svn commit: r258894 - head/etc

[Colin Percival]

Author: cperciva
Date: Tue Dec  3 21:55:57 2013
New Revision: 258894
URL: http://svnweb.freebsd.org/changeset/base/258894

Log:
  The rc system aggressively caches the contents of /etc/rc.conf in order to
  improve boot performance; this produces arguably astonishing (non-)results
  if /etc/rc.conf is modified during the boot process.
  
  Since performance considerations make it infeasible to automatically detect
  if the cached /etc/rc.conf parameters should be invalidated, provide a
  mechanism for explicitly requesting that /etc/rc.conf be reloaded: Catch
  SIGALRM and reload /etc/rc.conf if it is received.
  
  Discussed on:	freebsd-rc
  MFC after:	3 days

Modified:
  head/etc/rc

Modified: head/etc/rc
==============================================================================
--- head/etc/rc	Tue Dec  3 21:35:25 2013	(r258893)
+++ head/etc/rc	Tue Dec  3 21:55:57 2013	(r258894)
@@ -71,6 +71,11 @@ fi
 . /etc/rc.subr
 load_rc_config 'XXX'
 
+# If we receive a SIGALRM, re-source /etc/rc.conf; this allows rc.d
+# scripts to perform "boot-time configuration" including enabling and
+# disabling rc.d scripts which appear later in the boot order.
+trap "_rc_conf_loaded=false; load_rc_config 'XXX'" ALRM
+
 skip="-s nostart"
 if [ `/sbin/sysctl -n security.jail.jailed` -eq 1 ]; then
 	skip="$skip -s nojail"