CTRL+C stops all program if using RPIO.PWM about rpio

[SgtBurned]

Code? It could be that Ctrl+C is quitting because it has nothing else to run? Post your code and I will review it. Might be a similar problem to mine ( os.kill(PID, signal.SIGINT) will kill PWM aswell and shut main program down ).

[tuomas2]

I must produce separate example case for this. The problem occurs in a slightly larger code that is not open (yet). Practically there are other threads running and in main thread i have this try KeyboardException that should handle ctrl+c cleanly (and will shut down other threads cleanly as well). If this is not enough, I try to figure out simple an small code for you next weekend.

[mlv]

This is caused by source/c_pwm/pwm.c trapping all signals:

// Catch all signals possible - it is vital we kill the DMA engine
// on process exit!
static void
setup_sighandlers(void)
{
    int i;
    for (i = 0; i < 64; i++) {
        struct sigaction sa;
        memset(&sa, 0, sizeof(sa));
        sa.sa_handler = (void *) terminate;
        sigaction(i, &sa, NULL);
    }
}

I won't argue the importance of shutting down the DMA engine, but I'd like to think there's a better way of handling it (maybe be a little more discriminating? Only trap signals that would normally be fatal that don't already have handlers?).

This bit me in a different way. I have a server that's just quietly running in a tmux window. That is, until I change it's window size. A window size change sends a SIGWINCH to the process. It would normally be ignored (what care I for window sizes?), but setup_sighandlers() thinks the sky is falling when the window size changes and shuts down my server.

@tuomas2 what you can do is save the SIGINT handler and restore it afterwards. For example:

import signal
saveintsig=signal.getsignal(signal.SIGINT)

# then do the PWM setup
...
# after PWM has been setup...

signal.signal(signal.SIGINT, saveintsig)
try:
    doyourstuff()
except KeyboardInterrupt:
    sys.exit(0)

[mkj]

I think setup_sighandlers should only handle signals 1-32. 33 onwards are realtime signals. The following whitelist are safe to ignore, they don't terminate the process or are handled by Python

SIGCHLD
SIGCONT
SIGTSTP
SIGTTIN
SIGTTOU
SIGURG
SIGWINCH
SIGPIPE (by Python)
SIGINT (by Python)
SIGIO