[screen-devel] [bug #25089] screen produces zombies

[Marcin Cieślak]

Follow-up Comment #12, bug #25089 (project screen):

The reason for this is that in the C language only some very narrow set of
library functions can be invoked from the signal handler

FreeBSD sigaction(2) manpage lists them and adds:

https://www.freebsd.org/cgi/man.cgi?query=sigaction&apropos=0&sektion=2&manpath=FreeBSD+12.1-RELEASE+and+Ports&arch=default&format=html

> All functions not in the above lists are considered to be unsafe with
> respect to signals.  That is to say, the behaviour of such functions is
> undefined when they are called from a signal handler that interrupted an
> unsafe function.  In general though, signal handlers should do little
> more than set a flag; most other actions are not safe.

Therefore it was the best practice in the signal handlers only to   set the
variable and deal with the actual handling later.

    _______________________________________________________

Reply to this item at:

  <https://savannah.gnu.org/bugs/?25089>

_______________________________________________
  Message sent via Savannah
  https://savannah.gnu.org/