1/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2/* This Source Code Form is subject to the terms of the Mozilla Public
3 * License, v. 2.0. If a copy of the MPL was not distributed with this
4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
5
6#ifndef prclist_h___
7#define prclist_h___
8
9#include "prtypes.h"
10
11typedef struct PRCListStr PRCList;
12
13/*
14** Circular linked list
15*/
16struct PRCListStr {
17 PRCList *next;
18 PRCList *prev;
19};
20
21/*
22** Insert element "_e" into the list, before "_l".
23*/
24#define PR_INSERT_BEFORE(_e,_l) \
25 PR_BEGIN_MACRO \
26 (_e)->next = (_l); \
27 (_e)->prev = (_l)->prev; \
28 (_l)->prev->next = (_e); \
29 (_l)->prev = (_e); \
30 PR_END_MACRO
31
32/*
33** Insert element "_e" into the list, after "_l".
34*/
35#define PR_INSERT_AFTER(_e,_l) \
36 PR_BEGIN_MACRO \
37 (_e)->next = (_l)->next; \
38 (_e)->prev = (_l); \
39 (_l)->next->prev = (_e); \
40 (_l)->next = (_e); \
41 PR_END_MACRO
42
43/*
44** Return the element following element "_e"
45*/
46#define PR_NEXT_LINK(_e) \
47 ((_e)->next)
48/*
49** Return the element preceding element "_e"
50*/
51#define PR_PREV_LINK(_e) \
52 ((_e)->prev)
53
54/*
55** Append an element "_e" to the end of the list "_l"
56*/
57#define PR_APPEND_LINK(_e,_l) PR_INSERT_BEFORE(_e,_l)
58
59/*
60** Insert an element "_e" at the head of the list "_l"
61*/
62#define PR_INSERT_LINK(_e,_l) PR_INSERT_AFTER(_e,_l)
63
64/* Return the head/tail of the list */
65#define PR_LIST_HEAD(_l) (_l)->next
66#define PR_LIST_TAIL(_l) (_l)->prev
67
68/*
69** Remove the element "_e" from it's circular list.
70*/
71#define PR_REMOVE_LINK(_e) \
72 PR_BEGIN_MACRO \
73 (_e)->prev->next = (_e)->next; \
74 (_e)->next->prev = (_e)->prev; \
75 PR_END_MACRO
76
77/*
78** Remove the element "_e" from it's circular list. Also initializes the
79** linkage.
80*/
81#define PR_REMOVE_AND_INIT_LINK(_e) \
82 PR_BEGIN_MACRO \
83 (_e)->prev->next = (_e)->next; \
84 (_e)->next->prev = (_e)->prev; \
85 (_e)->next = (_e); \
86 (_e)->prev = (_e); \
87 PR_END_MACRO
88
89/*
90** Return non-zero if the given circular list "_l" is empty, zero if the
91** circular list is not empty
92*/
93#define PR_CLIST_IS_EMPTY(_l) \
94 ((_l)->next == (_l))
95
96/*
97** Initialize a circular list
98*/
99#define PR_INIT_CLIST(_l) \
100 PR_BEGIN_MACRO \
101 (_l)->next = (_l); \
102 (_l)->prev = (_l); \
103 PR_END_MACRO
104
105#define PR_INIT_STATIC_CLIST(_l) \
106 {(_l), (_l)}
107
108#endif /* prclist_h___ */
109