diff --git a/src/sf_nio.c b/src/sf_nio.c
index d87bfb2..8a820b6 100644
--- a/src/sf_nio.c
+++ b/src/sf_nio.c
@@ -143,7 +143,6 @@ static inline int set_read_event(struct fast_task_info *task)
 {
     int result;
 
-    task->nio_stages.current = SF_NIO_STAGE_RECV;
     if (task->event.callback == (IOEventCallback)sf_client_sock_read) {
         return 0;
     }
@@ -169,6 +168,7 @@ int sf_set_read_event(struct fast_task_info *task)
 {
     task->recv.ptr->offset = 0;
     task->recv.ptr->length = 0;
+    task->nio_stages.current = SF_NIO_STAGE_RECV;
     return set_read_event(task);
 }
 
@@ -321,6 +321,7 @@ static int sf_nio_deal_task(struct fast_task_info *task, const int stage)
             result = sf_async_connect_server(task);
             break;
         case SF_NIO_STAGE_RECV:
+            task->nio_stages.current = SF_NIO_STAGE_RECV;
             if ((result=set_read_event(task)) == 0) {
                 if (sf_client_sock_read(task->event.fd,
                             IOEVENT_READ, task) < 0)
@@ -544,10 +545,10 @@ static inline int check_task(struct fast_task_info *task,
     }
 }
 
-ssize_t sf_socket_send_data(struct fast_task_info *task, SFCommAction *action)
+ssize_t sf_socket_send_data(struct fast_task_info *task,
+        SFCommAction *action, bool *send_done)
 {
     int bytes;
-    int length;
 
     if (task->iovec_array.iovs != NULL) {
         bytes = writev(task->event.fd, task->iovec_array.iovs,
@@ -590,19 +591,15 @@ ssize_t sf_socket_send_data(struct fast_task_info *task, SFCommAction *action)
 
     task->send.ptr->offset += bytes;
     if (task->send.ptr->offset >= task->send.ptr->length) {
-        length = task->send.ptr->length;
         if (task->send.ptr != task->recv.ptr) {  //double buffers
             task->send.ptr->offset = 0;
             task->send.ptr->length = 0;
         }
-        if (SF_CTX->callbacks.send_done != NULL) {
-            if (SF_CTX->callbacks.send_done(task, length) != 0) {
-                return -1;
-            }
-        }
         *action = sf_comm_action_finish;
+        *send_done = true;
     } else {
         *action = sf_comm_action_continue;
+        *send_done = false;
 
         /* set next writev iovec array */
         if (task->iovec_array.iovs != NULL) {
@@ -990,7 +987,10 @@ int sf_client_sock_write(int sock, short event, void *arg)
     int result;
     int bytes;
     int total_write;
+    int length;
+    int next_stage;
     SFCommAction action;
+    bool send_done;
     struct fast_task_info *task;
 
     task = (struct fast_task_info *)arg;
@@ -1010,13 +1010,14 @@ int sf_client_sock_write(int sock, short event, void *arg)
     }
 
     total_write = 0;
+    length = task->send.ptr->length;
     action = sf_comm_action_continue;
     while (1) {
         fast_timer_modify(&task->thread_data->timer,
                 &task->event.timer, g_current_time +
                 task->network_timeout);
 
-        if ((bytes=task->handler->send_data(task, &action)) < 0) {
+        if ((bytes=task->handler->send_data(task, &action, &send_done)) < 0) {
             ioevent_add_to_deleted_list(task);
             return -1;
         }
@@ -1024,10 +1025,26 @@ int sf_client_sock_write(int sock, short event, void *arg)
         total_write += bytes;
         if (action == sf_comm_action_finish) {
             release_iovec_buffer(task);
-            if (sf_set_read_event(task) != 0) {
+            task->recv.ptr->offset = 0;
+            task->recv.ptr->length = 0;
+            if (set_read_event(task) != 0) {
                 return -1;
             }
 
+            if (SF_CTX->callbacks.send_done == NULL || !send_done) {
+                task->nio_stages.current = SF_NIO_STAGE_RECV;
+            } else {
+                if (SF_CTX->callbacks.send_done(task,
+                            length, &next_stage) != 0)
+                {
+                    return -1;
+                }
+
+                if (task->nio_stages.current != next_stage) {
+                    task->nio_stages.current = next_stage;
+                }
+            }
+
             break;
         } else if (action == sf_comm_action_break) {
             break;
diff --git a/src/sf_nio.h b/src/sf_nio.h
index 14a80f5..1841429 100644
--- a/src/sf_nio.h
+++ b/src/sf_nio.h
@@ -143,7 +143,8 @@ static inline int sf_set_body_length(struct fast_task_info *task)
 int sf_socket_async_connect_server(struct fast_task_info *task);
 int sf_socket_async_connect_check(struct fast_task_info *task);
 
-ssize_t sf_socket_send_data(struct fast_task_info *task, SFCommAction *action);
+ssize_t sf_socket_send_data(struct fast_task_info *task,
+        SFCommAction *action, bool *send_done);
 ssize_t sf_socket_recv_data(struct fast_task_info *task,
         const bool call_post_recv, SFCommAction *action);
 
diff --git a/src/sf_types.h b/src/sf_types.h
index ef52625..f3c77d2 100644
--- a/src/sf_types.h
+++ b/src/sf_types.h
@@ -46,7 +46,7 @@ typedef char *(*sf_alloc_recv_buffer_callback)(struct fast_task_info *task,
 typedef int (*sf_deal_task_callback)(struct fast_task_info *task, const int stage);
 typedef int (*sf_recv_timeout_callback)(struct fast_task_info *task);
 typedef int (*sf_send_done_callback)(struct fast_task_info *task,
-        const int length);
+        const int length, int *next_stage);
 typedef void (*sf_connect_done_callback)(struct fast_task_info *task,
         const int err_no);
 
@@ -79,7 +79,7 @@ typedef int (*sf_async_connect_check_callback)(struct fast_task_info *task);
 typedef void (*sf_close_connection_callback)(struct fast_task_info *task);
 
 typedef ssize_t (*sf_send_data_callback)(struct fast_task_info *task,
-        SFCommAction *action);
+        SFCommAction *action, bool *send_done);
 typedef ssize_t (*sf_recv_data_callback)(struct fast_task_info *task,
         const bool call_post_recv, SFCommAction *action);
 typedef int (*sf_post_recv_callback)(struct fast_task_info *task);