transition_vtol_fixed_wing example never ready to arm

[hamishwillee]

This example is never ready to arm. Running it sometimes gets a segmentation fault.

$ ./transition_vtol_fixed_wing udp://:14540
Waiting to discover system...
[03:18:46|Info ] New device on: 127.0.0.1:14557 (udp_connection.cpp:208)
[03:18:46|Debug] New: System ID: 1 Comp ID: 1 (dronecore_impl.cpp:286)
[03:18:46|Debug] Component Autopilot added. (mavlink_system.cpp:330)
[03:18:46|Debug] MAVLink: info: data link #1 lost (mavlink_system.cpp:267)
[03:18:46|Debug] MAVLink: info: data link #1 regained (mavlink_system.cpp:267)
[03:18:46|Debug] Found 1 component(s). (mavlink_system.cpp:462)
[03:18:46|Debug] Discovered 4294967298 (mavlink_system.cpp:464)
Discovered system with UUID: 4294967298
[03:18:46|Debug] We got an ack: 520 (mavlink_commands.cpp:140)
[03:18:48|Debug] We got an ack: 511 (mavlink_commands.cpp:140)
Vehicle not ready to arm
Segmentation fault (core dumped)

I changed the arm test code such that it retries the health check:

// Check if vehicle is ready to arm
while (telemetry->health_all_ok() != true) {
std::cout << ERROR_CONSOLE_TEXT << "Vehicle not ready to arm" << NORMAL_CONSOLE_TEXT << std::endl;
sleep_for(std::chrono::seconds(1));
}

In this case I got it ready to arm after 1 second. But then it fails with landed state unknown.

Vehicle not ready to arm
Altitude: 0.044 m
Arming...
Arming failed:Command denied, landed state is unknown

BUT, if I change nothing and just run the takeoff_and_land example it will takeoff and land. No problems with arming at all.

[julianoes]

@hamishwillee thanks for reporting. I can reproduce this:

