--- a/auto/os/linux
+++ b/auto/os/linux
@@ -21,6 +21,7 @@ ngx_func_test="int efd = 0, fd = 1, n;
 
 if [ $ngx_found = yes ]; then
     have=HAVE_EPOLL . auto/have
+    have=HAVE_CLEAR_EVENT . auto/have
     CORE_SRCS="$CORE_SRCS $EPOLL_SRCS"
     EVENT_MODULES="$EVENT_MODULES $EPOLL_MODULE"
     EVENT_FOUND=YES

--- a/src/event/modules/ngx_epoll_module.c
+++ b/src/event/modules/ngx_epoll_module.c
@@ -111,8 +111,8 @@ ngx_event_module_t  ngx_epoll_module_ctx
         ngx_epoll_del_event,             /* delete an event */
         ngx_epoll_add_event,             /* enable an event */
         ngx_epoll_del_event,             /* disable an event */
-        ngx_epoll_add_connection,        /* add an connection */
-        ngx_epoll_del_connection,        /* delete an connection */
+        NULL,                            /* add an connection */
+        NULL,                            /* delete an connection */
         ngx_epoll_process_events,        /* process the events */
         ngx_epoll_init,                  /* init the events */
         ngx_epoll_done,                  /* done the events */
@@ -167,7 +167,11 @@ static int ngx_epoll_init(ngx_cycle_t *c
 
     ngx_event_actions = ngx_epoll_module_ctx.actions;
 
-    ngx_event_flags = NGX_USE_EDGE_EVENT;
+#if (HAVE_CLEAR_EVENT)
+    ngx_event_flags = NGX_USE_CLEAR_EVENT;
+#else
+    ngx_event_flags = NGX_USE_LEVEL_EVENT;
+#endif
 
     return NGX_OK;
 }
@@ -191,33 +195,53 @@ static void ngx_epoll_done(ngx_cycle_t *
 
 static int ngx_epoll_add_event(ngx_event_t *ev, int event, u_int flags)
 {
+    int                  op, prev;
+    ngx_event_t         *e;
+    ngx_connection_t    *c;
     struct epoll_event   ee;
-    ngx_connection_t    *c;
 
     c = ev->data;
 
-#if (NGX_READ_EVENT != EPOLLIN) || (NGX_WRITE_EVENT != EPOLLOUT)
     if (event == NGX_READ_EVENT) {
+        e = c->write;
+        prev = EPOLLOUT;
+#if (NGX_READ_EVENT != EPOLLIN)
         event = EPOLLIN;
-
-    } else {
-        event = EPOLLOUT;
-    }
 #endif
 
-    ee.events = event|EPOLLET;
-    ee.data.ptr = (void *) ((uintptr_t) c | c->read->instance);
+    } else {
+        e = c->read;
+        prev = EPOLLIN;
+#if (NGX_WRITE_EVENT != EPOLLOUT)
+        event = EPOLLOUT;
+#endif
+    }
+
+    if (e->active) {
+        op = EPOLL_CTL_MOD;
+        event |= prev;
 
-    ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0,
-                   "epoll add event: fd:%d ev:%08X", c->fd, ee.events);
+    } else {
+        op = EPOLL_CTL_ADD;
+    }
+
+    ee.events = event | flags;
+    ee.data.ptr = (void *) ((uintptr_t) c | ev->instance);
 
-    if (epoll_ctl(ep, EPOLL_CTL_ADD, c->fd, &ee) == -1) {
-        ngx_log_error(NGX_LOG_ALERT, c->log, ngx_errno,
-                      "epoll_ctl(EPOLL_CTL_MOD, %d) failed", c->fd);
+    ngx_log_debug3(NGX_LOG_DEBUG_EVENT, ev->log, 0,
+                   "epoll add event: fd:%d op:%d ev:%08X",
+                   c->fd, op, ee.events);
+
+    if (epoll_ctl(ep, op, c->fd, &ee) == -1) {
+        ngx_log_error(NGX_LOG_ALERT, ev->log, ngx_errno,
+                      "epoll_ctl(%d, %d) failed", op, c->fd);
         return NGX_ERROR;
     }
 
     ev->active = 1;
+#if 0
+    ev->oneshot = (flags & NGX_ONESHOT_EVENT) ? 1 : 0;
+#endif
 
     return NGX_OK;
 }
@@ -225,20 +249,51 @@ static int ngx_epoll_add_event(ngx_event
 
 static int ngx_epoll_del_event(ngx_event_t *ev, int event, u_int flags)
 {
+    int                  op, prev;
+    ngx_event_t         *e;
+    ngx_connection_t    *c;
     struct epoll_event   ee;
-    ngx_connection_t    *c;
+
+    /*
+     * when the file descriptor is closed the epoll automatically deletes
+     * it from its queue so we do not need to delete explicity the event
+     * before the closing the file descriptor.
+     */
+
+    if (flags & NGX_CLOSE_EVENT) {
+        ev->active = 0;
+        return NGX_OK;
+    }
 
     c = ev->data;
 
