release/src/router/nginx/src/event/ngx_event_timer.h

   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
  26
  27 #if (NGX_THREADS)
  28 extern ngx_mutex_t  *ngx_event_timer_mutex;
  29 #endif
  30
  31
  32 extern ngx_thread_volatile ngx_rbtree_t  ngx_event_timer_rbtree;
  33
  34
  35 static ngx_inline void
  36 ngx_event_del_timer(ngx_event_t *ev)
  37 {
  38     ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
  39                    "event timer del: %d: %M",
  40                     ngx_event_ident(ev->data), ev->timer.key);
  41
  42     ngx_mutex_lock(ngx_event_timer_mutex);
  43
  44     ngx_rbtree_delete(&ngx_event_timer_rbtree, &ev->timer);
  45
  46     ngx_mutex_unlock(ngx_event_timer_mutex);
  47
  48 #if (NGX_DEBUG)
  49     ev->timer.left = NULL;
  50     ev->timer.right = NULL;
  51     ev->timer.parent = NULL;
  52 #endif
  53
  54     ev->timer_set = 0;
  55 }
  56
  57
  58 static ngx_inline void
  59 ngx_event_add_timer(ngx_event_t *ev, ngx_msec_t timer)
  60 {
  61     ngx_msec_t      key;
  62     ngx_msec_int_t  diff;
  63
  64     key = ngx_current_msec + timer;
  65
  66     if (ev->timer_set) {
  67
  68         /*
  69          * Use a previous timer value if difference between it and a new
  70          * value is less than NGX_TIMER_LAZY_DELAY milliseconds: this allows
  71          * to minimize the rbtree operations for fast connections.
  72          */
  73
  74         diff = (ngx_msec_int_t) (key - ev->timer.key);
  75
  76         if (ngx_abs(diff) < NGX_TIMER_LAZY_DELAY) {
  77             ngx_log_debug3(NGX_LOG_DEBUG_EVENT, ev->log, 0,
  78                            "event timer: %d, old: %M, new: %M",
  79                             ngx_event_ident(ev->data), ev->timer.key, key);
  80             return;
  81         }
  82
  83         ngx_del_timer(ev);
  84     }
  85
  86     ev->timer.key = key;
  87
  88     ngx_log_debug3(NGX_LOG_DEBUG_EVENT, ev->log, 0,
  89                    "event timer add: %d: %M:%M",
  90                     ngx_event_ident(ev->data), timer, ev->timer.key);
  91
  92     ngx_mutex_lock(ngx_event_timer_mutex);
  93
  94     ngx_rbtree_insert(&ngx_event_timer_rbtree, &ev->timer);
  95
  96     ngx_mutex_unlock(ngx_event_timer_mutex);
  97
  98     ev->timer_set = 1;
  99 }
 100
 101
 102 #endif /* _NGX_EVENT_TIMER_H_INCLUDED_ */