On Wed, Jan 6, 2010 at 7:32 PM, Benjamin Peterson <benja...@python.org> wrote: > 2010/1/6 John Arbash Meinel <john.arbash.mei...@gmail.com>: > > AFAIK, the only things that don't require the GIL are macro functions, > > like PyString_AS_STRING or PyTuple_SET_ITEM. PyErr_SetString, for > > example, will be increfing and setting the exception state, so certainly > > needs the GIL to be held. > > As a general rule, I would say, no Py* macros are safe without the gil > either (the exception being Py_END_ALLOW_THREADS), since they mutate > Python objects which must be protected.
That's keeping it on the safe side, since there are some macros like PyString_AS_STRING() that are also safe, *if* you are owning at least one reference to the string object. At the same time, "no Py* macros" is not quite strong enough, since if you called PyString_AS_STRING() before releasing the GIL but you don't own a reference to the string object, the string might be deallocated behind your back by another thread. A better rule would be "you may access the memory buffer in a PyString or PyUnicode object with the GIL released as long as you own a reference to the string object." Everything else is out of bounds (or not worth the bother). -- --Guido van Rossum (python.org/~guido) _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
