destroyed nodes can cause Executor to crash #272
Description
User error alert! This is probably because I'm still learning C++11 🤕 but I suspect I might not be the only person who tries to do this:
rclcpp::executors::SingleThreadedExecutor executor;
executor.add_node(std::make_shared<MyNodeSubclass>());
executor.spin();
which results in this:
terminate called after throwing an instance of 'std::system_error'
what(): Invalid argument
with this backtrace:
Thread 1 "minimal_talker" received signal SIGABRT, Aborted.
0x00007ffff6647428 in __GI_raise (sig=sig@entry=6)
at ../sysdeps/unix/sysv/linux/raise.c:54
54 ../sysdeps/unix/sysv/linux/raise.c: No such file or directory.
(gdb) bt
#0 0x00007ffff6647428 in __GI_raise (sig=sig@entry=6)
at ../sysdeps/unix/sysv/linux/raise.c:54
#1 0x00007ffff664902a in __GI_abort () at abort.c:89
#2 0x00007ffff6c8084d in __gnu_cxx::__verbose_terminate_handler() ()
from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#3 0x00007ffff6c7e6b6 in ?? () from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#4 0x00007ffff6c7e701 in std::terminate() ()
from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#5 0x00007ffff6c7e919 in __cxa_throw ()
from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#6 0x00007ffff6ca77fe in std::__throw_system_error(int) ()
from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#7 0x0000000000417d03 in std::mutex::lock() ()
#8 0x0000000000418a36 in std::lock_guard<std::mutex>::lock_guard(std::mutex&)
()
#9 0x00007ffff79a4ea8 in GuardCondition::attachCondition(std::mutex*, std::condition_variable*) () from /home/mquigley/ros2/install/lib/librmw_fastrtps_cpp.so
#10 0x00007ffff799d7bc in rmw_wait ()
from /home/mquigley/ros2/install/lib/librmw_fastrtps_cpp.so
#11 0x00007ffff7767026 in rcl_wait ()
from /home/mquigley/ros2/install/lib/librcl.so
#12 0x00007ffff7439b3e in rclcpp::executor::Executor::wait_for_work(std::chrono::duration<long, std::ratio<1l, 1000000000l> >) ()
from /home/mquigley/ros2/install/lib/librclcpp.so
#13 0x00007ffff743ad61 in rclcpp::executor::Executor::get_next_executable(std::chrono::duration<long, std::ratio<1l, 1000000000l> >) ()
from /home/mquigley/ros2/install/lib/librclcpp.so
#14 0x00007ffff7441f45 in rclcpp::executors::single_threaded_executor::SingleThreadedExecutor::spin() () from /home/mquigley/ros2/install/lib/librclcpp.so
#15 0x0000000000417927 in main ()
I'm not sure what the right answer is. If it's possible to somehow generate a warning and say something like "hey there! I hope you're having a gr8 day. You should probably hold a shared_ptr to that instance on your stack." But that might be hard to generate (actually I have no idea how one could generate that).