From 3bb8b93140bb6511c7bcd235b327cdf09815030e Mon Sep 17 00:00:00 2001
From: yamt <yamt@NetBSD.org>
Date: Sat, 10 Aug 2002 05:05:24 +0000
Subject: [PATCH] more about sigsetjmp/siglongjmp. from openbsd.

---
 lib/libc/gen/setjmp.3 | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/lib/libc/gen/setjmp.3 b/lib/libc/gen/setjmp.3
index 538e84ad9584..06820a7f0d57 100644
--- a/lib/libc/gen/setjmp.3
+++ b/lib/libc/gen/setjmp.3
@@ -1,4 +1,4 @@
-.\"	$NetBSD: setjmp.3,v 1.10 2002/07/10 14:37:14 yamt Exp $
+.\"	$NetBSD: setjmp.3,v 1.11 2002/08/10 05:05:24 yamt Exp $
 .\"
 .\" Copyright (c) 1990, 1991, 1993
 .\"	The Regents of the University of California.  All rights reserved.
@@ -137,7 +137,30 @@ The
 function
 pairs save and restore the signal mask if the argument
 .Fa savemask
-is non-zero, otherwise only the register set and the stack are saved.
+is non-zero.
+Otherwise, only the register set and the stack are saved.
+.Pp
+In other words,
+.Fn setjmp Ns / Ns Fn longjmp
+are functionally equivalent to
+.Fn sigsetjmp Ns / Ns Fn siglongjmp
+when
+.Fn sigsetjmp
+is called with a non-zero
+.Fa savemask
+argument.
+Conversely,
+.Fn _setjmp Ns / Ns Fn _longjmp
+are functionally equivalent to
+.Fn sigsetjmp Ns / Ns Fn siglongjmp
+when
+.Fn sigsetjmp
+is called with a zero-value
+.Fa savemask .
+.Pp
+The
+.Fn sigsetjmp Ns / Ns Fn siglongjmp
+interfaces are preferred for maximum portability.
 .Sh ERRORS
 If the contents of the
 .Fa env