1.\" $OpenBSD: pthread_getspecific.3,v 1.6 2007/05/31 19:19:36 jmc Exp $
2.\"
3.\" Copyright (c) 1996 John Birrell <jb@cimlogic.com.au>.
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33.\" $FreeBSD: pthread_getspecific.3,v 1.6 1999/08/28 00:03:06 peter Exp $
34.\"
35.Dd $Mdocdate: May 31 2007 $
36.Dt PTHREAD_GETSPECIFIC 3
37.Os
38.Sh NAME
39.Nm pthread_getspecific
40.Nd get a thread-specific data value
41.Sh SYNOPSIS
42.Fd #include <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
64.Fn pthread_getspecific
65may be called from a thread-specific data destructor function.
66.Sh RETURN VALUES
67The
68.Fn pthread_getspecific
69function will return the thread-specific data value associated with the given
70.Fa key .
71If no thread-specific data value is associated with
72.Fa key ,
73then the value NULL is returned.
74.Sh ERRORS
75None.
76.Sh SEE ALSO
77.Xr pthread_key_create 3 ,
78.Xr pthread_key_delete 3 ,
79.Xr pthread_setspecific 3
80.Sh STANDARDS
81.Fn pthread_getspecific
82conforms to
83.St -p1003.1-96 .
84