[Python-Dev] are CObjects inherently unsafe?

Michael Hudson mwh at python.net
Fri Dec 5 10:12:45 EST 2003

Guido van Rossum <guido at python.org> writes:

>> > Indeed, CObjects seem fundamentally dangerous to me, unless
>> > the modules which create and use them are extremely careful
>> > to make sure they can tell whether they've got the right
>> > kind of CObject.
>> Well, the right *CObject* -- it's CObject identity that matters.
> I seem to recall that the CObject design contains a feature to avoid
> using the wrong CObject, but it's not used by any of the CObject
> implementations in the standard library, and the CObject docs don't
> describe how it's meant to use (they were clearly reverse-engineered
> from the code).
> And the docs should be updated to explain the description better
> (currently at one point the description is called "extra callback data
> for the destructor function" which seems a rather odd feature).

It had occurred to me that you could use this field for this purpose,
but it hadn't occurred to me that this might have been the *intent* of
this field.

Why a void* then?  That's particularly unassertive.  char* would be
better, surely...


  I also fondly recall Paris because that's where I learned to
  debug Zetalisp while drunk.                          -- Olin Shivers

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