1.\" Copyright (c) 1996 John Birrell <jb@cimlogic.com.au>.
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31.Dd April 4, 1996
32.Dt PTHREAD_GETSPECIFIC 3
33.Os
34.Sh NAME
35.Nm pthread_getspecific
36.Nd get a thread-specific data value
37.Sh LIBRARY
38.Lb libpthread
39.Sh SYNOPSIS
40.In pthread.h
41.Ft void *
42.Fn pthread_getspecific "pthread_key_t key"
43.Sh DESCRIPTION
44The
45.Fn pthread_getspecific
46function returns the value currently bound to the specified
47.Fa key
48on behalf of the calling thread.
49.Pp
50The effect of calling
51.Fn pthread_getspecific
52with a
53.Fa key
54value not obtained from
55.Fn pthread_key_create
56or after
57.Fa key
58has been deleted with
59.Fn pthread_key_delete
60is undefined.
61.Pp
62The
63.Fn pthread_getspecific
64function may be called from a thread-specific data destructor function.
65A call to
66.Fn pthread_getspecific
67for the thread-specific data key being destroyed returns the value NULL,
68unless the value is changed (after the destructor starts) by a call to
69.Fn pthread_setspecific .
70.Sh RETURN VALUES
71The
72.Fn pthread_getspecific
73function will return the thread-specific data value associated with the given
74.Fa key .
75If no thread-specific data value is associated with
76.Fa key ,
77then the value NULL is returned.
78.Sh ERRORS
79None.
80.Sh SEE ALSO
81.Xr pthread_key_create 3 ,
82.Xr pthread_key_delete 3 ,
83.Xr pthread_setspecific 3
84.Sh STANDARDS
85The
86.Fn pthread_getspecific
87function conforms to
88.St -p1003.1-96 .
89