# Invoked after a call to `check_signals` if a signal has been raised
	# (should be redefed by subclasses)
	#
	# Should be used by most signals except `sigkill` and `sigstop` since they
	# cannot be caught, blocked or ignored.
	#
	#     class MyReceiver
	#         super SignalHandler
	#
	#         redef fun receive_signal(signal) do print "received safely {signal}"
	#     end
	#
	#     var r = new MyReceiver
	#     r.handle_signal(sigint, true) # will call back when "check_signals" is called
	#     # ...
	#     check_signals # if a signal was received, it will invoke `r.receive_signal`
	fun receive_signal(signal: Int) do end