[Python-Dev] Pymalloc and backward compatibility (original) (raw)

Neil Schemenauer nas@python.ca
Thu, 4 Apr 2002 07:20:50 -0800

Moore, Paul wrote:

I've been watching the pymalloc discussions going on recently, and I'm concerned that there may be some fairly major compatibility changes coming.

We are trying to avoid that.

The code has survived essentially unchanged through [Python 1.4] to Python 2.2, and still works fine.

This is a great test case. Can you provide a URL to the code?

It seems to me that there are two options open for me:

1. The Python API from 1.4 is still guaranteed to work unchanged (even given the liberties mentioned above). In that case, do nothing. 2. There are changes required. In that case, make them, protected by python API checks (annoying ifdef fun).

As long as you don't use free() to deallocate objects then you are safe. Python 1.4 has PyMem_DEL. You can use a macro like this:

#if PY_VERSION_HEX < 0x01060000
#define PyObject_New PyObject_NEW
#define PyObject_Del PyMem_DEL
#endif

and use PyObject_New and PyObject_Del to manage object memory.

Neil