osdir.com


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Python-Dev] C API changes


On 11/23/18 5:15 AM, Armin Rigo wrote:
> Also FWIW, my own 2 cents on the topic of changing the C API: let's
> entirely drop ``PyObject *`` and instead use more opaque
> handles---like a ``PyHandle`` that is defined as a pointer-sized C
> type but is not actually directly a pointer.  The main difference this
> would make is that the user of the API cannot dereference anything
> from the opaque handle, nor directly compare handles with each other
> to learn about object identity.  They would work exactly like Windows
> handles or POSIX file descriptors.

Why would this be better than simply returning the pointer? Sure, it 
prevents ever dereferencing the pointer and messing with the object, it 
is true.? So naughty people would be prevented from messing with the 
object directly instead of using the API as they should.? But my 
understanding is that the implementation would be slightly 
slower--there'd be all that looking up objects based on handles, and 
managing the handle namespace too.? I'm not convinced the nice-to-have 
of "you can't dereference the pointer anymore" is worth this runtime 
overhead.

Or maybe you have something pretty cheap in mind, e.g. "handle = pointer 
^ 49"?? Or even "handle = pointer ^ (random odd number picked at 
startup)" to punish the extra-naughty?



//arry/
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/python-dev/attachments/20181126/23654aa6/attachment.html>