[petsc-users] check for NULL pointer in VecCreateGhost

[Matthew Knepley]

On Mon, Feb 20, 2012 at 6:30 PM, Mohammad Mirzadeh <mirzadeh at gmail.com>wrote:

> Matt, I'm just trying to understand what is going on and why the things do
> what they do -- I'm not asking for anything in particular :). I just
> thought that the situation for VecCreateGhost and AOXXXXToYYYY are somewhat
> similar here and was surprised to see one crashes on NULL while the other
> one does not.
>
> I have included a check on the pointer and size for AO calls and just
> wanted to check if I need the same thing with VecCreateGhost if there is
> such an internal check.
>

I have no problem making that change. It is pushed to petsc-dev.

   Matt


> Mohammad
>
>
> On Mon, Feb 20, 2012 at 4:10 PM, Matthew Knepley <knepley at gmail.com>wrote:
>
>> On Mon, Feb 20, 2012 at 5:58 PM, Mohammad Mirzadeh <mirzadeh at gmail.com>wrote:
>>
>>> Just if wondering what the actual code is, here's the bit causing the
>>> trouble:
>>>
>>> AOApplicationToPetsc(ao, ghostNodes.size(), (int*)ghostNodes);
>>> VecCreateGhost(comm, localNodes.size(), PETSC_DECIDE, ghostNodes.size(),
>>> (int*)ghostNodes, &v);
>>> AOPetscToApplication(ao, ghostNodes.size(), (int*)ghostNodes);
>>>
>>> when the code is in serial, ghostNodes.size() = 0 and (int*)ghostNodes =
>>> NULL.
>>>
>>
>> So you are asking us to give up checking for NULL if the size is 0?
>>
>>    Matt
>>
>>
>>> On Mon, Feb 20, 2012 at 3:54 PM, Mohammad Mirzadeh <mirzadeh at gmail.com>wrote:
>>>
>>>> Sure, Jed. My bad. Here's the whole message when the code is run in
>>>> _serial_:
>>>>
>>>> [0]PETSC ERROR: --------------------- Error Message
>>>> ------------------------------------
>>>> [0]PETSC ERROR: Invalid pointer!
>>>> [0]PETSC ERROR: Null Pointer: Parameter # 3!
>>>> [0]PETSC ERROR:
>>>> ------------------------------------------------------------------------
>>>> [0]PETSC ERROR: Petsc Release Version 3.2.0, Patch 6, Wed Jan 11
>>>> 09:28:45 CST 2012
>>>> [0]PETSC ERROR: See docs/changes/index.html for recent updates.
>>>> [0]PETSC ERROR: See docs/faq.html for hints about trouble shooting.
>>>> [0]PETSC ERROR: See docs/index.html for manual pages.
>>>> [0]PETSC ERROR:
>>>> ------------------------------------------------------------------------
>>>> [0]PETSC ERROR: ./petsc on a arch-linu named mohammad-laptop by
>>>> mohammad Mon Feb 20 15:52:25 2012
>>>> [0]PETSC ERROR: Libraries linked from
>>>> /home/mohammad/soft/petsc-3.2-p6/arch-linux2-cxx-debug/lib
>>>> [0]PETSC ERROR: Configure run at Thu Feb 16 02:16:40 2012
>>>> [0]PETSC ERROR: Configure options --with-cc=gcc --with-cxx=g++
>>>> --with-fc=gfortran --with-clanguage=cxx --download-f-blas-lapack=1
>>>> --download-mpich=1 --download-hypre=1 --download-ml=1
>>>> --with-parmetis-include=/home/mohammad/soft/parmetis/include
>>>> --with-parmetis-lib="-L/home/mohammad/soft/parmetis/lib -lparmetis -lmetis"
>>>> --download-superlu_dist=1
>>>> [0]PETSC ERROR:
>>>> ------------------------------------------------------------------------
>>>> [0]PETSC ERROR: AOApplicationToPetsc() line 249 in
>>>> /home/mohammad/soft/petsc-3.2-p6/src/dm/ao/interface/ao.c
>>>> [0]PETSC ERROR: --------------------- Error Message
>>>> ------------------------------------
>>>> [0]PETSC ERROR: Invalid pointer!
>>>> [0]PETSC ERROR: Null Pointer: Parameter # 3!
>>>> [0]PETSC ERROR:
>>>> ------------------------------------------------------------------------
>>>> [0]PETSC ERROR: Petsc Release Version 3.2.0, Patch 6, Wed Jan 11
>>>> 09:28:45 CST 2012
>>>> [0]PETSC ERROR: See docs/changes/index.html for recent updates.
>>>> [0]PETSC ERROR: See docs/faq.html for hints about trouble shooting.
>>>> [0]PETSC ERROR: See docs/index.html for manual pages.
>>>> [0]PETSC ERROR:
>>>> ------------------------------------------------------------------------
>>>> [0]PETSC ERROR: ./petsc on a arch-linu named mohammad-laptop by
>>>> mohammad Mon Feb 20 15:52:25 2012
>>>> [0]PETSC ERROR: Libraries linked from
>>>> /home/mohammad/soft/petsc-3.2-p6/arch-linux2-cxx-debug/lib
>>>> [0]PETSC ERROR: Configure run at Thu Feb 16 02:16:40 2012
>>>> [0]PETSC ERROR: Configure options --with-cc=gcc --with-cxx=g++
>>>> --with-fc=gfortran --with-clanguage=cxx --download-f-blas-lapack=1
>>>> --download-mpich=1 --download-hypre=1 --download-ml=1
>>>> --with-parmetis-include=/home/mohammad/soft/parmetis/include
>>>> --with-parmetis-lib="-L/home/mohammad/soft/parmetis/lib -lparmetis -lmetis"
>>>> --download-superlu_dist=1
>>>> [0]PETSC ERROR:
>>>> ------------------------------------------------------------------------
>>>> [0]PETSC ERROR: AOPetscToApplication() line 210 in
>>>> /home/mohammad/soft/petsc-3.2-p6/src/dm/ao/interface/ao.c
>>>>
>>>>
>>>> It seems to complain about the 3rd parameter of AOApplicationToPetsc()
>>>> and AOPetscToApplication(). VecCreateGhost, on the other hand, is fine.
>>>>
>>>> On Mon, Feb 20, 2012 at 3:47 PM, Jed Brown <jedbrown at mcs.anl.gov>wrote:
>>>>
>>>>> On Mon, Feb 20, 2012 at 17:25, Mohammad Mirzadeh <mirzadeh at gmail.com>wrote:
>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> Is there an internal check to see if the 'ghost' pointer in
>>>>>> VecCreateGhost() is NULL ? This can happen, for example, if the code is run
>>>>>> in serial and the there are no ghost points (hence n_ghost = 0 and ghost =
>>>>>> NULL(implementation dependent of course) ). AOXXXXToYYYY functions seem to
>>>>>> crash if the corresponding pointer is NULL.
>>>>>>
>>>>>
>>>>> Always send the whole error message.
>>>>>
>>>>
>>>>
>>>
>>
>>
>> --
>> What most experimenters take for granted before they begin their
>> experiments is infinitely more interesting than any results to which their
>> experiments lead.
>> -- Norbert Wiener
>>
>
>


-- 
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which their
experiments lead.
-- Norbert Wiener
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