1.\" $NetBSD: specificdata.9,v 1.7 2018/06/15 22:27:40 pgoyette Exp $ 2.\" 3.\" Copyright (c) 2010 The NetBSD Foundation, Inc. 4.\" All rights reserved. 5.\" 6.\" This code is derived from software contributed to The NetBSD Foundation 7.\" by Jason R. Thorpe 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 19.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 20.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 21.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 22.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28.\" POSSIBILITY OF SUCH DAMAGE. 29.\" 30.Dd June 16, 2018 31.Dt SPECIFICDATA 9 32.Os 33.Sh NAME 34.Nm specificdata , 35.Nm specificdata_domain_create , 36.Nm specificdata_domain_delete , 37.Nm specificdata_key_create , 38.Nm specificdata_key_delete , 39.Nm specificdata_init , 40.Nm specificdata_fini , 41.Nm specificdata_getspecific , 42.Nm specificdata_getspecific_unlocked , 43.Nm specificdata_setspecific , 44.Nm specificdata_setspecific_nowait 45.Nd manipulate arbitrary data attached to objects 46.Sh SYNOPSIS 47.In sys/specificdata.h 48.Ft specificdata_domain_t 49.Fn specificdata_domain_create 50.Ft void 51.Fn specificdata_domain_delete "specificdata_domain_t sd" 52.Ft int 53.Fn specificdata_key_create "specificdata_domain_t sd" \ 54"specificdata_key_t *keyp" "specificdata_dtor_t dtor" 55.Ft void 56.Fn specificdata_key_delete "specificdata_domain_t sd" "specificdata_key_t key" 57.Ft int 58.Fn specificdata_init "specificdata_domain_t sd" "specificdata_reference *ref" 59.Ft void 60.Fn specificdata_fini "specificdata_domain_t sd" "specificdata_reference *ref" 61.Ft "void *" 62.Fn specificdata_getspecific "specificdata_domain_t sd" \ 63"specificdata_reference *ref" "specificdata_key_t key" 64.Ft "void *" 65.Fn specificdata_getspecific_unlocked "specificdata_domain_t sd" \ 66"specificdata_reference *ref" "specificdata_key_t key" 67.Ft void 68.Fn specificdata_setspecific "specificdata_domain_t sd" \ 69"specificdata_reference *ref" "specificdata_key_t key" "void *data" 70.Ft int 71.Fn specificdata_setspecific_nowait "specificdata_domain_t sd" \ 72"specificdata_reference *ref" "specificdata_key_t key" "void *data" 73.Sh DESCRIPTION 74The 75.Nm 76facility provides a mechanism for storing arbitrary data, identified by 77an index key, within containers which exist within the objects associated 78with a particular domain. 79.Sh FUNCTIONS 80.Bl -tag -width abcd 81.It Fn specificdata_domain_create 82Create and initialize a new domain. 83.It Fn specificdata_domain_delete sd 84Deletes domain 85.Fa sd . 86.It Fn specificdata_key_create sd keyp dtor 87Create a new key for 88.Fa sd . 89If the 90.Fa dtor 91argument is not 92.Dv NULL , 93it specifies a destructor which will be called when a datum associated 94with the specified key is deleted from a container within the 95.Fa sd . 96The unique identifier of the created key is returned in 97.Fa keyp . 98.It Fn specificdata_key_delete sd key 99Delete a key for 100.Fa sd , 101and delete any associated data from all containers within the domain. 102.It Fn specificdata_init sd ref 103Initialize the container 104.Fa ref 105for use in 106.Fa sd . 107.It Fn specificdata_fini sd ref 108Destroy the container 109.Fa ref , 110and destroy all of the data stuffed into the container. 111.It Fn specificdata_getspecific sd ref key 112Retrieve the datum from the container 113.Fa ref 114associated with 115.Fa key . 116.It Fn specificdata_getspecific_unlocked sd ref key 117Retrieve the datum from the container 118.Fa ref 119associated with 120.Fa key 121in a lockless manner. 122Care must be taken to ensure that no other thread could cause 123.Fa ref 124to become invalid (i.e. point at the wrong container) by issuing a 125.Fn setspecific 126call or by destroying the container. 127.It Fn specificdata_setspecific sd ref key data 128Store 129.Fa data 130in the container 131.Fa ref 132and associate it with 133.Fa key . 134If a datum has previously been stored, the new value replaces the original; 135the original value is not destroyed, i.e. its destructor is not invoked. 136Note that there is no provision for removing a datum without replacing it. 137.It Fn specificdata_setspecific_nowait sd ref key data 138(Unimplemented) 139.El 140.Sh CODE REFERENCES 141The 142.Nm 143functionality is implemented in 144.Pa sys/kern/subr_specificdata.c . 145.Pp 146The header file 147.In sys/sys/specificdata.h 148describes the public interface. 149.Sh HISTORY 150The 151.Nm 152subsystem first appeared in 153.Nx 4.0 . 154.Sh AUTHORS 155.An -nosplit 156The 157.Nm 158subsystem was written by 159.An Jason Thorpe Aq Mt thorpej@NetBSD.org . 160This manual page was written by 161.An Paul Goyette Aq Mt pgoyette@NetBSD.org . 162