Debugging and profiling

Debugging

This section gives some tips about debugging code_aster.

Note

waf_debug install turns on ASTER_DEBUG_CXX flag that prints some debugging informations. Additional details about objects live-cycle can be printed by defining environment variables CXXFLAGS=-DASTER_DEBUG_CXX_OBJECTS or CXXFLAGS=-DASTER_DEBUG_CXX_LOW_LEVEL, or both CXXFLAGS='-DASTER_DEBUG_CXX_OBJECTS -DASTER_DEBUG_CXX_LOW_LEVEL''. Please ask a guru before adding new blocks under these flags!

Detailed informations about the command syntax checker can be printed using the debug level of the logger. Use --debug option or set DEBUG=1 environment variable.

Todo

It will give an example of debugging the C++/Fortran objects of a sequential or a parallel build.

Another part will give some informations to debug the Python part.

Helper functions

• debugPrint(): This method is available on all DataStructure objects. It prints the content of all its Jeveux objects.

• use_count(): This method is a wrapping to std::shared_ptr< T > use_count() member. It is available for only some DataStructure.

Build of elements failed

In the case that the installation (waf_debug install) failed during building the elements catalog, the output ends with something like:

+ build the elements catalog elem.1 using installed aster (from cata_ele.ojb)
stdout: ...
<sometimes the message is not clear enough>
...
stderr: ...
To run manually, use:
...
<command line to reproduce the error>

First, you can restart in verbose mode (and with one process to have a synced output):

./waf_debug install -v -j 1

If it is not sufficient, try to reproduce the error in a new terminal (adjust build and installation directories if needed):

cd /tmp
ulimit -c unlimited
. ${HOME}/dev/codeaster/install/debug/share/aster/profile.sh
python3 ${HOME}/dev/codeaster/src/build/mpidebug/debug/catalo/fort.1 --memory=4096

It may create a core file. In this case, try:

gdb $(which python3) core
(gdb) where
...

If it does not give interesting informations, try to import each modules of code_aster as done in code_aster/__init__.py:

python3
>>> import aster
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: .../dev/codeaster/install/mpi/lib64/aster/libbibfor.so: undefined symbol: scotchfdgraphcorderinit_

This is an example of error caused by a missing external library.

Another frequent error:

python3
>>> import aster
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: .../dev/codeaster/install/debug/lib64/aster/libbibcxx.so: undefined symbol: _Z7nmdocr_PKcS0_Pcjj

Here, nmdocr is a Fortran subroutine, called from C++. Its prototype must be enclosed by extern "C" { ... }.

Profiling

The well known tool gprof is a very good and simple choice to profile an executable but it does not work to profile a shared library. And code_aster is a Python module built as a shared library.

Note

Profiling code_aster using gperftools has been tested but the analysis of the results was difficult.

More tools have to be evaluated.