xref: /freebsd/share/man/man3/pthread_getspecific.3 (revision 1669d8afc64812c8d2d1d147ae1fd42ff441e1b1)
1.\" Copyright (c) 1996 John Birrell <jb@cimlogic.com.au>.
2.\" All rights reserved.
3.\"
4.\" Redistribution and use in source and binary forms, with or without
5.\" modification, are permitted provided that the following conditions
6.\" are met:
7.\" 1. Redistributions of source code must retain the above copyright
8.\"    notice, this list of conditions and the following disclaimer.
9.\" 2. Redistributions in binary form must reproduce the above copyright
10.\"    notice, this list of conditions and the following disclaimer in the
11.\"    documentation and/or other materials provided with the distribution.
12.\" 3. All advertising materials mentioning features or use of this software
13.\"    must display the following acknowledgement:
14.\"	This product includes software developed by John Birrell.
15.\" 4. Neither the name of the author nor the names of any co-contributors
16.\"    may be used to endorse or promote products derived from this software
17.\"    without specific prior written permission.
18.\"
19.\" THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
20.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29.\" SUCH DAMAGE.
30.\"
31.\" $FreeBSD$
32.\"
33.Dd April 4, 1996
34.Dt PTHREAD_GETSPECIFIC 3
35.Os
36.Sh NAME
37.Nm pthread_getspecific
38.Nd get a thread-specific data value
39.Sh LIBRARY
40.Lb libpthread
41.Sh SYNOPSIS
42.In pthread.h
43.Ft void *
44.Fn pthread_getspecific "pthread_key_t key"
45.Sh DESCRIPTION
46The
47.Fn pthread_getspecific
48function returns the value currently bound to the specified
49.Fa key
50on behalf of the calling thread.
51.Pp
52The effect of calling
53.Fn pthread_getspecific
54with a
55.Fa key
56value not obtained from
57.Fn pthread_key_create
58or after
59.Fa key
60has been deleted with
61.Fn pthread_key_delete
62is undefined.
63.Pp
64The
65.Fn pthread_getspecific
66function may be called from a thread-specific data destructor function.
67.Sh RETURN VALUES
68The
69.Fn pthread_getspecific
70function will return the thread-specific data value associated with the given
71.Fa key .
72If no thread-specific data value is associated with
73.Fa key ,
74then the value NULL is returned.
75.Sh ERRORS
76None.
77.Sh SEE ALSO
78.Xr pthread_key_create 3 ,
79.Xr pthread_key_delete 3 ,
80.Xr pthread_setspecific 3
81.Sh STANDARDS
82The
83.Fn pthread_getspecific
84function conforms to
85.St -p1003.1-96 .
86