The valgrind software is used to check for memory issues in gml4gtk,
To fix all valgrind messages is the fastest way to prevent bugs and
fix hidden bugs.
Also the valgrind callgrind program can generate callgraph info
which can be converted to dot graph data using gpof2dot at https://github.com/jrfonseca/gprof2dot
The valgrind messages with gml4gtk come from the external GTK+ libs
and not gml4gtk and maybe some day they can also these issues fixed
These dot graph files can be used with gml4gtk and it looks like