Threaded import hang in cPickle.dumps
Zac Burns
cPickle.dumps has an import which is causing my application to hang.
(figured out by overriding builtin.__import__ with a print and seeing
that this is the last line of code being run. I'm running
cPickle.dumps in a thread, which leads me to believe that the first
restriction here is the cause:
http://docs.python.org/library/threading.html#importing-in-threaded-code
What can I do about this?
--
Zachary Burns
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Zindagi Games
Zac Burns
Benjamin Peterson
> What can I do about this?
Not run it in a thread.
Zac Burns
> http://mail.python.org/mailman/listinfo/python-list
>
Isn't requesting that pickle not be used in a thread a bit of a tall
order? Just thinking through the common use cases - database access,
server request threads, file IO... pickle is commonly used in threads.
Furthermore, the pickle documentation makes no mention of not being threadsafe.
Antoine Pitrou
>
> cPickle.dumps has an import which is causing my application to hang.
> (figured out by overriding builtin.__import__ with a print and seeing
> that this is the last line of code being run. I'm running cPickle.dumps
> in a thread, which leads me to believe that the first restriction here
> is the cause:
> http://docs.python.org/library/threading.html#importing-in-threaded-code
>
Please report a bug at http://bugs.python.org
Better even if you can provide a small snippet of code which reproduces
the problem reliably.
Regards
Antoine.
Christian Heimes
> Using python 2.6
>
> cPickle.dumps has an import which is causing my application to hang.
> (figured out by overriding builtin.__import__ with a print and seeing
> that this is the last line of code being run. I'm running
> cPickle.dumps in a thread, which leads me to believe that the first
> restriction here is the cause:
> http://docs.python.org/library/threading.html#importing-in-threaded-code
>
> What can I do about this?
You can do two things to stop the import lock from dead locking.
* Never ever start a thread as a side effect of an import. This means
you must not start a thread in the body of a module. As I explained in
numerous other messages a well designed application imports all its
modules first. After all modules have been imported the components are
initialized and the threads are started.
* Import all modules that are referred inside your pickled data before
you unpickle.
Christian