1 #ifndef foollistfoo 2 #define foollistfoo 3 4 /*** 5 This file is part of PulseAudio. 6 7 Copyright 2004-2006 Lennart Poettering 8 9 PulseAudio is free software; you can redistribute it and/or modify 10 it under the terms of the GNU Lesser General Public License as 11 published by the Free Software Foundation; either version 2.1 of the 12 License, or (at your option) any later version. 13 14 PulseAudio is distributed in the hope that it will be useful, but 15 WITHOUT ANY WARRANTY; without even the implied warranty of 16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 17 General Public License for more details. 18 19 You should have received a copy of the GNU Lesser General Public 20 License along with PulseAudio; if not, see <http://www.gnu.org/licenses/>. 21 ***/ 22 23 /* Some macros for maintaining doubly linked lists */ 24 25 /* The head of the linked list. Use this in the structure that shall 26 * contain the head of the linked list */ 27 #define PA_LLIST_HEAD(t,name) \ 28 t *name 29 30 /* The pointers in the linked list's items. Use this in the item structure */ 31 #define PA_LLIST_FIELDS(t) \ 32 t *next, *prev 33 34 /* Initialize the list's head */ 35 #define PA_LLIST_HEAD_INIT(t,item) \ 36 do { \ 37 (item) = (t*) NULL; } \ 38 while(0) 39 40 /* Initialize a list item */ 41 #define PA_LLIST_INIT(t,item) \ 42 do { \ 43 t *_item = (item); \ 44 pa_assert(_item); \ 45 _item->prev = _item->next = NULL; \ 46 } while(0) 47 48 /* Prepend an item to the list */ 49 #define PA_LLIST_PREPEND(t,head,item) \ 50 do { \ 51 t **_head = &(head), *_item = (item); \ 52 pa_assert(_item); \ 53 if ((_item->next = *_head)) \ 54 _item->next->prev = _item; \ 55 _item->prev = NULL; \ 56 *_head = _item; \ 57 } while (0) 58 59 /* Remove an item from the list */ 60 #define PA_LLIST_REMOVE(t,head,item) \ 61 do { \ 62 t **_head = &(head), *_item = (item); \ 63 pa_assert(_item); \ 64 if (_item->next) \ 65 _item->next->prev = _item->prev; \ 66 if (_item->prev) \ 67 _item->prev->next = _item->next; \ 68 else { \ 69 pa_assert(*_head == _item); \ 70 *_head = _item->next; \ 71 } \ 72 _item->next = _item->prev = NULL; \ 73 } while(0) 74 75 /* Find the head of the list */ 76 #define PA_LLIST_FIND_HEAD(t,item,head) \ 77 do { \ 78 t **_head = (head), *_item = (item); \ 79 *_head = _item; \ 80 pa_assert(_head); \ 81 while ((*_head)->prev) \ 82 *_head = (*_head)->prev; \ 83 } while (0) 84 85 /* Insert an item after another one (a = where, b = what) */ 86 #define PA_LLIST_INSERT_AFTER(t,head,a,b) \ 87 do { \ 88 t **_head = &(head), *_a = (a), *_b = (b); \ 89 pa_assert(_b); \ 90 if (!_a) { \ 91 if ((_b->next = *_head)) \ 92 _b->next->prev = _b; \ 93 _b->prev = NULL; \ 94 *_head = _b; \ 95 } else { \ 96 if ((_b->next = _a->next)) \ 97 _b->next->prev = _b; \ 98 _b->prev = _a; \ 99 _a->next = _b; \ 100 } \ 101 } while (0) 102 103 #define PA_LLIST_FOREACH(i,head) \ 104 for (i = (head); i; i = i->next) 105 106 #define PA_LLIST_FOREACH_SAFE(i,n,head) \ 107 for (i = (head); i && ((n = i->next), 1); i = n) 108 109 #endif 110