diff --git a/src/sf_nio.c b/src/sf_nio.c
index 4f07210..9b04803 100644
--- a/src/sf_nio.c
+++ b/src/sf_nio.c
@@ -98,7 +98,7 @@ static inline int set_write_event(struct fast_task_info *task)
         task->event.fd, IOEVENT_WRITE, task) != 0)
     {
         result = errno != 0 ? errno : ENOENT;
-        SF_CTX->task_cleanup_func(task);
+        iovent_add_to_deleted_list(task);
 
         logError("file: "__FILE__", line: %d, "
             "ioevent_modify fail, "
@@ -122,7 +122,7 @@ static inline int set_read_event(struct fast_task_info *task)
                 task->event.fd, IOEVENT_READ, task) != 0)
     {
         result = errno != 0 ? errno : ENOENT;
-        SF_CTX->task_cleanup_func(task);
+        iovent_add_to_deleted_list(task);
 
         logError("file: "__FILE__", line: %d, "
                 "ioevent_modify fail, "
@@ -195,13 +195,12 @@ static int sf_nio_deal_task(struct fast_task_info *task)
     }
 
     if (result < 0) {
-        SF_CTX->task_cleanup_func(task);
+        iovent_add_to_deleted_list(task);
     }
 
     return result;
 }
 
-#if defined(OS_LINUX)
 int sf_nio_notify(struct fast_task_info *task, const int stage)
 {
     int64_t n;
@@ -262,59 +261,11 @@ void sf_recv_notify_read(int sock, short event, void *arg)
         task = current;
         current = current->next;
 
-        sf_nio_deal_task(task);
-    }
-}
-
-#else
-
-int sf_nio_notify(struct fast_task_info *task, const int stage)
-{
-    long task_addr;
-    int result;
-
-    task_addr = (long)task;
-    task->nio_stage = stage;
-    if (write(NOTIFY_WRITE_FD(task->thread_data), &task_addr,
-                sizeof(task_addr)) != sizeof(task_addr))
-    {
-        result = errno != 0 ? errno : EIO;
-        logError("file: "__FILE__", line: %d, "
-                "write to pipe %d fail, errno: %d, error info: %s",
-                __LINE__, NOTIFY_WRITE_FD(task->thread_data),
-                result, STRERROR(result));
-        return result;
-    }
-
-    return 0;
-}
-
-void sf_recv_notify_read(int sock, short event, void *arg)
-{
-    int bytes;
-    long task_ptr;
-    struct fast_task_info *task;
-
-    while (1) {
-        if ((bytes=read(sock, &task_ptr, sizeof(task_ptr))) < 0) {
-            if (!(errno == EAGAIN || errno == EWOULDBLOCK)) {
-                logError("file: "__FILE__", line: %d, "
-                        "call read failed, "
-                        "errno: %d, error info: %s",
-                        __LINE__, errno, strerror(errno));
-            }
-
-            break;
+        if (!task->canceled) {
+            sf_nio_deal_task(task);
         }
-        else if (bytes == 0) {
-            break;
-        }
-
-        task = (struct fast_task_info *)task_ptr;
-        sf_nio_deal_task(task);
     }
 }
-#endif
 
 int sf_send_add_event(struct fast_task_info *task)
 {
@@ -337,7 +288,7 @@ int sf_client_sock_read(int sock, short event, void *arg)
     struct fast_task_info *task;
 
     task = (struct fast_task_info *)arg;
-    if (task->nio_stage != SF_NIO_STAGE_RECV) {
+    if (task->canceled || (task->nio_stage != SF_NIO_STAGE_RECV)) {
         return 0;
     }
 
@@ -346,7 +297,7 @@ int sf_client_sock_read(int sock, short event, void *arg)
         if (task->offset == 0 && task->req_count > 0) {
             if (SF_CTX->timeout_callback != NULL) {
                 if (SF_CTX->timeout_callback(task) != 0) {
-                    SF_CTX->task_cleanup_func(task);
+                    iovent_add_to_deleted_list(task);
                     return -1;
                 }
             }
@@ -370,7 +321,7 @@ int sf_client_sock_read(int sock, short event, void *arg)
                         __LINE__, task->client_ip,  task->req_count);
             }
 
-            SF_CTX->task_cleanup_func(task);
+            iovent_add_to_deleted_list(task);
             return -1;
         }
 
@@ -382,7 +333,7 @@ int sf_client_sock_read(int sock, short event, void *arg)
             "client ip: %s, recv error event: %d, "
             "close connection", __LINE__, task->client_ip, event);
 
-        SF_CTX->task_cleanup_func(task);
+        iovent_add_to_deleted_list(task);
         return -1;
     }
 
@@ -416,7 +367,7 @@ int sf_client_sock_read(int sock, short event, void *arg)
                     __LINE__, task->client_ip,
                     errno, strerror(errno));
 
-                SF_CTX->task_cleanup_func(task);
+                iovent_add_to_deleted_list(task);
                 return -1;
             }
         }
@@ -445,7 +396,7 @@ int sf_client_sock_read(int sock, short event, void *arg)
                         __LINE__, task->client_ip, sock);
             }
 
