memory safe subscription callback

[ewak]

Manage the lifetime of the bondStatusCB member function by wrapping it in a lambda that captures a weak_ptr (via public inheritance of std::enable_shared_from_this)

NOTE:
This is a draft to show how it could be done.

It solves a use after free that is being experienced using intraprocess communication in nav2 ros-navigation/navigation2#4691 .

Also being discussed as a bug in rclcpp - ros2/rclcpp#2678 (comment)

Something like createSafeSubscriptionMemFuncCallback could make its way into the rclcpp namespace.

[SteveMacenski]

Note that beyond the linting problems that the job points out, there's an actual set of test failures in test_callbacks_cpp which probably point to a bug in the implementation / a test that needs a minor update:

02:07:59 1: Test command: /usr/bin/python3 "-u" "/opt/ros/rolling/share/ament_cmake_test/cmake/run_test.py" "/tmp/ws/test_results/test_bond/test_callbacks_cpp.gtest.xml" "--package-name" "test_bond" "--output-file" "/tmp/ws/build_isolated/test_bond/ament_cmake_gtest/test_callbacks_cpp.txt" "--command" "/tmp/ws/build_isolated/test_bond/test_callbacks_cpp" "--gtest_output=xml:/tmp/ws/test_results/test_bond/test_callbacks_cpp.gtest.xml"
02:07:59 1: Working Directory: /tmp/ws/build_isolated/test_bond
02:07:59 1: Test timeout computed to be: 60
02:07:59 1: -- run_test.py: invoking following command in '/tmp/ws/build_isolated/test_bond':
02:07:59 1:  - /tmp/ws/build_isolated/test_bond/test_callbacks_cpp --gtest_output=xml:/tmp/ws/test_results/test_bond/test_callbacks_cpp.gtest.xml
02:07:59 1: Running main() from /opt/ros/rolling/src/gtest_vendor/src/gtest_main.cc
02:07:59 1: [==========] Running 2 tests from 1 test suite.
02:07:59 1: [----------] Global test environment set-up.
02:07:59 1: [----------] 2 tests from TestCallbacksCpp
02:07:59 1: [ RUN      ] TestCallbacksCpp.dieInLifeCallback
02:07:59 1: unknown file: Failure
02:07:59 1: C++ exception with description "bad_weak_ptr" thrown in the test body.
02:07:59 1: 
02:07:59 1: [  FAILED  ] TestCallbacksCpp.dieInLifeCallback (14 ms)
02:07:59 1: [ RUN      ] TestCallbacksCpp.remoteNeverConnects
02:07:59 1: unknown file: Failure
02:07:59 1: C++ exception with description "bad_weak_ptr" thrown in the test body.
02:07:59 1: 
02:07:59 1: [  FAILED  ] TestCallbacksCpp.remoteNeverConnects (5 ms)
02:07:59 1: [----------] 2 tests from TestCallbacksCpp (20 ms total)
02:07:59 1: 
02:07:59 1: [----------] Global test environment tear-down
02:07:59 1: [==========] 2 tests from 1 test suite ran. (27 ms total)
02:07:59 1: [  PASSED  ] 0 tests.
02:07:59 1: [  FAILED  ] 2 tests, listed below:
02:07:59 1: [  FAILED  ] TestCallbacksCpp.dieInLifeCallback
02:07:59 1: [  FAILED  ] TestCallbacksCpp.remoteNeverConnects
02:07:59 1: 
02:07:59 1:  2 FAILED TESTS
02:07:59 1: -- run_test.py: return code 1
02:07:59 1: -- run_test.py: inject classname prefix into gtest result file '/tmp/ws/test_results/test_bond/test_callbacks_cpp.gtest.xml'
02:07:59 1: -- run_test.py: verify result file '/tmp/ws/test_results/test_bond/test_callbacks_cpp.gtest.xml'
02:07:59 1/7 Test #1: test_callbacks_cpp ...............***Failed    0.21 sec

[ewak]

@SteveMacenski fixed the lint and test. This change requires the Bond to be created as a shared_ptr.

[ewak]

@SteveMacenski This is another use_intraprocess_comms fix. i.e the Bond Status publisher for use_intraprocess_comms should use a unique msg and check for subscribers.

This allows nav2_system_tests to pass.

NOTE: without this change the following test was failure was very reproducible for me.

colcon test --packages-select nav2_system_tests --event-handlers=console_direct+ --ctest-args -R test_speed_filter_global

ref: ros-navigation/navigation2#4691