Is it possible that recent changes make this solution easier? DMKSP/SNES/TS is now a PETSc object. Should we be attaching context-appropriate pointers there so that they can be copied along with this context?<br><br>There's also the last-ditch approach I took to having a SNESShell properly take an implementation-specific fortran pointer, which was to compose it with the object (yeah yeah string lookups)<br>
<br><a href="https://bitbucket.org/petsc/petsc-dev/src/d646bb69827f0fe12031068d40b072920e0212b4/src/snes/impls/shell/ftn-custom/zsnesshellf.c?at=default">https://bitbucket.org/petsc/petsc-dev/src/d646bb69827f0fe12031068d40b072920e0212b4/src/snes/impls/shell/ftn-custom/zsnesshellf.c?at=default</a><br>
<div class="gmail_extra"><br>- Peter<br><br><div class="gmail_quote">On Tue, Dec 4, 2012 at 4:43 PM, Jed Brown <span dir="ltr"><<a href="mailto:jedbrown@mcs.anl.gov" target="_blank">jedbrown@mcs.anl.gov</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div>As usual, anything that is duplicated and not checked by the compiler is broken.<br><br><font face="courier new, monospace">$ grep PetscObjectAllocateFortranPointers src/**/*.c </font></div>
<div><font face="courier new, monospace">src/dm/impls/da/ftn-custom/zda2f.c: PetscObjectAllocateFortranPointers(*da,6);</font></div><div><font face="courier new, monospace">src/dm/impls/da/ftn-custom/zda2f.c: PetscObjectAllocateFortranPointers(*da,6);</font></div>
<div><font face="courier new, monospace">src/dm/impls/shell/ftn-custom/zdmshellf.c: PetscObjectAllocateFortranPointers(*dm,2);</font></div><div><font face="courier new, monospace">src/dm/impls/shell/ftn-custom/zdmshellf.c: PetscObjectAllocateFortranPointers(*dm,2);</font></div>
<div><br></div><div>Note that changing the type does not reset the function pointers, thus having a DMSHELL, calling DMSetType(dm,DMDA), and then setting a DMDA local function will cause memory corruption.</div><div><br>
</div>
<div>I cannot express how much I hate this system. The full-blown solution is that for each type, we register a (global) token which is the index of that function pointer. That doesn't have any false dependencies, but is more "initialize" code.</div>
<div><br></div><div>An alternative, used in the TS and KSP code below, is to have a common enum that lists all the Fortran functions. It's a false header dependency, but not a binary dependency.</div><div><br></div><div>
What should we do? The current state is a disaster.</div><div><br></div><div><font face="courier new, monospace">src/ksp/ksp/impls/gmres/fgmres/ftn-custom/zmodpcff.c: PetscObjectAllocateFortranPointers(*ksp,3);</font></div>
<div><font face="courier new, monospace">src/ksp/ksp/interface/ftn-custom/zitfuncf.c: PetscObjectAllocateFortranPointers(*ksp,FTN_MAX);</font></div><div><font face="courier new, monospace">src/ksp/ksp/interface/ftn-custom/zitfuncf.c: PetscObjectAllocateFortranPointers(*ksp,FTN_MAX);</font></div>
<div><font face="courier new, monospace">src/ksp/pc/impls/mg/ftn-custom/zmgfuncf.c: PetscObjectAllocateFortranPointers(*mat,1);</font></div><div><font face="courier new, monospace">src/ksp/pc/impls/shell/ftn-custom/zshellpcf.c: PetscObjectAllocateFortranPointers(*pc,5);</font></div>
<div><font face="courier new, monospace">src/ksp/pc/impls/shell/ftn-custom/zshellpcf.c: PetscObjectAllocateFortranPointers(*pc,5);</font></div><div><font face="courier new, monospace">src/ksp/pc/impls/shell/ftn-custom/zshellpcf.c: PetscObjectAllocateFortranPointers(*pc,5);</font></div>
<div><font face="courier new, monospace">src/ksp/pc/impls/shell/ftn-custom/zshellpcf.c: PetscObjectAllocateFortranPointers(*pc,5);</font></div><div><font face="courier new, monospace">src/ksp/pc/impls/shell/ftn-custom/zshellpcf.c: PetscObjectAllocateFortranPointers(*pc,5);</font></div>
<div><font face="courier new, monospace">src/mat/impls/mffd/ftn-custom/zmffdf.c: PetscObjectAllocateFortranPointers(*mat,2);</font></div><div><font face="courier new, monospace">src/mat/impls/shell/ftn-custom/zshellf.c: PetscObjectAllocateFortranPointers(*mat,11);</font></div>
<div><font face="courier new, monospace">src/mat/interface/ftn-custom/zmatrixf.c: PetscObjectAllocateFortranPointers(*sp,1);</font></div><div><font face="courier new, monospace">src/snes/interface/ftn-custom/zsnesf.c: PetscObjectAllocateFortranPointers(*snes,14);</font></div>
<div><font face="courier new, monospace">src/snes/interface/ftn-custom/zsnesf.c: PetscObjectAllocateFortranPointers(*snes,14);</font></div><div><font face="courier new, monospace">src/snes/interface/ftn-custom/zsnesf.c: PetscObjectAllocateFortranPointers(*snes,14);</font></div>
<div><font face="courier new, monospace">src/snes/interface/ftn-custom/zsnesf.c: PetscObjectAllocateFortranPointers(*snes,14);</font></div><div><font face="courier new, monospace">src/snes/interface/ftn-custom/zsnesf.c: PetscObjectAllocateFortranPointers(*snes,14);</font></div>
<div><font face="courier new, monospace">src/snes/linesearch/impls/shell/ftn-custom/zlinesearchshellf.c: PetscObjectAllocateFortranPointers(*linesearch,3);</font></div><div><font face="courier new, monospace">src/snes/linesearch/interface/ftn-custom/zlinesearchf.c: PetscObjectAllocateFortranPointers(*linesearch,3);</font></div>
<div><font face="courier new, monospace">src/snes/linesearch/interface/ftn-custom/zlinesearchf.c: PetscObjectAllocateFortranPointers(*linesearch,3);</font></div><div><font face="courier new, monospace">src/sys/draw/utils/ftn-custom/zzoomf.c: PetscObjectAllocateFortranPointers(*draw,1);</font></div>
<div><font face="courier new, monospace">src/ts/interface/ftn-custom/ztsf.c: PetscObjectAllocateFortranPointers(*ts,OUR_COUNT);</font></div><div><font face="courier new, monospace">src/ts/interface/ftn-custom/ztsf.c: PetscObjectAllocateFortranPointers(*ts,OUR_COUNT);</font></div>
<div><font face="courier new, monospace">src/ts/interface/ftn-custom/ztsf.c: PetscObjectAllocateFortranPointers(*ts,OUR_COUNT);</font></div><div><font face="courier new, monospace">src/ts/interface/ftn-custom/ztsf.c: PetscObjectAllocateFortranPointers(*ts,OUR_COUNT);</font></div>
<div><font face="courier new, monospace">src/ts/interface/ftn-custom/ztsf.c: PetscObjectAllocateFortranPointers(*ts,OUR_COUNT);</font></div><div><font face="courier new, monospace">src/ts/interface/ftn-custom/ztsf.c: PetscObjectAllocateFortranPointers(*ts,OUR_COUNT);</font></div>
<div><font face="courier new, monospace">src/ts/interface/ftn-custom/ztsf.c: PetscObjectAllocateFortranPointers(*ts,OUR_COUNT);</font></div>
</blockquote></div><br></div>