Module Name: src
Committed By: riastradh
Date: Sun May 3 04:05:29 UTC 2020
Modified Files:
src/share/man/man9: condvar.9
Log Message:
Add a note about setting the timeout to zero _and_ returning success.
To generate a diff of this commit:
cvs rdiff -u -r1.24 -r1.25 src/share/man/man9/condvar.9
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/share/man/man9/condvar.9
diff -u src/share/man/man9/condvar.9:1.24 src/share/man/man9/condvar.9:1.25
--- src/share/man/man9/condvar.9:1.24 Sun May 3 04:05:00 2020
+++ src/share/man/man9/condvar.9 Sun May 3 04:05:28 2020
@@ -1,4 +1,4 @@
-.\" $NetBSD: condvar.9,v 1.24 2020/05/03 04:05:00 riastradh Exp $
+.\" $NetBSD: condvar.9,v 1.25 2020/05/03 04:05:28 riastradh Exp $
.\"
.\" Copyright (c) 2006, 2007, 2008, 2020 The NetBSD Foundation, Inc.
.\" All rights reserved.
@@ -230,6 +230,19 @@ subtract the time elapsed from
.Fa bt
in place, or set it to zero if there is no time remaining.
.Pp
+Note that
+.Fn cv_timedwaitbt
+and
+.Fn cv_timedwaitbt_sig
+may return zero indicating success, rather than
+.Er EWOULDBLOCK ,
+even if they set the timeout to zero; this means that the caller must
+re-check the condition in order to avoid potentially losing a
+.Fn cv_signal ,
+but the
+.Em next
+wait will time out immediately.
+.Pp
The hint
.Fa epsilon ,
which can be
