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authorLinus Torvalds <torvalds@linux-foundation.org>2011-01-06 10:42:43 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2011-01-06 10:42:43 -0800
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))
endif
lib-y := ctype.o string.o vsprintf.o cmdline.o \
- rbtree.o radix-tree.o dump_stack.o \
+ rbtree.o radix-tree.o dump_stack.o timerqueue.o\
idr.o int_sqrt.o extable.o prio_tree.o \
sha1.o irq_regs.o reciprocal_div.o argv_split.o \
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 @@
+/*
+ * Generic Timer-queue
+ *
+ * Manages a simple queue 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/timerqueue.h>
+#include <linux/rbtree.h>
+#include <linux/module.h>
+
+/**
+ * timerqueue_add - Adds timer to timerqueue.
+ *
+ * @head: head of timerqueue
+ * @node: timer node to be added
+ *
+ * Adds the timer node to the timerqueue, sorted by the
+ * node's expires value.
+ */
+void timerqueue_add(struct timerqueue_head *head, struct timerqueue_node *node)
+{
+ struct rb_node **p = &head->head.rb_node;
+ struct rb_node *parent = NULL;
+ struct timerqueue_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 timerqueue_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;
+}
+EXPORT_SYMBOL_GPL(timerqueue_add);
+
+/**
+ * timerqueue_del - Removes a timer from the timerqueue.
+ *
+ * @head: head of timerqueue
+ * @node: timer node to be removed
+ *
+ * Removes the timer node from the timerqueue.
+ */
+void timerqueue_del(struct timerqueue_head *head, struct timerqueue_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 timerqueue_node, node) : NULL;
+ }
+ rb_erase(&node->node, &head->head);
+ RB_CLEAR_NODE(&node->node);
+}
+EXPORT_SYMBOL_GPL(timerqueue_del);
+
+/**
+ * timerqueue_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 timerqueue_node *timerqueue_iterate_next(struct timerqueue_node *node)
+{
+ struct rb_node *next;
+
+ if (!node)
+ return NULL;
+ next = rb_next(&node->node);
+ if (!next)
+ return NULL;
+ return container_of(next, struct timerqueue_node, node);
+}
+EXPORT_SYMBOL_GPL(timerqueue_iterate_next);

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