[Python-Dev] Final PEP 311 run (original) (raw)

Mark Hammond mhammond@skippinet.com.au
Thu, 17 Apr 2003 11:58:01 +1000

Hi all, I'd like to get PEP311 in for the Python 2.3b1 - http://www.python.org/peps/pep-0311.html (or even if I miss, very soon after!)

There appears to be no issues with the technical aspects of the PEP (please correct me now if I am wrong). The only issue is the name of the API.

To save re-reading the PEP just to understand the names, I will summarize here (see the PEP for the full version):

There are 2 new functions, called as a pair. The first function sets up the Python thread state, along with the GIL, so that the current thread can safely call the Python API. The function makes no assumptions about the current state of the GIL etc - it works out the current state, and does the "right thing". The second function is the reverse of the first, to indicate that the thread has finished with the thread state for the time being.

The PEP calls these functions PyAutoThreadState_Ensure() and PyAutoThreadState_Release()

Reasons for the names in the PEP: "Auto" reflects that the current thread-state need not be known (whereas the other APIs do). "Ensure()" reflects that nothing may actually be created - all we are doing is "ensuring" we have the resources, creating only if necessary. On the down-side - "Auto" will look strange in the future when this is the standard way of managing the lock. "ThreadState" does not reflect that the function does more than manage the PyThreadState - it also manages the locks (which while an implementation detail, are currently discrete)

Other Proposals: Just: PyGIL_Ensure(), PyGIL_Release(): shorter to type, conveys the meaning. David Abrahams: Prefers SubjectVerbObject, so would prefer "PyEnsureGIL" - but likes PyAcquireInterpreter() and PyReleaseInterpreter() best. Dropping "Auto" from the PEP gives PyThreadState_Ensure() and PyThreadState_Release().

I admit to liking "PyAcquireInterpreter()" best, but it does not match the existing API structure. For the sake of typing, I would be happy to go with Just's PyGIL_Ensure(), but maybe PyInterpreter_Ensure() is a good compromise.

Other opinions or pronouncements welcome :)

Mark.