-    ee.events = 0;
-    ee.data.ptr = NULL;
+    if (event == NGX_READ_EVENT) {
+        e = c->write;
+        prev = EPOLLOUT;
+
+    } else {
+        e = c->read;
+        prev = EPOLLIN;
+    }
+
+    if (e->active) {
+        op = EPOLL_CTL_MOD;
+        ee.events = prev | flags;
+        ee.data.ptr = (void *) ((uintptr_t) c | ev->instance);
 
-    ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0,
-                   "epoll del event: fd:%d", c->fd);
+    } else {
+        op = EPOLL_CTL_DEL;
+        ee.events = 0;
+        ee.data.ptr = NULL;
+    }
 
-    if (epoll_ctl(ep, EPOLL_CTL_DEL, c->fd, &ee) == -1) {
-        ngx_log_error(NGX_LOG_ALERT, c->log, ngx_errno,
-                      "epoll_ctl(EPOLL_CTL_MOD, %d) failed", c->fd);
+    ngx_log_debug3(NGX_LOG_DEBUG_EVENT, ev->log, 0,
+                   "epoll del event: fd:%d op:%d ev:%08X",
+                   c->fd, op, ee.events);
+
+    if (epoll_ctl(ep, op, c->fd, &ee) == -1) {
+        ngx_log_error(NGX_LOG_ALERT, ev->log, ngx_errno,
+                      "epoll_ctl(%d, %d) failed", op, c->fd);
         return NGX_ERROR;
     }
 
@@ -248,6 +303,7 @@ static int ngx_epoll_del_event(ngx_event
 }
 
 
+#if 0
 static int ngx_epoll_add_connection(ngx_connection_t *c)
 {
     struct epoll_event  ee;
@@ -278,6 +334,7 @@ static int ngx_epoll_del_connection(ngx_
 
     return NGX_OK;
 }
+#endif
 
 
 int ngx_epoll_process_events(ngx_log_t *log)

--- a/src/event/modules/ngx_kqueue_module.c
+++ b/src/event/modules/ngx_kqueue_module.c
@@ -254,7 +254,7 @@ static int ngx_kqueue_del_event(ngx_even
     }
 
     /*
-     * when the file descriptor is closed a kqueue automatically deletes
+     * when the file descriptor is closed the kqueue automatically deletes
      * its filters so we do not need to delete explicity the event
      * before the closing the file descriptor.
      */

--- a/src/event/modules/ngx_poll_module.c
+++ b/src/event/modules/ngx_poll_module.c
@@ -146,7 +146,7 @@ static int ngx_poll_add_event(ngx_event_
 
     } else {
         ngx_log_debug1(NGX_LOG_DEBUG_EVENT, ev->log, 0,
-                       "poll index: %d", e->index);
+                       "poll add index: %d", e->index);
 
         event_list[e->index].events |= event;
         ev->index = e->index;
@@ -195,6 +195,10 @@ static int ngx_poll_del_event(ngx_event_
         nevents--;
 
         if (ev->index < (u_int) nevents) {
+
+            ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
+                           "index: copy event %d to %d", nevents, ev->index);
+
             event_list[ev->index] = event_list[nevents];
 
             c = &ngx_cycle->connections[event_list[nevents].fd];
@@ -219,20 +223,17 @@ static int ngx_poll_del_event(ngx_event_
             } else {
                 if (c->read->index == (u_int) nevents) {
                     c->read->index = ev->index;
-
-                } else if (c->write->index == (u_int) nevents) {
-                    c->write->index = ev->index;
+                }
 
-                } else {
-                    ngx_log_error(NGX_LOG_ALERT, ev->log, 0,
-                                  "unexpected last event index");
+                if (c->write->index == (u_int) nevents) {
+                    c->write->index = ev->index;
                 }
             }
         }
 
