URL: https://github.com/SSSD/sssd/pull/107 Title: #107: WATCHDOG: Avoid non async-signal-safe from the signal_handler
jhrozek commented: """ On Mon, Dec 12, 2016 at 07:30:30AM -0800, Simo Sorce wrote: > well you could have a globalk variable for the watchdog and change it from a > custom signal handler, but the point of the watchdog is to go thorugh the > tevent handler instead so that we are sure the machinery is working and not > stuck somwhere. > Resetting directly from the singal handler would bypass all processing and > therefore render the watchdog useless I guess. The problem here (as I understand it, Pavel or Fabiano can correct me if I'm wrong) is that the watchdog increases the counter inside a POSIX signal handler, but resets the counter in a tevent timer (to make sure the mainloop is being processed). Now, if the time drifts, we still are receiving the monotonic SIGRT signals into the POSIX handlers, but because the tevent timer never gets invoked (it's set to be invoked in a time in the future, because the time drifted), we never reset the counter. We can detect the time has drifted in the POSIX SIGRT handler, the question I'm trying to answer is how should we restart the tevent timer when we receive the SIGRT signal, but we because we are in the POSIX handler, we are quite restriced in what we can do.. """ See the full comment at https://github.com/SSSD/sssd/pull/107#issuecomment-266462611
_______________________________________________ sssd-devel mailing list -- sssd-devel@lists.fedorahosted.org To unsubscribe send an email to sssd-devel-le...@lists.fedorahosted.org
