void _bridge_signal_handler_for(int signal_number,
signal_handler_t old_handler) {
// There are five cases interesting here:
// 1) The user has no handler set. Then we decide to exit (and destroy the
// bridge) by calling exit().
// 2) The user has a handler set and ignores the signal. Then we ignore it too
// and everything can go on normally.
// 3) The user has a handler set and calls exit() at the end. Then our bridge
// will be destroyed via the function we registered with atexit() (all good).
// 4) The signal is SIGABRT (abort) and the user has a handler set and exits
// the program via exit(). Then our handler will be called and we're good.
// 5) The signal is SIGABRT (abort) and the user has a handler set and returns
// from his handler. According to the man pages, when a signal handler for
// SIGABRT returns, it replaces the current handler with the default handler
// (which does a core dump) and re-raises the SIGABRT signal. So when we
// call the user's handler for SIGABRT and he returns, we kill the bridge
// because we know (and hopefully the user knew) that the process will be
// terminated anyway.
// Note: PostGres seems to ignore SIGINT at one point. SQLite exit()s after
// three SIGINTs are sent (maybe to prevent accidental ^C from killing it...)
if (old_handler != NULL) {
old_handler(signal_number);
} else {
exit(EXIT_FAILURE);
}
if (signal_number == SIGABRT) {
bridge_destroy(&bridge);
}
}
static int
bridge_if_destroy(struct bridge_if *bif)
{
if (bridge_destroy(bif->bif_name) < 0)
return (-1);
bridge_remove_bif(bif);
return (0);
}
void _bridge_exit_handler() {
bridge_destroy(&bridge);
}