[petsc-dev] calling petsc from a mex file

[Munson, Todd]

Its in tmunson/tao-pounders-matlab-interface

Most of the code is commented out or otherwise inactive.  There is a hacked
command in src/tao/leastsquares/examples/matlab that I use to compile the
mex file.

To test, you should be able to start matlab and say "taopounders(); exit".

Todd.

> On May 8, 2018, at 2:21 PM, Smith, Barry F. <bsmith at mcs.anl.gov> wrote:
> 
> 
>  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
>