HP-UX box.
Cheers,
Cameron Simpson <c...@zip.com.au>
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