I think it is too useful to give up. It seems crazy that there would not be OS calls like
bool validAddress(void *add); Matt On Tue, Mar 30, 2010 at 11:55 AM, William Gropp <wgropp at illinois.edu> wrote: > As long as you have a flat address space, this trick works. The problem is > (was) for systems with memory segments; in that case, &realarray[-1] might > not be valid. > > Bill > > On Mar 30, 2010, at 12:30 PM, Barry Smith wrote: > > > What do the PETSc developers think of this? Is it "otherwise, the > behavior is undefined, *even if the pointer is not dereferenced*."? > > Whenever we work with global indices like in FormFunctionLocal() we do > this. > > Is PETSc wrong to ever do this? Is there any other way to allow users > to work with global indices in a simple way? Do we need to strip out all the > FormFunctionLocals() from PETSc? Not the end of the world but it provides > such a nice simple interface for simple problems it seems a pity to toss it. > > Thanks > > Barry > > > William Gropp > Deputy Director for Research > Institute for Advanced Computing Applications and Technologies > Paul and Cynthia Saylor Professor of Computer Science > University of Illinois Urbana-Champaign > > > > > -- 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 -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20100330/7994f02d/attachment.html>
