#include <stdio.h>
/*
+ This guard prevents errors by the C compiler when the Nit code imports this
+ module but do not use handle_signal. When it is _not_ used, the C type
+ SignalHandler and C function SignalHandler_receive_signal are not generated.
+ Which does not please the C compiler. This guard ensure that we compile this
+ code only if the type SignalHandler has been defined.
+
+ This is a HACK, FIXME by:
+ * Adding the macro to the FFI spec, or
+ * Attach the callbacks to this code block (or the module itself)
+ * Avoid using Nit types and callbacks or use them only in the C implementation
+ of Nit method.
+ */
+ #ifdef NIT_TYPE_SignalHandler
+
+ /*
Structure to manage each possible signals
are used in an array of 32 maximum signals.
This array is global to the software.
}
}
}
+
+ #endif
`}
# Receives the callback from system when a given signal arise
interface SignalHandler
- # Called on any signal received
- fun receive_signal(signal: Int) `{
- `}
-
- # Called on any unsafe signal received
- fun receive_signal_unsafe(signal: Int) `{
- `}
+ # 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
+
+ # Called immediatly on receiving an unsafe signal (should be redefed by subclasses)
+ #
+ # Should be used for `sigkill` and `sigstop` since they cannot be caught,
+ # blocked or ignored.
+ #
+ # You should consider this methods as being fragile. It should be implemented in C
+ # and you should not do too much callbacks to Nit.
+ #
+ # class MyReceiver
+ # super SignalHandler
+ #
+ # redef fun receive_signal_unsafe(signal) do print "received unsafely {signal}"
+ # end
+ #
+ # var r = new MyReceiver
+ # r.handle_signal(sigsegv, false) # `r.receive_signal_unsafe` will be invoked on sigsegv
+ fun receive_signal_unsafe(signal: Int) do end
# Set the receiver as the handler of the signal
- # If safely, receiver will be called when check_signals in invoked
- # otherwise the receiver is invoked when the signal is raised, it may
- # crash the Nit system but is unavoidable for unstoppable signals
+ #
+ # If `safely`, receiver will be called when `check_signals` in invoked
+ # otherwise the receiver is invoked when the signal is raised, it may
+ # crash the Nit system but is unavoidable for unstoppable signals.
fun handle_signal(signal: Int, safely: Bool) import
receive_signal `{
SignalHandler last_handler;