man3/sem_close.3

   1 .\" Copyright (C) 2006 Michael Kerrisk <mtk.manpages@gmail.com>
   2 .\"
   3 .\" SPDX-License-Identifier: Linux-man-pages-copyleft
   4 .\"
   5 .TH sem_close 3 (date) "Linux man-pages (unreleased)"
   6 .SH NAME
   7 sem_close \- close a named semaphore
   8 .SH LIBRARY
   9 POSIX threads library
  10 .RI ( libpthread ", " \-lpthread )
  11 .SH SYNOPSIS
  12 .nf
  13 .B #include <semaphore.h>
  14 .PP
  15 .BI "int sem_close(sem_t *" sem );
  16 .fi
  17 .SH DESCRIPTION
  18 .BR sem_close ()
  19 closes the named semaphore referred to by
  20 .IR sem ,
  21 allowing any resources that the system has allocated to
  22 the calling process for this semaphore to be freed.
  23 .SH RETURN VALUE
  24 On success
  25 .BR sem_close ()
  26 returns 0; on error, \-1 is returned, with
  27 .I errno
  28 set to indicate the error.
  29 .SH ERRORS
  30 .TP
  31 .B EINVAL
  32 .I sem
  33 is not a valid semaphore.
  34 .SH ATTRIBUTES
  35 For an explanation of the terms used in this section, see
  36 .BR attributes (7).
  37 .ad l
  38 .nh
  39 .TS
  40 allbox;
  41 lbx lb lb
  42 l l l.
  43 Interface       Attribute       Value
  44 T{
  45 .BR sem_close ()
  46 T}      Thread safety   MT-Safe
  47 .TE
  48 .hy
  49 .ad
  50 .sp 1
  51 .SH STANDARDS
  52 POSIX.1-2001, POSIX.1-2008.
  53 .SH NOTES
  54 All open named semaphores are automatically closed on process
  55 termination, or upon
  56 .BR execve (2).
  57 .SH SEE ALSO
  58 .BR sem_getvalue (3),
  59 .BR sem_open (3),
  60 .BR sem_post (3),
  61 .BR sem_unlink (3),
  62 .BR sem_wait (3),
  63 .BR sem_overview (7)