So who wrote the PetscOpFList() code and who will refactor it? Is this a
high priority or just something to be listed on that website and then ignored
for years?
Barry
On Jan 15, 2013, at 2:14 PM, Jed Brown <jedbrown at mcs.anl.gov> wrote:
> On Tue, Jan 15, 2013 at 1:50 PM, Barry Smith <bsmith at mcs.anl.gov> wrote:
>
> Do we really want mallocs for EVERY single multiple-dispatch function call
> in PETSc? I suggest not having MatQueryOp() but calling directly
> PetscOpFListFind() (with the MatOpFList argument) and changing
> PetscOpFListAdd/Find() to use variable args directly.
>
> Finally do we really want string comparisons at all here? Or do we want
> XXXRegister() (for example, MatRegister()) to compute an integer type id to
> go with each char *type_name and do the search off the integer type id
> instead of strings? Thus making PetscOpFListFind() super light weight?
>
> static struct {
> PetscMultiDispatch ptap;
> ...
> } MatMultiDispatch;
>
> I would have PetscMultiDispatchRegister("MatPtAP",2,&MatMultiDispatch.ptap),
> then
>
> PetscMultiDispatchFind(MatMultiDispatch.ptap,(PetscObject)A,(PetscObject)P,&ptapfunc);
>
> I think passing PetscObject is natural here, in which case using obj->type_id
> instead of obj->type_name can be done later. But on that front, yes, I think
> making integers for all registered type_names would be good. Among other
> things, it would make the PetscObjectTypeCompares fast, although I think
> those places should eventually be refactored.
>
>
> Barry
>
>
> PetscErrorCode MatQueryOp(MPI_Comm comm, PetscVoidFunction* function, const
> char op[], PetscInt numArgs, ...)
> {
> PetscErrorCode ierr;
> va_list ap;
> PetscInt i;
> const char *argType;
> char **argTypes = PETSC_NULL;
>
> PetscFunctionBegin;
> va_start(ap,numArgs);
> if (numArgs) {
> ierr = PetscMalloc(sizeof(char*)*numArgs, &argTypes);CHKERRQ(ierr);
> }
> for (i = 0; i < numArgs; ++i) {
> argType = va_arg(ap,const char*);
> ierr = PetscStrallocpy(argType, argTypes+i);CHKERRQ(ierr);
> }
> va_end(ap);
> ierr = PetscOpFListFind(comm, MatOpList, function, op, numArgs,
> argTypes);CHKERRQ(ierr);
> for (i = 0; i < numArgs; ++i) {
> ierr = PetscFree(argTypes[i]);CHKERRQ(ierr);
> }
> ierr = PetscFree(argTypes);CHKERRQ(ierr);
> PetscFunctionReturn(0);
> }
>
>