valgrind ./transition_vtol_fixed_wing
==11685== Memcheck, a memory error detector
==11685== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==11685== Using Valgrind-3.13.0 and LibVEX; rerun with -h for copyright info
==11685== Command: ./transition_vtol_fixed_wing
==11685== 
Waiting to discover system...
[09:44:40|Info ] New device on: 127.0.0.1:14557 (udp_connection.cpp:208)
[09:44:40|Debug] New: System ID: 1 Comp ID: 1 (dronecore_impl.cpp:286)
[09:44:40|Debug] Component Autopilot added. (mavlink_system.cpp:338)
[09:44:41|Debug] MAVLink: info: data link #0 lost (mavlink_system.cpp:275)
[09:44:41|Debug] MAVLink: info: data link #0 regained (mavlink_system.cpp:275)
[09:44:41|Debug] Found 1 component(s). (mavlink_system.cpp:470)
[09:44:41|Debug] Discovered 4294967298 (mavlink_system.cpp:472)
Discovered system with UUID: 4294967298
Vehicle not ready to arm
==11685== Thread 2:
==11685== Invalid read of size 2
==11685==    at 0x4F0BD7D: dronecore::MAVLinkSystem::process_mavlink_message(__mavlink_message const&) (mavlink_system.cpp:130)
==11685==    by 0x4F095D7: dronecore::System::process_mavlink_message(__mavlink_message const&) (system.cpp:58)
==11685==    by 0x4F18AA0: dronecore::DroneCoreImpl::receive_message(__mavlink_message const&) (dronecore_impl.cpp:82)
==11685==    by 0x4F071AA: dronecore::Connection::receive_message(__mavlink_message const&) (connection.cpp:42)
==11685==    by 0x4F433CA: dronecore::UdpConnection::receive(dronecore::UdpConnection*) (udp_connection.cpp:227)
==11685==    by 0x4F43760: void std::__invoke_impl<void, void (*)(dronecore::UdpConnection*), dronecore::UdpConnection*>(std::__invoke_other, void (*&&)(dronecore::UdpConnection*), dronecore::UdpConnection*&&) (invoke.h:60)
==11685==    by 0x4F434A2: std::__invoke_result<void (*)(dronecore::UdpConnection*), dronecore::UdpConnection*>::type std::__invoke<void (*)(dronecore::UdpConnection*), dronecore::UdpConnection*>(void (*&&)(dronecore::UdpConnection*), dronecore::UdpConnection*&&) (invoke.h:95)
==11685==    by 0x4F43A0E: decltype (__invoke((_S_declval<0ul>)(), (_S_declval<1ul>)())) std::thread::_Invoker<std::tuple<void (*)(dronecore::UdpConnection*), dronecore::UdpConnection*> >::_M_invoke<0ul, 1ul>(std::_Index_tuple<0ul, 1ul>) (thread:234)
==11685==    by 0x4F439C9: std::thread::_Invoker<std::tuple<void (*)(dronecore::UdpConnection*), dronecore::UdpConnection*> >::operator()() (thread:243)
==11685==    by 0x4F439AD: std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (*)(dronecore::UdpConnection*), dronecore::UdpConnection*> > >::_M_run() (thread:186)
==11685==    by 0x569C512: ??? (in /usr/lib64/libstdc++.so.6.0.25)
==11685==    by 0x62E1563: start_thread (in /usr/lib64/libpthread-2.27.so)
==11685==  Address 0xadf1530 is 0 bytes after a block of size 768 alloc'd
==11685==    at 0x4C2E226: operator new(unsigned long) (vg_replace_malloc.c:334)
==11685==    by 0x4F15BD8: __gnu_cxx::new_allocator<dronecore::MAVLinkSystem::MAVLinkHandlerTableEntry>::allocate(unsigned long, void const*) (new_allocator.h:111)
==11685==    by 0x4F14CB9: std::allocator_traits<std::allocator<dronecore::MAVLinkSystem::MAVLinkHandlerTableEntry> >::allocate(std::allocator<dronecore::MAVLinkSystem::MAVLinkHandlerTableEntry>&, unsigned long) (alloc_traits.h:436)
==11685==    by 0x4F1359D: std::_Vector_base<dronecore::MAVLinkSystem::MAVLinkHandlerTableEntry, std::allocator<dronecore::MAVLinkSystem::MAVLinkHandlerTableEntry> >::_M_allocate(unsigned long) (stl_vector.h:296)
==11685==    by 0x4F11A89: void std::vector<dronecore::MAVLinkSystem::MAVLinkHandlerTableEntry, std::allocator<dronecore::MAVLinkSystem::MAVLinkHandlerTableEntry> >::_M_realloc_insert<dronecore::MAVLinkSystem::MAVLinkHandlerTableEntry const&>(__gnu_cxx::__normal_iterator<dronecore::MAVLinkSystem::MAVLinkHandlerTableEntry*, std::vector<dronecore::MAVLinkSystem::MAVLinkHandlerTableEntry, std::allocator<dronecore::MAVLinkSystem::MAVLinkHandlerTableEntry> > >, dronecore::MAVLinkSystem::MAVLinkHandlerTableEntry const&) (vector.tcc:427)
==11685==    by 0x4F0FBCF: std::vector<dronecore::MAVLinkSystem::MAVLinkHandlerTableEntry, std::allocator<dronecore::MAVLinkSystem::MAVLinkHandlerTableEntry> >::push_back(dronecore::MAVLinkSystem::MAVLinkHandlerTableEntry const&) (stl_vector.h:1085)
==11685==    by 0x4F0BB38: dronecore::MAVLinkSystem::register_mavlink_message_handler(unsigned short, std::function<void (__mavlink_message const&)>, void const*) (mavlink_system.cpp:81)
==11685==    by 0x53CB6C1: dronecore::TelemetryImpl::init() (telemetry_impl.cpp:69)
==11685==    by 0x4F0E3BE: dronecore::MAVLinkSystem::register_plugin(dronecore::PluginImplBase*) (mavlink_system.cpp:856)
==11685==    by 0x53CB3D0: dronecore::TelemetryImpl::TelemetryImpl(dronecore::System&) (telemetry_impl.cpp:53)
==11685==    by 0x53C8C6E: dronecore::Telemetry::Telemetry(dronecore::System&) (telemetry.cpp:11)
