[petsc-dev] calling petsc from a mex file

[Smith, Barry F.]

  Push the branch that does this or send me the code and I'll debug it. I now have some vague memory about this behavior.

    Barry


> On May 8, 2018, at 1:53 PM, Munson, Todd <tmunson at mcs.anl.gov> wrote:
> 
> 
> 
>> On May 8, 2018, at 1:02 PM, Smith, Barry F. <bsmith at mcs.anl.gov> wrote:
>> 
>> 
>> 
>>> On May 8, 2018, at 12:30 PM, Munson, Todd <tmunson at mcs.anl.gov> wrote:
>>> 
>>> 
>>> Hi,
>>> 
>>> I wonder if anyone has experience calling petsc from matlab using mex.  I have the 
>>> simplest possible mexFunction that just calls PetscInitialize() and 
>>> PetscFinalize().  That part seems to work fine, but when I exit 
>>> from matlab I get a segmentation violation and a petsc error
>>> message.
>> 
>>  What are all the error messages? Cut and paste. I've done this in the past but not for years.
> 
> Below is the matlab session and error message.  I do note that if I issue PetscFinalize() and 
> that command completes, the Petsc signal handlers remain installed/active.  If I do a
> PetscPopSignalHandler() immediately after PetscInitialize(), I do not get the error
> message, but a "Segmentation fault: 11" output at the end.
> 
> Because petsc is being loaded as a dynamic library, are there possibly uninitialized global
> variables or state?
> 
> Thanks, Todd.
> 
> [0]PETSC ERROR: ------------------------------------------------------------------------
> [0]PETSC ERROR: Caught signal number 11 SEGV: Segmentation Violation, probably memory access out of range
> [0]PETSC ERROR: Try option -start_in_debugger or -on_error_attach_debugger
> [0]PETSC ERROR: or see http://www.mcs.anl.gov/petsc/documentation/faq.html#valgrind
> [0]PETSC ERROR: or try http://valgrind.org on GNU/linux and Apple Mac OS X to find memory corruption errors
> [0]PETSC ERROR: likely location of problem given in stack below
> [0]PETSC ERROR: ---------------------  Stack Frames ------------------------------------
> [0]PETSC ERROR: Note: The EXACT line numbers in the stack are not available,
> [0]PETSC ERROR:       INSTEAD the line number of the start of the function
> [0]PETSC ERROR:       is given.
> [0]PETSC ERROR: --------------------- Error Message --------------------------------------------------------------
> [0]PETSC ERROR: Signal received
> [0]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html for trouble shooting.
> [0]PETSC ERROR: Petsc Development GIT revision: v3.9.1-409-gf553c6556e  GIT Date: 2018-05-07 17:17:17 -0500
> [0]PETSC ERROR: Unknown Name on a arch-darwin-c-debug named eduroam062-089.wl.anl-external.org by tmunson Tue May  8 12:04:45 2018
> [0]PETSC ERROR: Configure options --download-mpich CC=/usr/bin/clang CXX=/usr/bin/clang++ FC=/opt/local/bin/gfortran
> [0]PETSC ERROR: #1 User provided function() line 0 in  unknown file
> application called MPI_Abort(MPI_COMM_WORLD, 59) - process 0
> [unset]: write_line error; fd=-1 buf=:cmd=abort exitcode=59
> :
> system msg for write_line failure : Bad file descriptor