svn commit: r225172 - head/lib/libc/sys

[Konstantin Belousov]

Author: kib
Date: Thu Aug 25 10:00:38 2011
New Revision: 225172
URL: http://svn.freebsd.org/changeset/base/225172

Log:
  Clarify the behaviour of sigwait() on signal interruption, and note
  the difference between sigwait() and sigtimedwait()/sigwaitinfo().
  
  Approved by:	re (bz)

Modified:
  head/lib/libc/sys/sigwait.2
  head/lib/libc/sys/sigwaitinfo.2

Modified: head/lib/libc/sys/sigwait.2
==============================================================================
--- head/lib/libc/sys/sigwait.2	Thu Aug 25 09:38:33 2011	(r225171)
+++ head/lib/libc/sys/sigwait.2	Thu Aug 25 10:00:38 2011	(r225172)
@@ -27,7 +27,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd November 11, 2005
+.Dd August 24, 2011
 .Dt SIGWAIT 2
 .Os
 .Sh NAME
@@ -82,6 +82,14 @@ selected, it will be the lowest numbered
 The selection order between realtime
 and non-realtime signals, or between multiple pending non-realtime signals,
 is unspecified.
+.Sh IMPLEMENTATION NOTES
+The
+.Fn sigwait
+function is implemented as a wrapper around the
+.Fn __sys_sigwait
+system call, which retries the call on
+.Er EINTR
+error.
 .Sh RETURN VALUES
 If successful,
 .Fn sigwait

Modified: head/lib/libc/sys/sigwaitinfo.2
==============================================================================
--- head/lib/libc/sys/sigwaitinfo.2	Thu Aug 25 09:38:33 2011	(r225171)
+++ head/lib/libc/sys/sigwaitinfo.2	Thu Aug 25 10:00:38 2011	(r225172)
@@ -27,7 +27,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd November 11, 2005
+.Dd August 24, 2011
 .Dt SIGTIMEDWAIT 2
 .Os
 .Sh NAME
@@ -116,6 +116,16 @@ except that the selected signal number s
 member, and the cause of the signal shall be stored in the
 .Va si_code
 member.
+Besides this, the
+.Fn sigwaitinfo
+and
+.Fn sigtimedwait
+system calls may return
+.Er EINTR
+if interrupted by signal, which is not allowed for the
+.Fn sigwait
+function.
+.Pp
 If any value is queued to the selected signal, the first such queued
 value is dequeued and, if the info argument is
 .Pf non- Dv NULL ,