1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
|
/*
* Generic Timer-list
*
* Manages a simple list of timers, ordered by expiration time.
* Uses rbtrees for quick list adds and expiration.
*
* NOTE: All of the following functions need to be serialized
* to avoid races. No locking is done by this libary code.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/timerlist.h>
#include <linux/rbtree.h>
/**
* timerlist_add - Adds timer to timerlist.
*
* @head: head of timerlist
* @node: timer node to be added
*
* Adds the timer node to the timerlist, sorted by the
* node's expires value.
*/
void timerlist_add(struct timerlist_head *head, struct timerlist_node *node)
{
struct rb_node **p = &head->head.rb_node;
struct rb_node *parent = NULL;
struct timerlist_node *ptr;
/* Make sure we don't add nodes that are already added */
WARN_ON_ONCE(!RB_EMPTY_NODE(&node->node));
while (*p) {
parent = *p;
ptr = rb_entry(parent, struct timerlist_node, node);
if (node->expires.tv64 < ptr->expires.tv64)
p = &(*p)->rb_left;
else
p = &(*p)->rb_right;
}
rb_link_node(&node->node, parent, p);
rb_insert_color(&node->node, &head->head);
if (!head->next || node->expires.tv64 < head->next->expires.tv64)
head->next = node;
}
/**
* timerlist_del - Removes a timer from the timerlist.
*
* @head: head of timerlist
* @node: timer node to be removed
*
* Removes the timer node from the timerlist.
*/
void timerlist_del(struct timerlist_head *head, struct timerlist_node *node)
{
WARN_ON_ONCE(RB_EMPTY_NODE(&node->node));
/* update next pointer */
if (head->next == node) {
struct rb_node *rbn = rb_next(&node->node);
head->next = rbn ?
rb_entry(rbn, struct timerlist_node, node) : NULL;
}
rb_erase(&node->node, &head->head);
RB_CLEAR_NODE(&node->node);
}
/**
* timerlist_getnext - Returns the timer with the earlies expiration time
*
* @head: head of timerlist
*
* Returns a pointer to the timer node that has the
* earliest expiration time.
*/
struct timerlist_node *timerlist_getnext(struct timerlist_head *head)
{
return head->next;
}
/**
* timerlist_iterate_next - Returns the timer after the provided timer
*
* @node: Pointer to a timer.
*
* Provides the timer that is after the given node. This is used, when
* necessary, to iterate through the list of timers in a timer list
* without modifying the list.
*/
struct timerlist_node *timerlist_iterate_next(struct timerlist_node *node)
{
struct rb_node *next;
if (!node)
return NULL;
next = rb_next(&node->node);
if (!next)
return NULL;
return container_of(next, struct timerlist_node, node);
}
|
