Extension modules, Threading, and the GIL

["Martin v. Löwis"]

Bengt Richter wrote:
>>David is right that it does not matter for this issue how a thread is 
>>created: Python can deal with threads created through C API just as fine 
>>as with "Python threads"; Python threads are created through the very 
>>same C API.
> 
> Well, I meant if C stuff didn't use Python's C API to create a thread and
> all the good python stuff that the thread or threading modules will do for you.
> I meant C calling something like win32 API

And I meant the very same thing. There is absolutely nothing wrong in 
creating a thread thread CreateThread, and then using a Python 
interpreter in it.


> and doing something totally off to the side as far as Python was concerned.
> IWT the result of the above would be different from a C API call to e.g.,
> 
>     thread.start_new_thread(function, args[, kwargs]) 

It would not be different at all. start_new_thread uses CreateThread 
under the hoods.

> Well, what would happen if a win32 thread that had not been started with
> thread.start_new_thread or C-API equivalent, nevertheless attempted to
> acquire the lock? 

It would work just fine. The thread would either acquire it immediately, 
or block until the thread that currently holds it releases it.

Regards,
Martin