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authorLinus Torvalds <torvalds@linux-foundation.org>2011-01-06 13:42:43 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2011-01-06 13:42:43 -0500
commitdda5f0a372873bca5f0b1d1866d7784dffd8b675 (patch)
tree1f745951b51ef9dcd127ca3c65ecb1d2ce4967c2 /lib
parent65b2074f84be2287e020839e93b4cdaaf60eb37c (diff)
parent88606e80da0e8d862a42ee19e5bb60b01b940ea7 (diff)
Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: MAINTAINERS: Update timer related entries timers: Use this_cpu_read timerqueue: Make timerqueue_getnext() static inline hrtimer: fix timerqueue conversion flub hrtimers: Convert hrtimers to use timerlist infrastructure timers: Fixup allmodconfig build issue timers: Rename timerlist infrastructure to timerqueue timers: Introduce timerlist infrastructure. hrtimer: Remove stale comment on curr_timer timer: Warn when del_timer_sync() is called in hardirq context timer: Del_timer_sync() can be used in softirq context timer: Make try_to_del_timer_sync() the same on SMP and UP posix-timers: Annotate lock_timer() timer: Permit statically-declared work with deferrable timers time: Use ARRAY_SIZE macro in timecompare.c timer: Initialize the field slack of timer_list timer_list: Remove alignment padding on 64 bit when CONFIG_TIMER_STATS time: Compensate for rounding on odd-frequency clocksources Fix up trivial conflict in MAINTAINERS
Diffstat (limited to 'lib')
-rw-r--r--lib/Makefile2
-rw-r--r--lib/timerqueue.c107
2 files changed, 108 insertions, 1 deletions
diff --git a/lib/Makefile b/lib/Makefile
index e6a3763b8212..9e2db72d128e 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -8,7 +8,7 @@ KBUILD_CFLAGS = $(subst -pg,,$(ORIG_CFLAGS))
8endif 8endif
9 9
10lib-y := ctype.o string.o vsprintf.o cmdline.o \ 10lib-y := ctype.o string.o vsprintf.o cmdline.o \
11 rbtree.o radix-tree.o dump_stack.o \ 11 rbtree.o radix-tree.o dump_stack.o timerqueue.o\
12 idr.o int_sqrt.o extable.o prio_tree.o \ 12 idr.o int_sqrt.o extable.o prio_tree.o \
13 sha1.o irq_regs.o reciprocal_div.o argv_split.o \ 13 sha1.o irq_regs.o reciprocal_div.o argv_split.o \
14 proportions.o prio_heap.o ratelimit.o show_mem.o \ 14 proportions.o prio_heap.o ratelimit.o show_mem.o \
diff --git a/lib/timerqueue.c b/lib/timerqueue.c
new file mode 100644
index 000000000000..e3a1050e6820
--- /dev/null
+++ b/lib/timerqueue.c
@@ -0,0 +1,107 @@
1/*
2 * Generic Timer-queue
3 *
4 * Manages a simple queue of timers, ordered by expiration time.
5 * Uses rbtrees for quick list adds and expiration.
6 *
7 * NOTE: All of the following functions need to be serialized
8 * to avoid races. No locking is done by this libary code.
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 */
24
25#include <linux/timerqueue.h>
26#include <linux/rbtree.h>
27#include <linux/module.h>
28
29/**
30 * timerqueue_add - Adds timer to timerqueue.
31 *
32 * @head: head of timerqueue
33 * @node: timer node to be added
34 *
35 * Adds the timer node to the timerqueue, sorted by the
36 * node's expires value.
37 */
38void timerqueue_add(struct timerqueue_head *head, struct timerqueue_node *node)
39{
40 struct rb_node **p = &head->head.rb_node;
41 struct rb_node *parent = NULL;
42 struct timerqueue_node *ptr;
43
44 /* Make sure we don't add nodes that are already added */
45 WARN_ON_ONCE(!RB_EMPTY_NODE(&node->node));
46
47 while (*p) {
48 parent = *p;
49 ptr = rb_entry(parent, struct timerqueue_node, node);
50 if (node->expires.tv64 < ptr->expires.tv64)
51 p = &(*p)->rb_left;
52 else
53 p = &(*p)->rb_right;
54 }
55 rb_link_node(&node->node, parent, p);
56 rb_insert_color(&node->node, &head->head);
57
58 if (!head->next || node->expires.tv64 < head->next->expires.tv64)
59 head->next = node;
60}
61EXPORT_SYMBOL_GPL(timerqueue_add);
62
63/**
64 * timerqueue_del - Removes a timer from the timerqueue.
65 *
66 * @head: head of timerqueue
67 * @node: timer node to be removed
68 *
69 * Removes the timer node from the timerqueue.
70 */
71void timerqueue_del(struct timerqueue_head *head, struct timerqueue_node *node)
72{
73 WARN_ON_ONCE(RB_EMPTY_NODE(&node->node));
74
75 /* update next pointer */
76 if (head->next == node) {
77 struct rb_node *rbn = rb_next(&node->node);
78
79 head->next = rbn ?
80 rb_entry(rbn, struct timerqueue_node, node) : NULL;
81 }
82 rb_erase(&node->node, &head->head);
83 RB_CLEAR_NODE(&node->node);
84}
85EXPORT_SYMBOL_GPL(timerqueue_del);
86
87/**
88 * timerqueue_iterate_next - Returns the timer after the provided timer
89 *
90 * @node: Pointer to a timer.
91 *
92 * Provides the timer that is after the given node. This is used, when
93 * necessary, to iterate through the list of timers in a timer list
94 * without modifying the list.
95 */
96struct timerqueue_node *timerqueue_iterate_next(struct timerqueue_node *node)
97{
98 struct rb_node *next;
99
100 if (!node)
101 return NULL;
102 next = rb_next(&node->node);
103 if (!next)
104 return NULL;
105 return container_of(next, struct timerqueue_node, node);
106}
107EXPORT_SYMBOL_GPL(timerqueue_iterate_next);