How does a robot control system properly shut down? In general it does not stop. Pressing an emergency button might switch to a emergency safety level. However, in a system under development it is often desirable to end an application. That usually means to switch to a specific safety level where the necessary steps for a well controlled stopping of the application takes place. Only after this happened the executor stops running and returns control to the main program, which then stops as well.
The following example shows how this can be accomplished. The code can be found in safetysystem. First of all you have to define a signal handler which handles all kind of signals, among them the SIGINT signal which is sent by pressing Ctrl-C.

#include "MySafetyProperties.hpp>
#include <signal.h>
 
void signalHandler(int signum) {
	SafetySystem::exitHandler();
}
 
int main() {
  signal(SIGHUP, signalHandler);
  signal(SIGINT, signalHandler);
  signal(SIGQUIT, signalHandler);
  signal(SIGKILL, signalHandler);
  signal(SIGTERM, signalHandler);
  signal(SIGPWR, signalHandler);
 
  ...
 
  // Create and initialize safety system
  double period = 1;
  MySafetyProperties ssProperties;
  SafetySystem safetySys(ssProperties, period);
 
  ... 
}

exitFunction = [&](SafetyContext* privateContext) {
  privateContext->triggerEvent(seShutDown);
};

SafetyEvent seShutDown;