1.\" Copyright (c) 2012 Vishesh Yadav 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. The name of the author may not be used to endorse or promote products 13.\" derived from this software without specific prior written permission. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25.\" 26.\" 27.Dd October 23, 2012 28.Dt IDR 9 29.Os 30.Sh NAME 31.Nm idr , 32.Nm idr_destroy , 33.Nm idr_find , 34.Nm idr_for_each , 35.Nm idr_get_new , 36.Nm idr_get_new_above , 37.Nm idr_init , 38.Nm idr_pre_get , 39.Nm idr_remove , 40.Nm idr_remove_all , 41.Nm idr_replace 42.Nd integer ID management library 43.Sh SYNOPSIS 44.In sys/idr.h 45.Ft void 46.Fn idr_destroy "struct idr *idp" 47.Ft void * 48.Fn idr_find "struct idr *idp" "int id" 49.Ft int 50.Fn idr_for_each "struct idr *idp" "int (*fn)(int id, void *p, void *data)" "void *data" 51.Ft int 52.Fn idr_get_new "struct idr *idp" "void *ptr" "int *id" 53.Ft int 54.Fn idr_get_new_above "struct idr *idp" "void *ptr" "int sid" "int *id" 55.Ft void 56.Fn idr_init "struct idr *idp" 57.Ft int 58.Fn idr_pre_get "struct idr *idp" "unsigned gfp_mask" 59.Ft void 60.Fn idr_remove "struct idr *idp" "int id" 61.Ft void 62.Fn idr_remove_all "struct idr *idp" 63.Ft void * 64.Fn idr_replace "struct idr *idp" "void *ptr" "int id" 65.Sh DESCRIPTION 66The 67.Fn idr_destroy 68function frees all resources taken by the specified 69.Nm 70handle 71.Fa idp . 72.Pp 73The 74.Fn idr_find 75function returns the data pointer that is mapped with the specified 76.Fa id . 77.Pp 78The 79.Fn idr_for_each 80function iterates through all pointers registered with the specified 81.Nm 82handle 83.Fa idp 84and calls the callback function 85.Fn fn 86for each pointer. 87It is not safe to modify the 88.Nm 89tree through the callback function. 90If the callback function returns a non-zero integer, it stops and returns the 91value. 92.Pp 93The 94.Fn idr_get_new 95and 96.Fn idr_get_new_above 97functions allocate a new integer mapped with the specified pointer 98.Fa ptr . 99The new ID will be stored in 100.Fa id . 101If the tree becomes full, these functions will return 102.Er -EAGAIN . 103In this case, 104.Fn idr_pre_get 105should be called to grow the tree. 106.Pp 107The 108.Fn idr_init 109function initialize an 110.Nm 111handle that will be used by other functions of the API. 112The 113.Fn idr_pre_get 114function should be called prior to calling the 115.Fn idr_get_new* 116functions. 117It preallocates enough memory for subsequent calls to 118.Fn idr_get_new* 119functions. 120This function should be called without any locks held. 121It returns 0 if enough memory couldn't be allocated, otherwise 1. 122The 123.Sq Va gfp_mask 124parameter is only present for compatibility with the Linux implementation of 125this API and is unused on 126.Dx . 127. 128.Pp 129The 130.Fn idr_remove 131function removes the specified 132.Fa id 133from the tree. 134.Pp 135The 136.Fn idr_remove_all 137function removes all entries in the 138.Nm 139tree 140.Fa idp . 141.Pp 142The 143.Fn idr_replace 144function replaces the pointer for the specified 145.Fa id 146with the new pointer 147.Fa ptr . 148It returns 149.Dv NULL 150if the pointer is not found. 151This behavior is different from the Linux API. 152