From 940003aae4b377da53e62c8838831e666a2ed6ba Mon Sep 17 00:00:00 2001 From: jasone Date: Wed, 16 Feb 2000 19:31:53 +0000 Subject: Add man pages for the sem_*() functions. Approved by: jkh --- lib/libpthread/man/sem_getvalue.3 | 77 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 77 insertions(+) create mode 100644 lib/libpthread/man/sem_getvalue.3 (limited to 'lib/libpthread/man/sem_getvalue.3') diff --git a/lib/libpthread/man/sem_getvalue.3 b/lib/libpthread/man/sem_getvalue.3 new file mode 100644 index 0000000..be0cbae --- /dev/null +++ b/lib/libpthread/man/sem_getvalue.3 @@ -0,0 +1,77 @@ +.\" Copyright (C) 2000 Jason Evans . +.\" All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice(s), this list of conditions and the following disclaimer as +.\" the first lines of this file unmodified other than the possible +.\" addition of one or more copyright notices. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice(s), this list of conditions and the following disclaimer in +.\" the documentation and/or other materials provided with the +.\" distribution. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY +.\" EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR +.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE +.\" LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR +.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF +.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR +.\" BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, +.\" WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE +.\" OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, +.\" EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +.\" +.\" $FreeBSD$ +.Dd February 15, 2000 +.Dt SEM_GETVALUE 3 +.Os +.Sh NAME +.Nm sem_getvalue +.Nd get the value of a semaphore +.Sh SYNOPSIS +.Fd #include +.Ft int +.Fn sem_getvalue "sem_t *sem" "int *sval" +.Sh DESCRIPTION +The +.Fn sem_getvalue +function sets the variable pointed to by +.Fa sval +to the current value of the semaphore pointed to by +.Fa sem , +as of the time that the call to +.Fn sem_getvalue +is actually run. +.Sh RETURN VALUES +If successful, +.Fn sem_getvalue +returns 0. Otherwise, -1 is returned and +.Va errno +is set to indicate the type of +error. +.Sh ERRORS +.Fn sem_getvalue +will fail if: +.Bl -tag -width Er +.It Bq Er EINVAL +.Fa sem +points to an invalid semaphore. +.El +.Sh SEE ALSO +.Xr sem_post 3 , +.Xr sem_wait 3 , +.Xr sem_trywait 3 +.Sh STANDARDS +.Fn sem_getvalue +conforms to ISO/IEC 9945-1 ANSI/IEEE +.Pq Dq Tn POSIX +Std 1003.1 1996 Edition. +.Pp +The value of the semaphore is never negative, even if there are threads blocked +on the semaphore. POSIX is somewhat ambiguous in its wording with regard to +what the value of the semaphore should be if there are blocked waiting threads, +but this behavior is conformant, given the wording of the specification. -- cgit v1.1