[petsc-dev] GASM

[Dmitry Karpeev]

Pushed: http://petsc.cs.iit.edu/petsc/petsc-dev/rev/76f5543c7e89

On Thu, Mar 29, 2012 at 11:07 AM, Barry Smith <bsmith at mcs.anl.gov> wrote:

>
>  I think Jed is suggesting changing:
>
> PetscErrorCode  KSPDestroy(KSP *ksp)
> {
>  PetscErrorCode ierr;
>
>  PetscFunctionBegin;
>  if (!*ksp) PetscFunctionReturn(0);
>  PetscValidHeaderSpecific((*ksp),KSP_CLASSID,1);
>  if (--((PetscObject)(*ksp))->refct > 0) {*ksp = 0;
> PetscFunctionReturn(0);}
>
>  ierr = KSPReset((*ksp));CHKERRQ(ierr);
>
>
>
> to
>
>
> PetscErrorCode  KSPDestroy(KSP *ksp)
> {
>  PetscErrorCode ierr;
>  PC                         pc = (*ksp)->pc;
>
>  PetscFunctionBegin;
>  if (!*ksp) PetscFunctionReturn(0);
>  PetscValidHeaderSpecific((*ksp),KSP_CLASSID,1);
>  if (--((PetscObject)(*ksp))->refct > 0) {*ksp = 0;
> PetscFunctionReturn(0);}
>
>
>  pc = (*ksp)->pc;
>  (*ksp)->pc = PETSC_NULL;
>  ierr = KSPReset((*ksp));CHKERRQ(ierr);
>  (*ksp)->pc = pc;
>
>
>   Since KSPDestroy() doesn't need to have  PCReset() called. This doesn't
> require any special code for users.
>
>   Barry
>
>
> On Mar 29, 2012, at 10:38 AM, Dmitry Karpeev wrote:
>
> >
> >
> > On Thu, Mar 29, 2012 at 10:13 AM, Jed Brown <jedbrown at mcs.anl.gov>
> wrote:
> > On Thu, Mar 29, 2012 at 08:28, Dmitry Karpeev <karpeev at mcs.anl.gov>
> wrote:
> > Back to the original problem: how shall we prevent a shared pc from
> being gutted by an unprotected PCReset() cascading from a KSPDestroy() on
> one of the containing ksps?  I can factor out
> KSPReset_Private()/PCReset_Private() as indicated before, unless there are
> objections.
> >
> >  What do you think of my suggestion of masking ksp->pc when KSPDestroy
> calls KSPReset? Then KSPReset does not call PCReset if ksp->pc does not
> exist.
> > I guess that works too, but I thought your suggestion applied to
> userland code right before calling KSPDestroy(&ksp)?
> > I suppose that will fix Mark's problem.  Maybe that's the right
> approach: he got himself into this mess by reusing a pc
> > in the inner ksp, he should know how to extricate himself :-)
> >
> > Dmitry.
> >
>
>
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