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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /lib/timerqueue.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | lib/timerqueue.c | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/lib/timerqueue.c b/lib/timerqueue.c new file mode 100644 index 0000000000..cdb9c76584 --- /dev/null +++ b/lib/timerqueue.c @@ -0,0 +1,84 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * 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 library code. + */ + +#include <linux/bug.h> +#include <linux/timerqueue.h> +#include <linux/rbtree.h> +#include <linux/export.h> + +#define __node_2_tq(_n) \ + rb_entry((_n), struct timerqueue_node, node) + +static inline bool __timerqueue_less(struct rb_node *a, const struct rb_node *b) +{ + return __node_2_tq(a)->expires < __node_2_tq(b)->expires; +} + +/** + * 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. Returns true if the newly added timer is the first expiring timer in + * the queue. + */ +bool timerqueue_add(struct timerqueue_head *head, struct timerqueue_node *node) +{ + /* Make sure we don't add nodes that are already added */ + WARN_ON_ONCE(!RB_EMPTY_NODE(&node->node)); + + return rb_add_cached(&node->node, &head->rb_root, __timerqueue_less); +} +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. Returns true if the queue is + * not empty after the remove. + */ +bool timerqueue_del(struct timerqueue_head *head, struct timerqueue_node *node) +{ + WARN_ON_ONCE(RB_EMPTY_NODE(&node->node)); + + rb_erase_cached(&node->node, &head->rb_root); + RB_CLEAR_NODE(&node->node); + + return !RB_EMPTY_ROOT(&head->rb_root.rb_root); +} +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); |