xref: /openbsd-src/lib/libpthread/man/pthread_setspecific.3 (revision a28daedfc357b214be5c701aa8ba8adb29a7f1c2)
1.\" $OpenBSD: pthread_setspecific.3,v 1.11 2007/05/31 19:19:37 jmc Exp $
2.\"
3.\" Copyright (c) 1996 John Birrell <jb@cimlogic.com.au>.
4.\" All rights reserved.
5.\"
6.\" Redistribution and use in source and binary forms, with or without
7.\" modification, are permitted provided that the following conditions
8.\" are met:
9.\" 1. Redistributions of source code must retain the above copyright
10.\"    notice, this list of conditions and the following disclaimer.
11.\" 2. Redistributions in binary form must reproduce the above copyright
12.\"    notice, this list of conditions and the following disclaimer in the
13.\"    documentation and/or other materials provided with the distribution.
14.\" 3. All advertising materials mentioning features or use of this software
15.\"    must display the following acknowledgement:
16.\"	This product includes software developed by John Birrell.
17.\" 4. Neither the name of the author nor the names of any co-contributors
18.\"    may be used to endorse or promote products derived from this software
19.\"    without specific prior written permission.
20.\"
21.\" THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
22.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31.\" SUCH DAMAGE.
32.\"
33.\" $FreeBSD: pthread_setspecific.3,v 1.5 1999/08/28 00:03:11 peter Exp $
34.\"
35.Dd $Mdocdate: May 31 2007 $
36.Dt PTHREAD_SETSPECIFIC 3
37.Os
38.Sh NAME
39.Nm pthread_setspecific
40.Nd set a thread-specific data value
41.Sh SYNOPSIS
42.Fd #include <pthread.h>
43.Ft int
44.Fn pthread_setspecific "pthread_key_t key" "const void *value"
45.Sh DESCRIPTION
46The
47.Fn pthread_setspecific
48function associates a thread-specific value with a
49.Fa key
50obtained via a previous call to
51.Fn pthread_key_create .
52Different threads may bind different values to the same key. These values are
53typically pointers to blocks of dynamically allocated memory that have been
54reserved for use by the calling thread.
55.Pp
56The effect of calling
57.Fn pthread_setspecific
58with a key value not obtained from
59.Fn pthread_key_create
60or after
61.Fa key
62has been deleted with
63.Fn pthread_key_delete
64is undefined.
65.Pp
66.Fn pthread_setspecific
67may be called from a thread-specific data destructor function; however, this
68may result in lost storage or infinite loops.
69.Sh RETURN VALUES
70If successful, the
71.Fn pthread_setspecific
72function will return zero.
73Otherwise an error number will be returned to indicate the error.
74.Sh ERRORS
75.Fn pthread_setspecific
76will fail if:
77.Bl -tag -width Er
78.It Bq Er ENOMEM
79Insufficient memory exists to associate the value with the
80.Fa key .
81.It Bq Er EINVAL
82The
83.Fa key
84value is invalid.
85.El
86.Sh SEE ALSO
87.Xr pthread_getspecific 3 ,
88.Xr pthread_key_create 3 ,
89.Xr pthread_key_delete 3
90.Sh STANDARDS
91.Fn pthread_setspecific
92conforms to
93.St -p1003.1-96 .
94