[petsc-dev] IS updates breaking some fortran tests

Barry Smith bsmith at mcs.anl.gov
Wed Nov 17 16:26:31 CST 2010

  Remove VecValid() from petsc-dev and your problem goes away


On Nov 17, 2010, at 4:24 PM, Dmitry Karpeev wrote:

> I agree that my changes should have nothing to do with VecValid, which
> is why this is so baffling.
> I've rebuilt the fortran bindings, rebuilt PETSc etc, etc -- to no avail.
> I thought it might be a memory corruption due to an expanded IS
> struct, but valgrind doesn't detect anything.
> This error is the reason I've been sitting on this commit for a while,
> but I figured someone else might figure it
> out faster than I can :-)
> Dmitry.
> On Wed, Nov 17, 2010 at 4:19 PM, Barry Smith <bsmith at mcs.anl.gov> wrote:
>> On Nov 17, 2010, at 4:15 PM, Dmitry Karpeev wrote:
>>> I just pushed an IS update that causes problems in some fortran tests.
>>> I'm not sure exactly what's going on, but a failure occurs, for
>>> example, in src/vec/examples/tests/ex1f
>>> in VecValid.  Looked at with a debugger it reveals that 'flg', a
>>> pointer to boolean that is being passed from Fortran
>>> to C, is wiped out and emerges as NULL on the C side (I assume, upon a
>>> cast; since there is no temporary
>>> in vecvalid_ that holds the result of the "cast", I can't really
>>> examine the intermediate value passed to C).
>>> I've been trying to figure this out for a bit, but have come up with
>>> nothing so far (e.g., valgrind runs on ex1f fine).
>>> I'm sure this will show up in the nightly builds, but I figured I'd
>>> push this change, hoping that someone with a
>>> better knowledge of Fortran bindings will help me figure this out.
>>> Thanks.
>>> Dmitry.
>>  Huh, your changes shouldn't have anything to do with VecValid, nor affect it in any way. Any problem should exist both with or without your changes
>>   BTW: VecValid() is not a legitimate function, should never be used and should be removed from PETSc-dev ASAP. Why it is too dangerous poking around with an unknown pointer.
>>   Barry

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