Memory leak: meta objects not destroyed

[martiniil]

Using the ClassLoader (version 0.4.1) via pluginlib as recommended, we could detect some memory leaks.
My guess is that metaobjects are not destroyed after they have been inserted into the "graveyard". Or did I miss something here?

Could be related: ros/pluginlib#126

See the log below. It would be nice to get another opinion.

Excerpt of log.txt:

Direct leak of 160 byte(s) in 1 object(s) allocated from:
    #0 0x7f82ba691458 in operator new(unsigned long) (/usr/lib/x86_64-linux-gnu/libasan.so.4+0xe0458)
    #1 0x7f82a3c28f4e in void class_loader::impl::registerPlugin<prbt_manipulator::IKFastKinematicsPlugin, kinematics::KinematicsBase>(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) /opt/ros/melodic/include/class_loader/class_loader_core.hpp:205
    #2 0x7f82a3b12d20 in ProxyExec0 /home/rosuser/catkin_ws/src/pilz_robots/prbt_ikfast_manipulator_plugin/src/prbt_manipulator_ikfast_moveit_plugin.cpp:1401
    #3 0x7f82a3b130f3 in __static_initialization_and_destruction_0 /home/rosuser/catkin_ws/src/pilz_robots/prbt_ikfast_manipulator_plugin/src/prbt_manipulator_ikfast_moveit_plugin.cpp:1401
    #4 0x7f82a3b1310e in _GLOBAL__sub_I_prbt_manipulator_ikfast_moveit_plugin.cpp /home/rosuser/catkin_ws/src/pilz_robots/prbt_ikfast_manipulator_plugin/src/prbt_manipulator_ikfast_moveit_plugin.cpp:1401
    #5 0x7f82bb57c732  (/lib64/ld-linux-x86-64.so.2+0x10732)

Indirect leak of 79 byte(s) in 1 object(s) allocated from:
    #0 0x7f82ba691458 in operator new(unsigned long) (/usr/lib/x86_64-linux-gnu/libasan.so.4+0xe0458)
    #1 0x7f82b8795bc6 in std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_assign(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) (/usr/lib/x86_64-linux-gnu/libstdc++.so.6+0x124bc6)

Indirect leak of 68 byte(s) in 2 object(s) allocated from:
    #0 0x7f82ba691458 in operator new(unsigned long) (/usr/lib/x86_64-linux-gnu/libasan.so.4+0xe0458)
    #1 0x7f82b9e6db6c  (/opt/ros/melodic/lib/libclass_loader.so+0x17b6c)

Indirect leak of 31 byte(s) in 1 object(s) allocated from:
    #0 0x7f82ba691458 in operator new(unsigned long) (/usr/lib/x86_64-linux-gnu/libasan.so.4+0xe0458)
    #1 0x7f82ba36c3e2 in void std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >::_M_construct<char const*>(char const*, char const*, std::forward_iterator_tag) /usr/include/c++/7/bits/basic_string.tcc:219
    #2 0x7f82a3c3f1e7 in class_loader::impl::AbstractMetaObject<kinematics::KinematicsBase>::AbstractMetaObject(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) /opt/ros/melodic/include/class_loader/meta_object.hpp:155
    #3 0x7f82a3c32f64 in class_loader::impl::MetaObject<prbt_manipulator::IKFastKinematicsPlugin, kinematics::KinematicsBase>::MetaObject(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) /opt/ros/melodic/include/class_loader/meta_object.hpp:186
    #4 0x7f82a3c28f6a in void class_loader::impl::registerPlugin<prbt_manipulator::IKFastKinematicsPlugin, kinematics::KinematicsBase>(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) /opt/ros/melodic/include/class_loader/class_loader_core.hpp:205
    #5 0x7f82a3b12d20 in ProxyExec0 /home/rosuser/catkin_ws/src/pilz_robots/prbt_ikfast_manipulator_plugin/src/prbt_manipulator_ikfast_moveit_plugin.cpp:1401
    #6 0x7f82a3b130f3 in __static_initialization_and_destruction_0 /home/rosuser/catkin_ws/src/pilz_robots/prbt_ikfast_manipulator_plugin/src/prbt_manipulator_ikfast_moveit_plugin.cpp:1401
    #7 0x7f82a3b1310e in _GLOBAL__sub_I_prbt_manipulator_ikfast_moveit_plugin.cpp /home/rosuser/catkin_ws/src/pilz_robots/prbt_ikfast_manipulator_plugin/src/prbt_manipulator_ikfast_moveit_plugin.cpp:1401
    #8 0x7f82bb57c732  (/lib64/ld-linux-x86-64.so.2+0x10732)

Indirect leak of 8 byte(s) in 1 object(s) allocated from:
    #0 0x7f82ba691458 in operator new(unsigned long) (/usr/lib/x86_64-linux-gnu/libasan.so.4+0xe0458)
    #1 0x7f82b9e6e383 in void std::vector<class_loader::ClassLoader*, std::allocator<class_loader::ClassLoader*> >::_M_realloc_insert<class_loader::ClassLoader* const&>(__gnu_cxx::__normal_iterator<class_loader::ClassLoader**, std::vector<class_loader::ClassLoader*, std::allocator<class_loader::ClassLoader*> > >, class_loader::ClassLoader* const&) (/opt/ros/melodic/lib/libclass_loader.so+0x18383)

SUMMARY: AddressSanitizer: 346 byte(s) leaked in 6 allocation(s).

[agutenkunst]

I created a minimal demo: https://github.com/agutenkunst/leak_demo_pkg

[tylerjw]

I second I've experienced this too. I get a flood of these when using moveit building with address sanitizer. I tried looking through the code to see if I can understand what I should be doing to fix this but I can't figure it out.

[v4hn]

According to these comments the whole problem boils down to the basic decision whether the library should

• support opening and closing libraries with plugins multiple times
  or
• leak memory because there are no means to destroy the global factories correctly once the plugin libraries are dlclose()d.

The library went with the former option and we are stuck with unfreeable memory as a result.