On Thursday, 23 September 2021 at 17:20:18 UTC, Steven
Schveighoffer wrote:
So imagine the sequence:
With ease!
1. ctrl-c, signal handler triggers, shutting down the loop
Just a note: there is no 'signal handler' in the program.
SIGINT/SIGTERM are **blocked**, notifications (POLLIN) are
received via epoll_wait().
2. main exits
3. GC finalizes all objects, including the Stopper and it's
members
Probably, a destructor for Signal class should be added, in which
- close fd, obtained from signalfd()
- unblock the signal (thus default signal handler is back again)
4. ctrl-c happens again, but you didn't unregister the signal
handler, so it's run again, referencing the now-deleted object.
At this point we have default signal handler
5. segfault
It's theoretically a very very small window.
But even without destructor, no segfault will happen,
because **there is no signal handler**
