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Diffstat (limited to 'lib/libc_r/man/sem_getvalue.3')
-rw-r--r-- | lib/libc_r/man/sem_getvalue.3 | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/lib/libc_r/man/sem_getvalue.3 b/lib/libc_r/man/sem_getvalue.3 new file mode 100644 index 00000000000..4b76fddd9ac --- /dev/null +++ b/lib/libc_r/man/sem_getvalue.3 @@ -0,0 +1,74 @@ +.\" $OpenBSD: sem_getvalue.3,v 1.1 2002/01/28 19:24:03 fgsch Exp $ +.\" Copyright (C) 2000 Jason Evans <jasone@FreeBSD.org>. +.\" 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: src/lib/libc_r/man/sem_getvalue.3,v 1.9 2001/10/01 16:09:09 ru Exp $ +.Dd February 15, 2000 +.Dt SEM_GETVALUE 3 +.Os +.Sh NAME +.Nm sem_getvalue +.Nd get the value of a semaphore +.\" .Sh LIBRARY +.\" .Lb libc_r +.Sh SYNOPSIS +.In semaphore.h +.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 +.Rv -std sem_getvalue +.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_trywait 3 , +.Xr sem_wait 3 +.Sh STANDARDS +.Fn sem_getvalue +conforms to +.St -p1003.1-96 . +.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. |