[Tim]
I'd like to intensify the problem, though:
Good! I was just taking small steps to get to the same endpoint.
you're in a thread and you want to call a Python API function safely. Period. You don't know anything else. You don't even know whether Python has been initialized yet, let alone whether there's already a thread state, and/or an interpreter state, sitting around available for you to use.
Agreed 100%. In some ways, I believe this is just the conclusion from my 2 points taken together if we can ignore the current world order. I split them to try and differentiate the requirements from the current API, but if we progress to Tim's description, my points become: 1) Becomes exactly as Tim stated. 2.1) Stays the same - release the GIL. 2.2) Goes away - if (1) requires no knowledge of Python's state, there is no need for extensions to take special action just to enable this.
I'd also like to postulate that proposed solutions can rely on a new Python C API supplying a portable spelling of thread-local storage. We can implement that easily on pthreads and Windows boxes, it seems to me to cut to the heart of several problems, and I'm willing to say that Python threading doesn't work anymore on other boxes until platform wizards volunteer code to implement this API there too.
This sounds good to me. After you have done the Win98 version, I volunteer to port it to Win2k <wink>. I believe we have a reasonable starting point. Our PEP could have: * All the usual PEP fluff <wink> * Define the goal, basically as stated by Tim. * Define a new C API specifically for this purpose, probably as an "optional extension" to the existing thread state APIs. * Define a TLS interface that all ports must implement *iff* this new API is to be available. This sounds reasonable to me unless we can see a number of other uses for TLS - in which case the TLS interface would probably get its own PEP, with this PEP relying on it. However, I don't see too much need for TLS - once we have our hands on a Python thread-state, we have a thread-specific dictionary available today, and a TLS dictionary from inside your Python code is trivial. From what I can see, we just need platform TLS to get hold of our thread-state, from which point we can (and do) manage our own thread specific data. How does this sound? Mark.