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/*
* Copyright (C) Igor Sysoev
* Copyright (C) Nginx, Inc.
*/
#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_event.h>
#if (NGX_THREADS)
ngx_mutex_t *ngx_event_timer_mutex;
#endif
ngx_thread_volatile ngx_rbtree_t ngx_event_timer_rbtree;
static ngx_rbtree_node_t ngx_event_timer_sentinel;
/*
* the event timer rbtree may contain the duplicate keys, however,
* it should not be a problem, because we use the rbtree to find
* a minimum timer value only
*/
ngx_int_t
ngx_event_timer_init(ngx_log_t *log)
{
ngx_rbtree_init(&ngx_event_timer_rbtree, &ngx_event_timer_sentinel,
ngx_rbtree_insert_timer_value);
#if (NGX_THREADS)
if (ngx_event_timer_mutex) {
ngx_event_timer_mutex->log = log;
return NGX_OK;
}
ngx_event_timer_mutex = ngx_mutex_init(log, 0);
if (ngx_event_timer_mutex == NULL) {
return NGX_ERROR;
}
#endif
return NGX_OK;
}
ngx_msec_t
ngx_event_find_timer(void)
{
ngx_msec_int_t timer;
ngx_rbtree_node_t *node, *root, *sentinel;
if (ngx_event_timer_rbtree.root == &ngx_event_timer_sentinel) {
return NGX_TIMER_INFINITE;
}
ngx_mutex_lock(ngx_event_timer_mutex);
root = ngx_event_timer_rbtree.root;
sentinel = ngx_event_timer_rbtree.sentinel;
node = ngx_rbtree_min(root, sentinel);
ngx_mutex_unlock(ngx_event_timer_mutex);
timer = (ngx_msec_int_t) node->key - (ngx_msec_int_t) ngx_current_msec;
return (ngx_msec_t) (timer > 0 ? timer : 0);
}
void
ngx_event_expire_timers(void)
{
ngx_event_t *ev;
ngx_rbtree_node_t *node, *root, *sentinel;
sentinel = ngx_event_timer_rbtree.sentinel;
for ( ;; ) {
ngx_mutex_lock(ngx_event_timer_mutex);
root = ngx_event_timer_rbtree.root;
if (root == sentinel) {
return;
}
node = ngx_rbtree_min(root, sentinel);
/* node->key <= ngx_current_time */
if ((ngx_msec_int_t) node->key - (ngx_msec_int_t) ngx_current_msec <= 0)
{
ev = (ngx_event_t *) ((char *) node - offsetof(ngx_event_t, timer));
#if (NGX_THREADS)
if (ngx_threaded && ngx_trylock(ev->lock) == 0) {
/*
* We cannot change the timer of the event that is being
* handled by another thread. And we cannot easy walk
* the rbtree to find next expired timer so we exit the loop.
* However, it should be a rare case when the event that is
* being handled has an expired timer.
*/
ngx_log_debug1(NGX_LOG_DEBUG_EVENT, ev->log, 0,
"event %p is busy in expire timers", ev);
break;
}
#endif
ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
"event timer del: %d: %M",
ngx_event_ident(ev->data), ev->timer.key);
ngx_rbtree_delete(&ngx_event_timer_rbtree, &ev->timer);
ngx_mutex_unlock(ngx_event_timer_mutex);
#if (NGX_DEBUG)
ev->timer.left = NULL;
ev->timer.right = NULL;
ev->timer.parent = NULL;
#endif
ev->timer_set = 0;
#if (NGX_THREADS)
if (ngx_threaded) {
ev->posted_timedout = 1;
ngx_post_event(ev, &ngx_posted_events);
ngx_unlock(ev->lock);
continue;
}
#endif
ev->timedout = 1;
ev->handler(ev);
continue;
}
break;
}
ngx_mutex_unlock(ngx_event_timer_mutex);
}
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