     } else {
         ngx_log_debug1(NGX_LOG_DEBUG_EVENT, ev->log, 0,
-                       "poll index: %d", e->index);
+                       "poll del index: %d", e->index);
 
         event_list[e->index].events &= ~event;
     }

--- a/src/event/ngx_event.h
+++ b/src/event/ngx_event.h
@@ -176,18 +176,19 @@ extern ngx_event_actions_t   ngx_event_a
 
 /*
  * The event filter requires to read/write the whole data -
- * select, poll, /dev/poll, kqueue.
+ * select, poll, /dev/poll, kqueue, epoll.
  */
 #define NGX_USE_LEVEL_EVENT    0x00000001
 
 /*
  * The event filter is deleted after a notification without an additional
- * syscall - select, poll, kqueue.
+ * syscall - select, poll, kqueue, epoll.
  */
 #define NGX_USE_ONESHOT_EVENT  0x00000002
 
 /*
- *  The event filter notifies only the changes and an initial level - kqueue.
+ * The event filter notifies only the changes and an initial level -
+ * kqueue, epoll.
  */
 #define NGX_USE_CLEAR_EVENT    0x00000004
 
@@ -205,7 +206,7 @@ extern ngx_event_actions_t   ngx_event_a
 
 /*
  * The event filter notifies only the changes (the edges)
- * but not an initial level - epoll.
+ * but not an initial level - early epoll patches.
  */
 #define NGX_USE_EDGE_EVENT     0x00000020
 
@@ -275,6 +276,27 @@ extern ngx_event_actions_t   ngx_event_a
 #define NGX_DISABLE_EVENT  EV_DISABLE
 
 
+#elif (HAVE_DEVPOLL)
+
+#define NGX_READ_EVENT     POLLIN
+#define NGX_WRITE_EVENT    POLLOUT
+
+#define NGX_LEVEL_EVENT    0
+
+
+#elif (HAVE_EPOLL)
+
+#define NGX_READ_EVENT     EPOLLIN
+#define NGX_WRITE_EVENT    EPOLLOUT
+
+#define NGX_LEVEL_EVENT    0
+#define NGX_CLEAR_EVENT    EPOLLET
+#define NGX_ONESHOT_EVENT  0x70000000
+#if 0
+#define NGX_ONESHOT_EVENT  EPOLLONESHOT
+#endif
+
+
 #elif (HAVE_POLL)
 
 #define NGX_READ_EVENT     POLLIN
@@ -284,14 +306,6 @@ extern ngx_event_actions_t   ngx_event_a
 #define NGX_ONESHOT_EVENT  1
 
 
-#elif (HAVE_DEVPOLL)
-
-#define NGX_READ_EVENT     POLLIN
-#define NGX_WRITE_EVENT    POLLOUT
-
-#define NGX_LEVEL_EVENT    0
-
-
 #else /* select */
 
 #define NGX_READ_EVENT     0

--- a/src/event/ngx_event_accept.c
+++ b/src/event/ngx_event_accept.c
@@ -142,7 +142,7 @@ void ngx_event_accept(ngx_event_t *ev)
             return;
         }
 
-        /* set a blocking mode for aio and non-blocking mode for others */
+        /* set a blocking mode for aio and non-blocking mode for the others */
 
         if (ngx_inherited_nonblocking) {
             if ((ngx_event_flags & NGX_USE_AIO_EVENT)) {

--- a/src/http/ngx_http_request.c
+++ b/src/http/ngx_http_request.c
@@ -84,10 +84,10 @@ void ngx_http_init_connection(ngx_connec
     rev = c->read;
     rev->event_handler = ngx_http_init_request;
 
-    /* STUB: epoll */ c->write->event_handler = ngx_http_empty_handler;
+    /* STUB: epoll edge */ c->write->event_handler = ngx_http_empty_handler;
 
     if (rev->ready) {
-        /* deferred accept, aio, iocp, epoll */
+        /* deferred accept, aio, iocp */
         ngx_http_init_request(rev);
         return;
     }
@@ -1180,6 +1180,8 @@ static void ngx_http_set_keepalive(ngx_h
     }
 
     h = c->buffer;
+    wev = c->write;
+    wev->event_handler = ngx_http_empty_handler;
 
     if (h->pos < h->last) {
 
@@ -1214,8 +1216,6 @@ static void ngx_http_set_keepalive(ngx_h
 
     h->pos = h->last = h->start;
     rev->event_handler = ngx_http_keepalive_handler;
-    wev = c->write;
-    wev->event_handler = ngx_http_empty_handler;
 
     if (wev->active) {
         if (ngx_event_flags & NGX_HAVE_KQUEUE_EVENT) {