[apple/libpthread.git] / man / pthread_setspecific.3

.\" Copyright (c) 1996 John Birrell <jb@cimlogic.com.au>.
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by John Birrell.
.\" 4. Neither the name of the author nor the names of any co-contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
.Dd April 4, 1996
.Dt PTHREAD_SETSPECIFIC 3
.Os
.Sh NAME
.Nm pthread_setspecific
.Nd set a thread-specific data value
.Sh SYNOPSIS
.In pthread.h
.Ft int
.Fn pthread_setspecific "pthread_key_t key" "const void *value"
.Sh DESCRIPTION
The
.Fn pthread_setspecific
function associates a thread-specific value with a
.Fa key
obtained via a previous call to
.Fn pthread_key_create .
Different threads can bind different values to the same key.
These values are
typically pointers to blocks of dynamically allocated memory that have been
reserved for use by the calling thread.
.Pp
The effect of calling
.Fn pthread_setspecific
with a key value not obtained from
.Fn pthread_key_create
or after
.Fa key
has been deleted with
.Fn pthread_key_delete
is undefined.
.Pp
The
.Fn pthread_setspecific
function may be called from a thread-specific data destructor function,
however this may result in lost storage or infinite loops.
.Sh RETURN VALUES
If successful, the
.Fn pthread_setspecific
function will return zero.
Otherwise an error number will be returned to
indicate the error.
.Sh ERRORS
The
.Fn pthread_setspecific
function will fail if:
.Bl -tag -width Er
.It Bq Er ENOMEM
Insufficient memory exists to associate the value with the
.Fa key .
.It Bq Er EINVAL
The
.Fa key
value is invalid.
.El
.Sh SEE ALSO
.Xr pthread_getspecific 3 ,
.Xr pthread_key_create 3 ,
.Xr pthread_key_delete 3
.Sh STANDARDS
The
.Fn pthread_setspecific
function conforms to
.St -p1003.1-96 .
Commit	Line	Data
f1a1da6c A	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	.\"
2546420a	31	.\" $FreeBSD$
f1a1da6c A	32	.\"
	33	.Dd April 4, 1996
	34	.Dt PTHREAD_SETSPECIFIC 3
	35	.Os
	36	.Sh NAME
	37	.Nm pthread_setspecific
	38	.Nd set a thread-specific data value
	39	.Sh SYNOPSIS
2546420a	40	.In pthread.h
f1a1da6c	41	.Ft int
2546420a	42	.Fn pthread_setspecific "pthread_key_t key" "const void *value"
f1a1da6c A	43	.Sh DESCRIPTION
	44	The
	45	.Fn pthread_setspecific
	46	function associates a thread-specific value with a
	47	.Fa key
	48	obtained via a previous call to
	49	.Fn pthread_key_create .
2546420a	50	Different threads can bind different values to the same key.
f1a1da6c A	51	These values are
	52	typically pointers to blocks of dynamically allocated memory that have been
	53	reserved for use by the calling thread.
	54	.Pp
	55	The effect of calling
	56	.Fn pthread_setspecific
	57	with a key value not obtained from
2546420a	58	.Fn pthread_key_create
f1a1da6c A	59	or after
	60	.Fa key
	61	has been deleted with
2546420a	62	.Fn pthread_key_delete
f1a1da6c A	63	is undefined.
f1a1da6c A	64	.Pp
2546420a	65	The
f1a1da6c	66	.Fn pthread_setspecific
2546420a A	67	function may be called from a thread-specific data destructor function,
2546420a A	68	however this may result in lost storage or infinite loops.
f1a1da6c	69	.Sh RETURN VALUES
2546420a	70	If successful, the
f1a1da6c A	71	.Fn pthread_setspecific
f1a1da6c A	72	function will return zero.
2546420a A	73	Otherwise an error number will be returned to
2546420a A	74	indicate the error.
f1a1da6c	75	.Sh ERRORS
2546420a	76	The
f1a1da6c	77	.Fn pthread_setspecific
2546420a	78	function will fail if:
f1a1da6c	79	.Bl -tag -width Er
2546420a A	80	.It Bq Er ENOMEM
	81	Insufficient memory exists to associate the value with the
	82	.Fa key .
f1a1da6c A	83	.It Bq Er EINVAL
	84	The
	85	.Fa key
	86	value is invalid.
f1a1da6c A	87	.El
	88	.Sh SEE ALSO
	89	.Xr pthread_getspecific 3 ,
	90	.Xr pthread_key_create 3 ,
	91	.Xr pthread_key_delete 3
	92	.Sh STANDARDS
2546420a	93	The
f1a1da6c	94	.Fn pthread_setspecific
2546420a	95	function conforms to
f1a1da6c	96	.St -p1003.1-96 .