1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ 2 /* 3 * The contents of this file are subject to the Mozilla Public 4 * License Version 1.1 (the "License"); you may not use this file 5 * except in compliance with the License. You may obtain a copy of 6 * the License at http://www.mozilla.org/MPL/ 7 * 8 * Software distributed under the License is distributed on an "AS 9 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or 10 * implied. See the License for the specific language governing 11 * rights and limitations under the License. 12 * 13 * The Original Code is the Netscape Portable Runtime (NSPR). 14 * 15 * The Initial Developer of the Original Code is Netscape 16 * Communications Corporation. Portions created by Netscape are 17 * Copyright (C) 1998-2000 Netscape Communications Corporation. All 18 * Rights Reserved. 19 * 20 * Contributor(s): 21 * 22 * Alternatively, the contents of this file may be used under the 23 * terms of the GNU General Public License Version 2 or later (the 24 * "GPL"), in which case the provisions of the GPL are applicable 25 * instead of those above. If you wish to allow use of your 26 * version of this file only under the terms of the GPL and not to 27 * allow others to use your version of this file under the MPL, 28 * indicate your decision by deleting the provisions above and 29 * replace them with the notice and other provisions required by 30 * the GPL. If you do not delete the provisions above, a recipient 31 * may use your version of this file under either the MPL or the 32 * GPL. 33 */ 34 35 #ifndef prclist_h___ 36 #define prclist_h___ 37 38 #include "prtypes.h" 39 40 typedef struct PRCListStr PRCList; 41 42 /* 43 ** Circular linked list 44 */ 45 struct PRCListStr { 46 PRCList *next; 47 PRCList *prev; 48 }; 49 50 /* 51 ** Insert element "_e" into the list, before "_l". 52 */ 53 #define PR_INSERT_BEFORE(_e,_l) \ 54 PR_BEGIN_MACRO \ 55 (_e)->next = (_l); \ 56 (_e)->prev = (_l)->prev; \ 57 (_l)->prev->next = (_e); \ 58 (_l)->prev = (_e); \ 59 PR_END_MACRO 60 61 /* 62 ** Insert element "_e" into the list, after "_l". 63 */ 64 #define PR_INSERT_AFTER(_e,_l) \ 65 PR_BEGIN_MACRO \ 66 (_e)->next = (_l)->next; \ 67 (_e)->prev = (_l); \ 68 (_l)->next->prev = (_e); \ 69 (_l)->next = (_e); \ 70 PR_END_MACRO 71 72 /* 73 ** Return the element following element "_e" 74 */ 75 #define PR_NEXT_LINK(_e) \ 76 ((_e)->next) 77 /* 78 ** Return the element preceding element "_e" 79 */ 80 #define PR_PREV_LINK(_e) \ 81 ((_e)->prev) 82 83 /* 84 ** Append an element "_e" to the end of the list "_l" 85 */ 86 #define PR_APPEND_LINK(_e,_l) PR_INSERT_BEFORE(_e,_l) 87 88 /* 89 ** Insert an element "_e" at the head of the list "_l" 90 */ 91 #define PR_INSERT_LINK(_e,_l) PR_INSERT_AFTER(_e,_l) 92 93 /* Return the head/tail of the list */ 94 #define PR_LIST_HEAD(_l) (_l)->next 95 #define PR_LIST_TAIL(_l) (_l)->prev 96 97 /* 98 ** Remove the element "_e" from it's circular list. 99 */ 100 #define PR_REMOVE_LINK(_e) \ 101 PR_BEGIN_MACRO \ 102 (_e)->prev->next = (_e)->next; \ 103 (_e)->next->prev = (_e)->prev; \ 104 PR_END_MACRO 105 106 /* 107 ** Remove the element "_e" from it's circular list. Also initializes the 108 ** linkage. 109 */ 110 #define PR_REMOVE_AND_INIT_LINK(_e) \ 111 PR_BEGIN_MACRO \ 112 (_e)->prev->next = (_e)->next; \ 113 (_e)->next->prev = (_e)->prev; \ 114 (_e)->next = (_e); \ 115 (_e)->prev = (_e); \ 116 PR_END_MACRO 117 118 /* 119 ** Return non-zero if the given circular list "_l" is empty, zero if the 120 ** circular list is not empty 121 */ 122 #define PR_CLIST_IS_EMPTY(_l) \ 123 ((_l)->next == (_l)) 124 125 /* 126 ** Initialize a circular list 127 */ 128 #define PR_INIT_CLIST(_l) \ 129 PR_BEGIN_MACRO \ 130 (_l)->next = (_l); \ 131 (_l)->prev = (_l); \ 132 PR_END_MACRO 133 134 #define PR_INIT_STATIC_CLIST(_l) \ 135 {(_l), (_l)} 136 137 #endif /* prclist_h___ */ 138