xref: /freebsd/share/man/man3/pthread_setspecific.3 (revision 4cf49a43559ed9fdad601bdcccd2c55963008675)
1.\" Copyright (c) 1996 John Birrell <jb@cimlogic.com.au>.
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31.\" $FreeBSD$
32.\"
33.Dd April 4, 1996
34.Dt PTHREAD_SETSPECIFIC 3
35.Os BSD 4
36.Sh NAME
37.Nm pthread_setspecific
38.Nd set a thread-specific data value
39.Sh SYNOPSIS
40.Fd #include <pthread.h>
41.Ft int
42.Fn pthread_setspecific "pthread_key_t key" "const void *value"
43.Sh DESCRIPTION
44The
45.Fn pthread_setspecific
46function associates a thread-specific value with a
47.Fa key
48obtained via a previous call to
49.Fn pthread_key_create .
50Different threads man bind different values to the same key. These values are
51typically pointers to blocks of dynamically allocated memory that have been
52reserved for use by the calling thread.
53.Pp
54The effect of calling
55.Fn pthread_setspecific
56with a key value 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_setspecific
65may be called from a thread-specific data destructor function, however this
66may result in lost storage or infinite loops.
67.Sh RETURN VALUES
68If successful,  the
69.Fn pthread_setspecific
70function will return zero. Otherwise an error number will be returned to
71indicate the error.
72.Sh ERRORS
73.Fn pthread_setspecific
74will fail if:
75.Bl -tag -width Er
76.It Bq Er ENOMEM
77Insufficient memory exists to associate the value with the
78.Fa key .
79.It Bq Er EINVAL
80The
81.Fa key
82value is invalid.
83.El
84.Pp
85.Sh SEE ALSO
86.Xr pthread_getspecific 3 ,
87.Xr pthread_key_create 3 ,
88.Xr pthread_key_delete 3
89.Sh STANDARDS
90.Fn pthread_setspecific
91conforms to ISO/IEC 9945-1 ANSI/IEEE
92.Pq Dq Tn POSIX
93Std 1003.1 Second Edition 1996-07-12.
94