-            SF_CTX->task_cleanup_func(task);
+            iovent_add_to_deleted_list(task);
             return -1;
         }
 
@@ -457,7 +408,7 @@ int sf_client_sock_read(int sock, short event, void *arg)
             }
 
             if (SF_CTX->set_body_length(task) != 0) {
-                SF_CTX->task_cleanup_func(task);
+                iovent_add_to_deleted_list(task);
                 return -1;
             }
             if (task->length < 0) {
@@ -466,7 +417,7 @@ int sf_client_sock_read(int sock, short event, void *arg)
                     __LINE__, task->client_ip,
                     task->length);
 
-                SF_CTX->task_cleanup_func(task);
+                iovent_add_to_deleted_list(task);
                 return -1;
             }
 
@@ -478,7 +429,7 @@ int sf_client_sock_read(int sock, short event, void *arg)
                     task->client_ip, task->length,
                     g_sf_global_vars.max_pkg_size);
 
-                SF_CTX->task_cleanup_func(task);
+                iovent_add_to_deleted_list(task);
                 return -1;
             }
 
@@ -491,7 +442,7 @@ int sf_client_sock_read(int sock, short event, void *arg)
                             "from %d to %d fail", __LINE__,
                             task->client_ip, task->size, task->length);
 
-                    SF_CTX->task_cleanup_func(task);
+                    iovent_add_to_deleted_list(task);
                     return -1;
                 }
 
@@ -506,7 +457,7 @@ int sf_client_sock_read(int sock, short event, void *arg)
             task->req_count++;
             task->nio_stage = SF_NIO_STAGE_SEND;
             if (SF_CTX->deal_task(task) < 0) {  //fatal error
-                SF_CTX->task_cleanup_func(task);
+                iovent_add_to_deleted_list(task);
                 return -1;
             }
             break;
@@ -524,13 +475,17 @@ int sf_client_sock_write(int sock, short event, void *arg)
 
     assert(sock >= 0);
     task = (struct fast_task_info *)arg;
+    if (task->canceled) {
+        return 0;
+    }
+
     if (event & IOEVENT_TIMEOUT) {
         logError("file: "__FILE__", line: %d, "
             "client ip: %s, send timeout. total length: %d, offset: %d, "
             "remain: %d", __LINE__, task->client_ip, task->length,
             task->offset, task->length - task->offset);
 
-        SF_CTX->task_cleanup_func(task);
+        iovent_add_to_deleted_list(task);
         return -1;
     }
 
@@ -539,7 +494,7 @@ int sf_client_sock_write(int sock, short event, void *arg)
             "client ip: %s, recv error event: %d, "
             "close connection", __LINE__, task->client_ip, event);
 
-        SF_CTX->task_cleanup_func(task);
+        iovent_add_to_deleted_list(task);
         return -1;
     }
 
@@ -572,7 +527,7 @@ int sf_client_sock_write(int sock, short event, void *arg)
                     __LINE__, task->client_ip,
                     errno, strerror(errno));
 
-                SF_CTX->task_cleanup_func(task);
+                iovent_add_to_deleted_list(task);
                 return -1;
             }
         }
@@ -582,7 +537,7 @@ int sf_client_sock_write(int sock, short event, void *arg)
                 "connection disconnected",
                 __LINE__, task->client_ip, sock);
 
-            SF_CTX->task_cleanup_func(task);
+            iovent_add_to_deleted_list(task);
             return -1;
         }
 
@@ -601,4 +556,3 @@ int sf_client_sock_write(int sock, short event, void *arg)
 
     return total_write;
 }
-
diff --git a/src/sf_service.c b/src/sf_service.c
index 4569cdd..9430776 100644
--- a/src/sf_service.c
+++ b/src/sf_service.c
@@ -176,6 +176,9 @@ int sf_service_init_ex(SFContext *sf_context,
             return result;
         }
 
+        if ((result=init_pthread_lock(&thread_data->waiting_queue.lock)) != 0) {
+            return result;
+        }
 #if defined(OS_LINUX)
         NOTIFY_READ_FD(thread_data) = eventfd(0, EFD_NONBLOCK);
         if (NOTIFY_READ_FD(thread_data) < 0) {
@@ -187,10 +190,6 @@ int sf_service_init_ex(SFContext *sf_context,
             break;
         }
         NOTIFY_WRITE_FD(thread_data) = NOTIFY_READ_FD(thread_data);
-
-        if ((result=init_pthread_lock(&thread_data->waiting_queue.lock)) != 0) {
-            return result;
-        }
 #else
         if (pipe(thread_data->pipe_fds) != 0) {
             result = errno != 0 ? errno : EPERM;
@@ -355,6 +354,7 @@ static void *accept_thread_entrance(void *arg)
         }
         strcpy(task->client_ip, szClientIp);
 
+        task->canceled = false;
         task->ctx = accept_context->sf_context;
         task->event.fd = incomesock;
         task->thread_data = accept_context->sf_context->thread_data +