From 75331fe5be2c94da9c5ef4db51ded9f039f78410 Mon Sep 17 00:00:00 2001
From: yar <yar@FreeBSD.org>
Date: Mon, 17 May 2004 23:09:10 +0000
Subject: Clarify and extend paragraphs on interoperation of fcntl(2),
 flock(2), and lockf(3) advisory locks. Add such a paragraph to the flock(2)
 manpage for the sake of consistency.

Reviewed by:	Cyrille Lefevre and Kirk McKusick on -arch
MFC after:	2 weeks
---
 lib/libc/gen/lockf.3 | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

(limited to 'lib/libc/gen/lockf.3')

diff --git a/lib/libc/gen/lockf.3 b/lib/libc/gen/lockf.3
index abb00ac..63cf669 100644
--- a/lib/libc/gen/lockf.3
+++ b/lib/libc/gen/lockf.3
@@ -173,10 +173,22 @@ error.
 .Pp
 The
 .Fn lockf ,
-.Xr fcntl 2
+.Xr fcntl 2 ,
 and
 .Xr flock 2
-locks may be safely used concurrently.
+locks are compatible.
+Processes using different locking interfaces can cooperate
+over the same file safely.
+However, only one of such interfaces should be used within
+the same process.
+If a file is locked by a process through
+.Xr flock 2 ,
+any record within the file will be seen as locked
+from the viewpoint of another process using
+.Xr fcntl 2
+or
+.Fn lockf ,
+and vice versa.
 .Pp
 Blocking on a section is interrupted by any signal.
 .Sh RETURN VALUES
-- 
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