FreeBSD prior to 10.0 does not automatically stir on fork(). Same with
current NetBSD. If arc4random_stir() is present assume is needed and
call it instead of srand().
This fixes the problem that ngIRCd can't do any IDENT lookups because
of the socket has already been closed in the child process.
The bug has been introduced starting with ngIRCd 17 ... :-(
(commit ID 6ebb31ab35)
we do not need this for cryptographic purposes, but we can do better
than plain srandom(getpid()).
Also, keep in mind that rng state is inherited across fork(), so re-init
it in the child.
Allows to defer/queue signal processing for execution on the next
event dispatch call, i.e. we can perform any signal action in
normal, non-signal context.
Example uses:
- Reload everything on HUP without writing a global "SIGHUP_received"
variable
- Dump status of internal Lists on SIGUSR1, etc.
This avoids a race and potentionally killing the wrong process on
systems that use randomized process IDs; now the child itself is
responsible to exit in a timely manner using SIGALRM.
The new "module" proc.c is used for functions dealing with child
processes. At the moment, it is only used by the asynchronous resolver.
All the functions already implemented habe been migrated from the
resolver code base, and the rest of the ngIRCd source code has been
adepted to the new namespace and calling conventions.
The goal is to develop "generic" process handling functions that can
be used for other purposes as well, e.g. running processes on client
connects etc.
Federico G. Schwindt