/gecko_api/include/prclist.h

  1/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
  2/* ***** BEGIN LICENSE BLOCK *****
  3 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
  4 *
  5 * The contents of this file are subject to the Mozilla Public License Version
  6 * 1.1 (the "License"); you may not use this file except in compliance with
  7 * the License. You may obtain a copy of the License at
  8 * http://www.mozilla.org/MPL/
  9 *
 10 * Software distributed under the License is distributed on an "AS IS" basis,
 11 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 12 * for the specific language governing rights and limitations under the
 13 * License.
 14 *
 15 * The Original Code is the Netscape Portable Runtime (NSPR).
 16 *
 17 * The Initial Developer of the Original Code is
 18 * Netscape Communications Corporation.
 19 * Portions created by the Initial Developer are Copyright (C) 1998-2000
 20 * the Initial Developer. All Rights Reserved.
 21 *
 22 * Contributor(s):
 23 *
 24 * Alternatively, the contents of this file may be used under the terms of
 25 * either the GNU General Public License Version 2 or later (the "GPL"), or
 26 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 27 * in which case the provisions of the GPL or the LGPL are applicable instead
 28 * of those above. If you wish to allow use of your version of this file only
 29 * under the terms of either the GPL or the LGPL, and not to allow others to
 30 * use your version of this file under the terms of the MPL, indicate your
 31 * decision by deleting the provisions above and replace them with the notice
 32 * and other provisions required by the GPL or the LGPL. If you do not delete
 33 * the provisions above, a recipient may use your version of this file under
 34 * the terms of any one of the MPL, the GPL or the LGPL.
 35 *
 36 * ***** END LICENSE BLOCK ***** */
 37
 38#ifndef prclist_h___
 39#define prclist_h___
 40
 41#include "prtypes.h"
 42
 43typedef struct PRCListStr PRCList;
 44
 45/*
 46** Circular linked list
 47*/
 48struct PRCListStr {
 49    PRCList	*next;
 50    PRCList	*prev;
 51};
 52
 53/*
 54** Insert element "_e" into the list, before "_l".
 55*/
 56#define PR_INSERT_BEFORE(_e,_l)	 \
 57    PR_BEGIN_MACRO		 \
 58	(_e)->next = (_l);	 \
 59	(_e)->prev = (_l)->prev; \
 60	(_l)->prev->next = (_e); \
 61	(_l)->prev = (_e);	 \
 62    PR_END_MACRO
 63
 64/*
 65** Insert element "_e" into the list, after "_l".
 66*/
 67#define PR_INSERT_AFTER(_e,_l)	 \
 68    PR_BEGIN_MACRO		 \
 69	(_e)->next = (_l)->next; \
 70	(_e)->prev = (_l);	 \
 71	(_l)->next->prev = (_e); \
 72	(_l)->next = (_e);	 \
 73    PR_END_MACRO
 74
 75/*
 76** Return the element following element "_e"
 77*/
 78#define PR_NEXT_LINK(_e)	 \
 79    	((_e)->next)
 80/*
 81** Return the element preceding element "_e"
 82*/
 83#define PR_PREV_LINK(_e)	 \
 84    	((_e)->prev)
 85
 86/*
 87** Append an element "_e" to the end of the list "_l"
 88*/
 89#define PR_APPEND_LINK(_e,_l) PR_INSERT_BEFORE(_e,_l)
 90
 91/*
 92** Insert an element "_e" at the head of the list "_l"
 93*/
 94#define PR_INSERT_LINK(_e,_l) PR_INSERT_AFTER(_e,_l)
 95
 96/* Return the head/tail of the list */
 97#define PR_LIST_HEAD(_l) (_l)->next
 98#define PR_LIST_TAIL(_l) (_l)->prev
 99
100/*
101** Remove the element "_e" from it's circular list.
102*/
103#define PR_REMOVE_LINK(_e)	       \
104    PR_BEGIN_MACRO		       \
105	(_e)->prev->next = (_e)->next; \
106	(_e)->next->prev = (_e)->prev; \
107    PR_END_MACRO
108
109/*
110** Remove the element "_e" from it's circular list. Also initializes the
111** linkage.
112*/
113#define PR_REMOVE_AND_INIT_LINK(_e)    \
114    PR_BEGIN_MACRO		       \
115	(_e)->prev->next = (_e)->next; \
116	(_e)->next->prev = (_e)->prev; \
117	(_e)->next = (_e);	       \
118	(_e)->prev = (_e);	       \
119    PR_END_MACRO
120
121/*
122** Return non-zero if the given circular list "_l" is empty, zero if the
123** circular list is not empty
124*/
125#define PR_CLIST_IS_EMPTY(_l) \
126    ((_l)->next == (_l))
127
128/*
129** Initialize a circular list
130*/
131#define PR_INIT_CLIST(_l)  \
132    PR_BEGIN_MACRO	   \
133	(_l)->next = (_l); \
134	(_l)->prev = (_l); \
135    PR_END_MACRO
136
137#define PR_INIT_STATIC_CLIST(_l) \
138    {(_l), (_l)}
139
140#endif /* prclist_h___ */