[petsc-dev] Integrating PFLOTRAN, PETSC & SAMRAI

[Boyce Griffith]

On 6/6/11 5:23 PM, Barry Smith wrote:
>
>    Jed,
>
>       Though VecRestoreArray() does increase the Vector state,  we also have our base Vec class methods (and MatMult and friends) ALSO increase the state on appropriate Vec arguments (so for built-in Vec classes like VECSEQ the state is increased twice) . So for all of those routines there is no reason for an alternative Vec class to manage the state itself. Thus is it not completely unreasonable for Boyce (and people in similar situations) to ask that they never need to manage the state themselves.  They do need to because of SNESComputeFunction().

I don't mind managing state per se --- it just seems confusing to have 
to know/remember that FormFunction() needs an state increase but, e.g., 
MatVecMult doesn't.

E.g., looking at the wrapper code a few years down the road, I will 
probably have forgotten the details of this email thread, and I might be 
tempted to remove PetscObjectStateIncrease from FormFunction because I 
don't see it used in any other parts of the wrapper, which may or may 
not be a mistake.

I guess that my point is that right now, there does not seem to be a 
good way to find out where one needs to call PetscObjectStateIncrease() 
other than asking petsc-dev at mcs.anl.gov.  :-)

-- Boyce