blob: 17d25360fc2b64b5c95764a387640ec818920718 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
|
.\" Copyright, Xavier Leroy <Xavier.Leroy@inria.fr>
.\" Copyright 2023, Alejandro Colomar <alx@kernel.org>
.\"
.\" SPDX-License-Identifier: Linux-man-pages-copyleft
.\"
.TH pthread_once 3 (date) "Linux man-pages (unreleased)"
.
.
.SH NAME
pthread_once
\-
once-only initialization
.
.
.SH SYNOPSIS
.B #include <pthread.h>
.P
.BI "pthread_once_t " once_control " = PTHREAD_ONCE_INIT;"
.P
.BI "int pthread_once(pthread_once_t *" once_control ", void (*" init_routine ") (void));"
.
.
.SH DESCRIPTION
The purpose of \fBpthread_once\fP is
to ensure that a piece of initialization code is executed at most once.
The \fIonce_control\fP argument points to a static or extern variable
statically initialized to \fBPTHREAD_ONCE_INIT\fP.
.P
The first time \fBpthread_once\fP is called
with a given \fIonce_control\fP argument,
it calls \fIinit_routine\fP with no argument
and changes the value of the \fIonce_control\fP variable
to record that initialization has been performed.
Subsequent calls to \fBpthread_once\fP
with the same \fBonce_control\fP argument
do nothing.
.
.
.SH "RETURN VALUE"
\fBpthread_once\fP always returns 0.
.
.
.SH ERRORS
None.
|
