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.
67A call to
68.Fn pthread_getspecific
69for the thread-specific data key being destroyed returns the value NULL,
70unless the value is changed (after the destructor starts) by a call to
71.Fn pthread_setspecific .
72.Sh RETURN VALUES
73The
74.Fn pthread_getspecific
75function will return the thread-specific data value associated with the given
76.Fa key .
77If no thread-specific data value is associated with
78.Fa key ,
79then the value NULL is returned.
80.Sh ERRORS
81None.
82.Sh SEE ALSO
83.Xr pthread_key_create 3 ,
84.Xr pthread_key_delete 3 ,
85.Xr pthread_setspecific 3
86.Sh STANDARDS
87The
88.Fn pthread_getspecific
89function conforms to
90.St -p1003.1-96 .
91