diff --git a/HISTORY b/HISTORY
index e8a0df18ddd8f26ec11dc445a70fcef6384ff872..585348b8434a349f774cd08a40feef5fe620942f 100644
--- a/HISTORY
+++ b/HISTORY
@@ -1,5 +1,5 @@
 
-Version 1.44  2020-10-21
+Version 1.44  2020-10-28
   * add test file src/tests/test_pthread_lock.c
   * add uniq_skiplist.[hc]
   * add function split_string_ex
diff --git a/src/fast_task_queue.h b/src/fast_task_queue.h
index 37a02f1651c711de2125961cf16429cb09f794b0..5e2d4c34ba76ff03b54cf8fd9dd14e87b55bf88c 100644
--- a/src/fast_task_queue.h
+++ b/src/fast_task_queue.h
@@ -87,7 +87,9 @@ struct fast_task_info
         uint8_t current;
         volatile uint8_t notify;
     } nio_stages; //stages for network IO
-    bool canceled;   //if task canceled
+    int (*continue_callback)(struct fast_task_info *task);  //for continue stage
+    volatile int8_t reffer_count;
+    volatile int8_t canceled;   //if task canceled
     int connect_timeout; //for client side
     int network_timeout;
 	int64_t req_count; //request count
diff --git a/src/ioevent_loop.h b/src/ioevent_loop.h
index 40a5946523e4815f675d234b65dc20a0414047c3..8a419706fa5c9de11c50815d1d426928b038485e 100644
--- a/src/ioevent_loop.h
+++ b/src/ioevent_loop.h
@@ -32,20 +32,16 @@ int ioevent_remove(IOEventPoller *ioevent, void *data);
 int ioevent_set(struct fast_task_info *pTask, struct nio_thread_data *pThread,
 	int sock, short event, IOEventCallback callback, const int timeout);
 
+//only called by the nio thread
 static inline void ioevent_add_to_deleted_list(struct fast_task_info *task)
 {
-    if (task->thread_data == NULL)
+    if (!__sync_bool_compare_and_swap(&task->canceled, 0, 1))
     {
-        return;
-    }
-
-    if (task->canceled) {
-        logError("file: "__FILE__", line: %d, "
+        logWarning("file: "__FILE__", line: %d, "
                 "task %p already canceled", __LINE__, task);
         return;
     }
 
-    task->canceled = true;
     task->next = task->thread_data->deleted_list;
     task->thread_data->deleted_list = task;
 }