[petsc-dev] Suggestions for MatProductCreate()

[Lisandro Dalcin]

* Please consider fixing MatProductCreate(A,B,C,&D) to take ownership (that
is, increase reference count) of the A,B, and the (optional) C matrices
provided as arguments. Otherwise it is way easy to get into the dangling
pointer trap.

* A thing also missing in the new API is a way to "cleanup" the A,B,C
references, something MatProductReset(D) to get rid of (deallocates) the
internal "product" context, thus removing  from D the references to A,B,C.
This would be useful if you just want to compute JUST the symbolic product,
I'm using that in some code to compute the nonzero pattern of A^2.

* It should be also considered to provide backward compatibility
PETSC_DEPRECATED calls to the previous MatMatMultSymbolic()
and MatMatMultNumeric(). It looks like it would be trivial to do, though I
may be getting it wrong because I have not looked at all the details.

Regards,

-- 
Lisandro Dalcin
============
Research Scientist
Extreme Computing Research Center (ECRC)
King Abdullah University of Science and Technology (KAUST)
http://ecrc.kaust.edu.sa/
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20200323/ff43a4cd/attachment.html>