xref: /freebsd/share/man/man4/sem.4 (revision b6a05070fa77edc7ce6e60b61623fd806e807be6)
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25.\" $FreeBSD$
26.\"
27.Dd February 7, 2014
28.Dt SEM 4
29.Os
30.Sh NAME
31.Nm sem
32.Nd POSIX semaphores
33.Sh SYNOPSIS
34To compile this driver into the kernel,
35place the following line in your
36kernel configuration file:
37.Bd -ragged -offset indent
38.Cd "options P1003_1B_SEMAPHORES"
39.Ed
40.Pp
41Alternatively, to load the driver as a
42module at boot time, place the following line in
43.Xr loader.conf 5 :
44.Bd -literal -offset indent
45sem_load="YES"
46.Ed
47.Pp
48To load the driver as a module at run-time, run the following
49command as root:
50.Bd -ragged -offset indent
51kldload sem
52.Ed
53.Sh DESCRIPTION
54The
55.Nm
56facility provides system calls used by the standard C library
57.Pq Pa libc
58to implement
59.Tn POSIX
60semaphores.
61This facility offers support for such functions as
62.Fn sem_init
63and
64.Fn sem_wait .
65It is available both as a kernel option for static inclusion and as a
66dynamic kernel module.
67.Sh SEE ALSO
68.Xr sem_destroy 3 ,
69.Xr sem_getvalue 3 ,
70.Xr sem_init 3 ,
71.Xr sem_open 3 ,
72.Xr sem_post 3 ,
73.Xr sem_wait 3 ,
74.Xr config 8 ,
75.Xr kldload 8 ,
76.Xr kldunload 8
77.Sh HISTORY
78The
79.Nm
80facility appeared in
81.Fx 5.0 .
82