xref: /freebsd/share/man/man3/pthread_setspecific.3 (revision a8445737e740901f5f2c8d24c12ef7fc8b00134e)
1.\" Copyright (c) 1996 John Birrell <jb@cimlogic.com.au>.
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31.Dd April 4, 1996
32.Dt PTHREAD_SETSPECIFIC 3
33.Os BSD 4
34.Sh NAME
35.Nm pthread_setspecific
36.Nd set a thread-specific data value
37.Sh SYNOPSIS
38.Fd #include <pthread.h>
39.Ft int
40.Fn pthread_setspecific "pthread_key_t key" "const void *value"
41.Sh DESCRIPTION
42The
43.Fn pthread_setspecific
44function associates a thread-specific value with a
45.Fa key
46obtained via a previous call to
47.Fn pthread_key_create .
48Different threads man bind different values to the same key. These values are
49typically pointers to blocks of dynamically allocated memory that have been
50reserved for use by the calling thread.
51.Pp
52The effect of calling
53.Fn pthread_setspecific
54with a key value 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
62.Fn pthread_setspecific
63may be called from a thread-specific data destructor function, however this
64may result in lost storage or infinite loops.
65.Sh RETURN VALUES
66If successful,  the
67.Fn pthread_setspecific
68function will return zero. Otherwise an error number will be returned to
69indicate the error.
70.Sh ERRORS
71.Fn pthread_setspecific
72will fail if:
73.Bl -tag -width Er
74.It Bq Er ENOMEM
75Insufficient memory exists to associate the value with the
76.Fa key .
77.It Bq Er EINVAL
78The
79.Fa key
80value is invalid.
81.El
82.Pp
83.Sh SEE ALSO
84.Xr pthread_getspecific 3 ,
85.Xr pthread_key_create 3 ,
86.Xr pthread_key_delete 3
87.Sh STANDARDS
88.Fn pthread_setspecific
89conforms to ISO/IEC 9945-1 ANSI/IEEE
90.Pq Dq Tn POSIX
91Std 1003.1 Second Edition 1996-07-12.
92