K 10
svn:author
V 3
kib
K 8
svn:date
V 27
2016-12-04T20:44:58.902246Z
K 7
svn:log
V 889
Restructure the code to handle reporting of non-exited processes from
wait(2).
- Do not acquire the process spinlock if neither WTRAPPED nor WUNTRACED
  options were passed [1].
- Extract the code to report alive process into a new helper
  report_alive_proc() and use it for trapped, stopped and continued
  childrens.

Note that the process spinlock is required around the WTRAPPED and
WUNTRACED tests, because P_STOPPED_TRACE and P_STOPPED_SIG flags are
set before other threads are stopped at the suspension point, and that
threads increment p_suspcount while owning only the process spinlock,
the process lock is dropped by them.  If the spinlock is not taken for
tests, the syscall thread might miss both p_suspcount increment and
wakeup in wakeup in thread_suspend_switch().

Based on the submission by:	mjg [1]
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week

END