new file mode 100644
--- /dev/null
+++ b/src/event/ngx_event_timer.h
@@ -0,0 +1,120 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ */
+
+
+#ifndef _NGX_EVENT_TIMER_H_INCLUDED_
+#define _NGX_EVENT_TIMER_H_INCLUDED_
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+#include <ngx_event.h>
+
+
+#define NGX_TIMER_INFINITE  -1
+#define NGX_TIMER_ERROR     -2
+
+/*
+ * 32 bit timer key value resolution
+ *
+ * 1 msec - 24 days
+ * 10 msec - 8 months
+ * 50 msec - 3 years 5 months
+ * 100 msec - 6 years 10 months
+ */
+
+#define NGX_TIMER_RESOLUTION  1
+
+
+ngx_int_t ngx_event_timer_init(ngx_log_t *log);
+ngx_msec_t ngx_event_find_timer(void);
+void ngx_event_expire_timers(ngx_msec_t timer);
+
+
+#if (NGX_THREADS)
+extern ngx_mutex_t  *ngx_event_timer_mutex;
+#endif
+
+
+extern ngx_thread_volatile ngx_rbtree_t  *ngx_event_timer_rbtree;
+extern ngx_rbtree_t                       ngx_event_timer_sentinel;
+
+
+ngx_inline static void ngx_event_del_timer(ngx_event_t *ev)
+{
+    ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
+                   "event timer del: %d: %d",
+                    ngx_event_ident(ev->data), ev->rbtree_key);
+
+    if (ngx_mutex_lock(ngx_event_timer_mutex) == NGX_ERROR) {
+        return;
+    }
+
+    ngx_rbtree_delete((ngx_rbtree_t **) &ngx_event_timer_rbtree,
+                      &ngx_event_timer_sentinel,
+                      (ngx_rbtree_t *) &ev->rbtree_key);
+
+    ngx_mutex_unlock(ngx_event_timer_mutex);
+
+#if (NGX_DEBUG)
+    ev->rbtree_left = NULL;
+    ev->rbtree_right = NULL;
+    ev->rbtree_parent = NULL;
+#endif
+
+    ev->timer_set = 0;
+}
+
+
+ngx_inline static void ngx_event_add_timer(ngx_event_t *ev, ngx_msec_t timer)
+{
+    ngx_int_t  key;
+
+    key = (ngx_int_t)
+              (ngx_elapsed_msec / NGX_TIMER_RESOLUTION * NGX_TIMER_RESOLUTION
+                                              + timer) / NGX_TIMER_RESOLUTION;
+#if 0
+                             (ngx_elapsed_msec + timer) / NGX_TIMER_RESOLUTION;
+#endif
+
+    if (ev->timer_set) {
+
+        /*
+         * Use the previous timer value if a difference between them is less
+         * then 100 milliseconds.  It allows to minimize the rbtree operations
+         * for the fast connections.
+         */
+
+        if (abs(key - ev->rbtree_key) < 100 / NGX_TIMER_RESOLUTION) {
+            ngx_log_debug3(NGX_LOG_DEBUG_EVENT, ev->log, 0,
+                           "event timer: %d, old: %d, new: %d",
+                            ngx_event_ident(ev->data), ev->rbtree_key, key);
+            return;
+        }
+
+        ngx_del_timer(ev);
+    }
+
+    ev->rbtree_key = key;
+
+    ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
+                   "event timer add: %d: %d",
+                    ngx_event_ident(ev->data), ev->rbtree_key);
+
+    if (ngx_mutex_lock(ngx_event_timer_mutex) == NGX_ERROR) {
+        return;
+    }
+
+    ngx_rbtree_insert((ngx_rbtree_t **) &ngx_event_timer_rbtree,
+                      &ngx_event_timer_sentinel,
+                      (ngx_rbtree_t *) &ev->rbtree_key);
+
+    ngx_mutex_unlock(ngx_event_timer_mutex);
+
+    ev->timer_set = 1;
+}
+
+
+#endif /* _NGX_EVENT_TIMER_H_INCLUDED_ */