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
119
120
121
122
123
  | 
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Timer Wheel
 * Copyright (C) 2016 Cumulus Networks, Inc.
 * Donald Sharp
 */
#include "zebra.h"
#include "linklist.h"
#include "frrevent.h"
#include "memory.h"
#include "wheel.h"
#include "log.h"
DEFINE_MTYPE_STATIC(LIB, TIMER_WHEEL, "Timer Wheel");
DEFINE_MTYPE_STATIC(LIB, TIMER_WHEEL_LIST, "Timer Wheel Slot List");
static int debug_timer_wheel = 0;
static void wheel_timer_thread(struct event *t);
static void wheel_timer_thread(struct event *t)
{
	struct listnode *node, *nextnode;
	unsigned long long curr_slot;
	unsigned int slots_to_skip = 1;
	struct timer_wheel *wheel;
	void *data;
	wheel = EVENT_ARG(t);
	wheel->curr_slot += wheel->slots_to_skip;
	curr_slot = wheel->curr_slot % wheel->slots;
	if (debug_timer_wheel)
		zlog_debug("%s: Wheel Slot: %lld(%lld) count: %d", __func__,
			   wheel->curr_slot, curr_slot,
			   listcount(wheel->wheel_slot_lists[curr_slot]));
	for (ALL_LIST_ELEMENTS(wheel->wheel_slot_lists[curr_slot], node,
			       nextnode, data))
		(*wheel->slot_run)(data);
	while (list_isempty(wheel->wheel_slot_lists[(curr_slot + slots_to_skip)
						    % wheel->slots])
	       && (curr_slot + slots_to_skip) % wheel->slots != curr_slot)
		slots_to_skip++;
	wheel->slots_to_skip = slots_to_skip;
	event_add_timer_msec(wheel->master, wheel_timer_thread, wheel,
			     wheel->nexttime * slots_to_skip, &wheel->timer);
}
struct timer_wheel *wheel_init(struct event_loop *master, int period,
			       size_t slots,
			       unsigned int (*slot_key)(const void *),
			       void (*slot_run)(void *), const char *run_name)
{
	struct timer_wheel *wheel;
	size_t i;
	wheel = XCALLOC(MTYPE_TIMER_WHEEL, sizeof(struct timer_wheel));
	wheel->slot_key = slot_key;
	wheel->slot_run = slot_run;
	wheel->period = period;
	wheel->slots = slots;
	wheel->curr_slot = 0;
	wheel->master = master;
	wheel->nexttime = period / slots;
	wheel->wheel_slot_lists = XCALLOC(MTYPE_TIMER_WHEEL_LIST,
					  slots * sizeof(struct list *));
	for (i = 0; i < slots; i++)
		wheel->wheel_slot_lists[i] = list_new();
	event_add_timer_msec(wheel->master, wheel_timer_thread, wheel,
			     wheel->nexttime, &wheel->timer);
	return wheel;
}
void wheel_delete(struct timer_wheel *wheel)
{
	int i;
	for (i = 0; i < wheel->slots; i++) {
		list_delete(&wheel->wheel_slot_lists[i]);
	}
	EVENT_OFF(wheel->timer);
	XFREE(MTYPE_TIMER_WHEEL_LIST, wheel->wheel_slot_lists);
	XFREE(MTYPE_TIMER_WHEEL, wheel);
}
int wheel_add_item(struct timer_wheel *wheel, void *item)
{
	long long slot;
	slot = (*wheel->slot_key)(item);
	if (debug_timer_wheel)
		zlog_debug("%s: Inserting %p: %lld %lld", __func__, item, slot,
			   slot % wheel->slots);
	listnode_add(wheel->wheel_slot_lists[slot % wheel->slots], item);
	return 0;
}
int wheel_remove_item(struct timer_wheel *wheel, void *item)
{
	long long slot;
	slot = (*wheel->slot_key)(item);
	if (debug_timer_wheel)
		zlog_debug("%s: Removing %p: %lld %lld", __func__, item, slot,
			   slot % wheel->slots);
	listnode_delete(wheel->wheel_slot_lists[slot % wheel->slots], item);
	return 0;
}
  |