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Diffstat (limited to 'lib/libc/gen/sem_post.3')
-rw-r--r-- | lib/libc/gen/sem_post.3 | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/lib/libc/gen/sem_post.3 b/lib/libc/gen/sem_post.3 new file mode 100644 index 0000000..67559cc --- /dev/null +++ b/lib/libc/gen/sem_post.3 @@ -0,0 +1,78 @@ +.\" 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. +.\" +.\" $FreeBSD$ +.\" +.Dd February 15, 2000 +.Dt SEM_POST 3 +.Os +.Sh NAME +.Nm sem_post +.Nd increment (unlock) a semaphore +.Sh LIBRARY +.Lb libc +.Sh SYNOPSIS +.In semaphore.h +.Ft int +.Fn sem_post "sem_t *sem" +.Sh DESCRIPTION +The +.Fn sem_post +function increments (unlocks) the semaphore pointed to by +.Fa sem . +If there are threads blocked on the semaphore when +.Fn sem_post +is called, then the highest priority thread that has been blocked the longest on +the semaphore will be allowed to return from +.Fn sem_wait . +.Pp +The +.Fn sem_post +function is signal-reentrant and may be called within signal handlers. +.Sh RETURN VALUES +.Rv -std sem_post +.Sh ERRORS +The +.Fn sem_post +function will fail if: +.Bl -tag -width Er +.It Bq Er EINVAL +The +.Fa sem +argument +points to an invalid semaphore. +.El +.Sh SEE ALSO +.Xr sem_getvalue 3 , +.Xr sem_trywait 3 , +.Xr sem_wait 3 , +.Xr sem 4 +.Sh STANDARDS +The +.Fn sem_post +function conforms to +.St -p1003.1-96 . |