/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include #include #include #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_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_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); }