Hi Laurent, Thanks for the reply, good to get some conversation going here!
>> - using a synchronous channel to send the shutdown/reboot message >> between the poweroff/reboot helpers, rather than an asynchronous >> signal. Say, have init listening on a socket, allowing the poweroff >> binary to wait and/or retry. > > That would not work either: you could receive the event before init > starts listening to the socket. That's OK, as the helper (/sbin/poweroff) has the opportunity to retry if the connect() fails (because init hasn't established the listening socket yet). The main difference is that the sender can detect failure, and retry if necessary. AF_UNIX sockets in the abstract namespace don't require a path bound to the filesystem, so perhaps they would be available early enough - or have I missed something there? [Non-Linux platforms may not support the same abstract namespace, so I'd need to implement a fallback there, but I don't (yet) know if this same race is relevant on those platforms...] I'd rather not just wear the race, as that means we've missed shutdown events, which is quite user-visible. The signal-after-reaped-grandchild approach seems okay too, if other methods aren't workable. Or even Tito's suggestion of a repeated signal, which has the advantage of a minimal change to code. Cheers, Jeremy _______________________________________________ busybox mailing list busybox@busybox.net http://lists.busybox.net/mailman/listinfo/busybox
