[Python-Dev] PEP 298, final (?) version
Guido van Rossum
Thu, 01 Aug 2002 11:47:25 -0400
> > void PyObject_ReleaseFixedBuffer(PyObject *obj);
> Would it be useful to allow bf_releasefixedbuffer to return an int
> indicating an exception? For instance, it could raise an exception if the
> extension errantly releases more times than it has acquired (a negative
> lock count). Just a thought.
OTOH, it means that the caller would have to check for errors. It may
make more sense to make this a fatal error, since it's purely the
(or at least *a*) caller's fault.
> > Python strings, unicode strings, mmap objects, and array objects
> > would expose the fixed buffer interface.
> > mmap and array objects would actually enter a locked state while
> > the buffer is active, this is not needed for strings and unicode
> > objects. Resizing locked array objects is not allowed and will
> > raise an exception. Whether closing a locked mmap object is an
> > error or will only be deferred until the lock count reaches zero
> > is an implementation detail.
> The mmap object is a good candidate for this, but I'm a little worried
> about adding it to array. I'm not saying it shouldn't be done, but I can
> imagine a surprized user who:
> - has an existing application using the array module
> - starts making use of a new extension that uses the fixed/locked
> buffer interface
> - gets an exception in code that never raised that exception before
Hm. As long as it's not too hard to point out the cause (using the
new extension) I don't think this would be a problem.
--Guido van Rossum (home page: http://www.python.org/~guido/)