sm_coretest_signal_key_1

Core test for signal-connection cleanup of state-scoped subscribers. It checks that when a client behavior or a state subscribes to a signal with this, the connection is finalized when the subscriber is destroyed, so that later emissions never reach a dead object.

Design

• ClTickSource (in OrTick) owns a free-running CpRos2Timer at 5 Hz. The component lives for the whole state machine, so its onTimerTick signal keeps firing after any state has exited.
• CbMixinFirstSubscriber is deliberately declared : public ISmaccUpdatable, public SmaccClientBehavior, with the non-SMACC base first. That layout places the ISmaccClientBehavior subobject away from the start of the object, so the pointer the behavior subscribes with and the base pointer the orthogonal disposes it with are different addresses. The behavior subscribes to the tick in onEntry and logs [CbMixinFirstSubscriber] TICK n.
• StA runs the behavior for 1 s and also subscribes to the same tick itself, with this, from its own onEntry, logging [StA] STATE TICK n. Boost.Statechart destroys the state object right after exit().
• StRest (1 s) has no subscriber of either kind. The machine cycles StA -> StRest -> StA every 2 s.

Pass criteria

• No TICK or STATE TICK line is logged while StRest is active. Any such line is a callback delivered into a destroyed behavior or state.
• Each StA lifetime logs about 5 ticks for the behavior and about 5 for the state, reported at exit (onExit, ticks= and Exiting. state ticks=).
• Under AddressSanitizer: no heap-use-after-free, no SEGV.

The failure signature, if the cleanup regresses, is a heap-use-after-free inside the bound signal lambda under CpRos2Timer::timerCallback, with the memory freed either by the orthogonal’s shared_ptr release (behavior case) or by boost::statechart::detail::deallocate (state case). In a plain build the state case segfaults on the first tick after the first StA exit.

Running

Plain:

ros2 launch sm_coretest_signal_key_1 sm_coretest_signal_key_1.launch.py

The launch file tees the node output to /tmp/sm_coretest_signal_key_1_latest.log.

For sanitizer runs, build in a separate build and install base with the sanitizer flags and run the node binary directly, without a launch prefix (a stdbuf prefix preloads a library ahead of the sanitizer runtime and ASan refuses to start):

install_asan/sm_coretest_signal_key_1/lib/sm_coretest_signal_key_1/sm_coretest_signal_key_1_node --ros-args --log-level INFO

Twelve seconds, six cycles, is enough to see every pass criterion.

Note

StA reaches the timer component through the state-level requiresComponent, once by type and once by name (the empty default name), and logs an error if the two disagree. Until the forwarders were fixed the state had to go through getOrthogonal<OrTick>()->getClients().front()->getComponent<CpRos2Timer>().

StA also asks for ClAbsent, a client type no orthogonal holds, through the state-level requiresClient on every entry. The core answers with a null pointer and one ERROR line naming the state ([sm_coretest_signal_key_1::StA] Client of type ... not found); that line is expected, six times in a 12 s run. The state name in it must be intact: the core used to take c_str() of a temporary for it, which read freed memory (a heap-use-after-free under ASan).