[Python-Dev] Asking for reversion

[Neil Schemenauer]

I wrote:
> Could we somehow mark these APIs as experimental in 3.8?

It seems the change "e5ef45b8f519a9be9965590e1a0a587ff584c180" the
one we are discussing.  It adds two new files:

  Lib/multiprocessing/shared_memory.py
  Modules/_multiprocessing/posixshmem.c

It doesn't introduce new C APIs.  So, only
multiprocessing.shared_memory seems public.  I see we have PEP 411
that should cover this case:

  https://www.python.org/dev/peps/pep-0411/

The setup.py code could be more defensive.  Maybe only build on
platforms that have supported word sizes etc?  For 3.8, could it be
activated by uncommenting a line in Modules/Setup, rather than by
setup.py?

What happens in shared_memory if the _posixshmem module is not
available?  On Windows it seems like an import error is raised.
Otherwise, _PosixSharedMemory becomes 'object'.  Does that mean the
API still works but you lose the zero-copy speed?

Regards,

  Neil