[nunwuo]

> Does running the self-pipe trick on a separate thread solve that issue? It seems like it's basically equivalent to signalfd (neither worse nor better, unless you're worried about platform-specific thread bugs): you end up with a signal mask on your main thread, but you also avoid EINTR on your main thread. Any possible pipe lockup just happens on the signal-handling thread, so the mainloop can keep running and eventually dequeue signals.

There's no need for threads. Set the pipe to non-blocking and ignore the write() error if it's EAGAIN/EWOULDBLOCK. See my response above for why dropping writes if a byte already exists in the pipe is okay.

[geofft]

Sure, but that doesn't solve the EINTR problem. If you accept signal-handler interruptions on threads where you actually do work, then you risk interrupting system calls on those threads, and even SA_RESTART isn't guaranteed to work all of the time. That's what a separate thread (or signalfd) wins you.

(But yes, setting it non-blocking is correct.)