1
2 /*
3 * Copyright (C) Igor Sysoev
4 * Copyright (C) Nginx, Inc.
5 */
6
7
8 #ifndef _NGX_EVENT_TIMER_H_INCLUDED_
9 #define _NGX_EVENT_TIMER_H_INCLUDED_
10
11
12 #include <ngx_config.h>
13 #include <ngx_core.h>
14 #include <ngx_event.h>
15
16
17 #define NGX_TIMER_INFINITE (ngx_msec_t) -1
18
19 #define NGX_TIMER_LAZY_DELAY 300
20
21
22 ngx_int_t ngx_event_timer_init(ngx_log_t *log);
23 ngx_msec_t ngx_event_find_timer(void);
24 void ngx_event_expire_timers(void);
25 ngx_int_t ngx_event_no_timers_left(void);
26
27
28 extern ngx_rbtree_t ngx_event_timer_rbtree;
29
30
31 static ngx_inline void
ngx_event_del_timer(ngx_event_t * ev)32 ngx_event_del_timer(ngx_event_t *ev)
33 {
34 ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
35 "event timer del: %d: %M",
36 ngx_event_ident(ev->data), ev->timer.key);
37
38 ngx_rbtree_delete(&ngx_event_timer_rbtree, &ev->timer);
39
40 #if (NGX_DEBUG)
41 ev->timer.left = NULL;
42 ev->timer.right = NULL;
43 ev->timer.parent = NULL;
44 #endif
45
46 ev->timer_set = 0;
47 }
48
49
50 static ngx_inline void
ngx_event_add_timer(ngx_event_t * ev,ngx_msec_t timer)51 ngx_event_add_timer(ngx_event_t *ev, ngx_msec_t timer)
52 {
53 ngx_msec_t key;
54 ngx_msec_int_t diff;
55
56 key = ngx_current_msec + timer;
57
58 if (ev->timer_set) {
59
60 /*
61 * Use a previous timer value if difference between it and a new
62 * value is less than NGX_TIMER_LAZY_DELAY milliseconds: this allows
63 * to minimize the rbtree operations for fast connections.
64 */
65
66 diff = (ngx_msec_int_t) (key - ev->timer.key);
67
68 if (ngx_abs(diff) < NGX_TIMER_LAZY_DELAY) {
69 ngx_log_debug3(NGX_LOG_DEBUG_EVENT, ev->log, 0,
70 "event timer: %d, old: %M, new: %M",
71 ngx_event_ident(ev->data), ev->timer.key, key);
72 return;
73 }
74
75 ngx_del_timer(ev);
76 }
77
78 ev->timer.key = key;
79
80 ngx_log_debug3(NGX_LOG_DEBUG_EVENT, ev->log, 0,
81 "event timer add: %d: %M:%M",
82 ngx_event_ident(ev->data), timer, ev->timer.key);
83
84 ngx_rbtree_insert(&ngx_event_timer_rbtree, &ev->timer);
85
86 ev->timer_set = 1;
87 }
88
89
90 #endif /* _NGX_EVENT_TIMER_H_INCLUDED_ */
91