C-extension not threadable?

[Dave Cole]

>>>>> "Martin" == Martin v Loewis <martin at v.loewis.de> writes:

Martin> Dave Cole <djc at object-craft.com.au> writes:
>> I think that it is preferable to keep the exception and propagate
>> it back from the callback through the API to the thread which
>> called the API.  I am not sure why discarding the exception would
>> be a good idea.

Martin> That assumes that the call originated from Python. If some
Martin> library has created the thread (e.g. in response to an
Martin> incoming network connection which was accepted by the
Martin> library), there won't be anybody to propagate the exception
Martin> to.

The assumption is not an assumption in this case because the original
question was about this very situation.

Marcus> The thread is started like this:
Marcus> 
Marcus> T=threading.Thread(group=None,target=ExtModule.CFunction,name=None,
Marcus>                            args=(a,b,c,self.callback))
Marcus>         T.start()


>> IMO, from the point of view of the extension module user it should
>> not be visible that there was some non-Python code between the
>> Python code where the exception was raised and the Python code
>> which called the module API.

Martin> Again, assuming there is Python code on both sides, and also
Martin> assuming it is possible to pass something through from one end
Martin> to the other. *If* that is possible, you can just as well pass
Martin> the thread state through. If you cannot pass the thread-state
Martin> through, due to the design of the library you are wrapping,
Martin> tough luck: chances are low that you can pass the exception
Martin> back.

Agreed, but (I thought) we were talking about the situation where
Python created the threads.

- Dave

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