==11685==    by 0x409B9E: void __gnu_cxx::new_allocator<dronecore::Telemetry>::construct<dronecore::Telemetry, dronecore::System&>(dronecore::Telemetry*, dronecore::System&) (in /home/julianoes/src/DroneCore/example/transition_vtol_fixed_wing/build/transition_vtol_fixed_wing)
==11685== 
==11685== Conditional jump or move depends on uninitialised value(s)
==11685==    at 0x4F0BDA8: dronecore::MAVLinkSystem::process_mavlink_message(__mavlink_message const&) (mavlink_system.cpp:130)
==11685==    by 0x4F095D7: dronecore::System::process_mavlink_message(__mavlink_message const&) (system.cpp:58)
==11685==    by 0x4F18AA0: dronecore::DroneCoreImpl::receive_message(__mavlink_message const&) (dronecore_impl.cpp:82)
==11685==    by 0x4F071AA: dronecore::Connection::receive_message(__mavlink_message const&) (connection.cpp:42)
==11685==    by 0x4F433CA: dronecore::UdpConnection::receive(dronecore::UdpConnection*) (udp_connection.cpp:227)
==11685==    by 0x4F43760: void std::__invoke_impl<void, void (*)(dronecore::UdpConnection*), dronecore::UdpConnection*>(std::__invoke_other, void (*&&)(dronecore::UdpConnection*), dronecore::UdpConnection*&&) (invoke.h:60)
==11685==    by 0x4F434A2: std::__invoke_result<void (*)(dronecore::UdpConnection*), dronecore::UdpConnection*>::type std::__invoke<void (*)(dronecore::UdpConnection*), dronecore::UdpConnection*>(void (*&&)(dronecore::UdpConnection*), dronecore::UdpConnection*&&) (invoke.h:95)
==11685==    by 0x4F43A0E: decltype (__invoke((_S_declval<0ul>)(), (_S_declval<1ul>)())) std::thread::_Invoker<std::tuple<void (*)(dronecore::UdpConnection*), dronecore::UdpConnection*> >::_M_invoke<0ul, 1ul>(std::_Index_tuple<0ul, 1ul>) (thread:234)
==11685==    by 0x4F439C9: std::thread::_Invoker<std::tuple<void (*)(dronecore::UdpConnection*), dronecore::UdpConnection*> >::operator()() (thread:243)
==11685==    by 0x4F439AD: std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (*)(dronecore::UdpConnection*), dronecore::UdpConnection*> > >::_M_run() (thread:186)
==11685==    by 0x569C512: ??? (in /usr/lib64/libstdc++.so.6.0.25)
==11685==    by 0x62E1563: start_thread (in /usr/lib64/libpthread-2.27.so)
==11685== 
==11685== 
==11685== Process terminating with default action of signal 11 (SIGSEGV): dumping core
==11685==  Bad permissions for mapped region at address 0xB1D8020
==11685==    at 0x4F0BD7D: dronecore::MAVLinkSystem::process_mavlink_message(__mavlink_message const&) (mavlink_system.cpp:130)
==11685==    by 0x4F095D7: dronecore::System::process_mavlink_message(__mavlink_message const&) (system.cpp:58)
==11685==    by 0x4F18AA0: dronecore::DroneCoreImpl::receive_message(__mavlink_message const&) (dronecore_impl.cpp:82)
==11685==    by 0x4F071AA: dronecore::Connection::receive_message(__mavlink_message const&) (connection.cpp:42)
==11685==    by 0x4F433CA: dronecore::UdpConnection::receive(dronecore::UdpConnection*) (udp_connection.cpp:227)
==11685==    by 0x4F43760: void std::__invoke_impl<void, void (*)(dronecore::UdpConnection*), dronecore::UdpConnection*>(std::__invoke_other, void (*&&)(dronecore::UdpConnection*), dronecore::UdpConnection*&&) (invoke.h:60)
==11685==    by 0x4F434A2: std::__invoke_result<void (*)(dronecore::UdpConnection*), dronecore::UdpConnection*>::type std::__invoke<void (*)(dronecore::UdpConnection*), dronecore::UdpConnection*>(void (*&&)(dronecore::UdpConnection*), dronecore::UdpConnection*&&) (invoke.h:95)
==11685==    by 0x4F43A0E: decltype (__invoke((_S_declval<0ul>)(), (_S_declval<1ul>)())) std::thread::_Invoker<std::tuple<void (*)(dronecore::UdpConnection*), dronecore::UdpConnection*> >::_M_invoke<0ul, 1ul>(std::_Index_tuple<0ul, 1ul>) (thread:234)
==11685==    by 0x4F439C9: std::thread::_Invoker<std::tuple<void (*)(dronecore::UdpConnection*), dronecore::UdpConnection*> >::operator()() (thread:243)
==11685==    by 0x4F439AD: std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (*)(dronecore::UdpConnection*), dronecore::UdpConnection*> > >::_M_run() (thread:186)
==11685==    by 0x569C512: ??? (in /usr/lib64/libstdc++.so.6.0.25)
==11685==    by 0x62E1563: start_thread (in /usr/lib64/libpthread-2.27.so)
==11685== 
==11685== HEAP SUMMARY:
==11685==     in use at exit: 7,456 bytes in 46 blocks
==11685==   total heap usage: 205 allocs, 159 frees, 99,964 bytes allocated
==11685== 
==11685== LEAK SUMMARY:
==11685==    definitely lost: 0 bytes in 0 blocks
==11685==    indirectly lost: 0 bytes in 0 blocks
==11685==      possibly lost: 1,680 bytes in 5 blocks
==11685==    still reachable: 5,776 bytes in 41 blocks
==11685==         suppressed: 0 bytes in 0 blocks
==11685== Rerun with --leak-check=full to see details of leaked memory
==11685== 
==11685== For counts of detected and suppressed errors, rerun with: -v
==11685== Use --track-origins=yes to see where uninitialised values come from
==11685== ERROR SUMMARY: 85216 errors from 2 contexts (suppressed: 0 from 0)
[1]    11685 segmentation fault (core dumped)  valgrind ./transition_vtol_fixed_wing