diff --git a/components/esp8266/include/esp_socket.h b/components/esp8266/include/esp_socket.h
index 4ebc6971..5b5ee1f4 100644
--- a/components/esp8266/include/esp_socket.h
+++ b/components/esp8266/include/esp_socket.h
@@ -137,6 +137,36 @@ typedef struct esp_socket_method {
     int (*close)(void *index);
 } esp_socket_method_t;
 
+/*
+ * @brief free an aio control block by calling the callback function
+ * 
+ * @param aio asynchronous I/O controlling block
+ * @param aio data handling result
+ * 
+ * @return none
+ */
+static inline void esp_aio_free(esp_aio_t *aio, int status)
+{
+    if (aio->cb) {
+        aio->ret = status;
+        aio->cb(aio);
+    }
+}
+
+/*
+ * @brief drop an aio control block by disable "pbuf" and "cb"
+ *        and then the aio control block has no meaning
+ * 
+ * @param aio asynchronous I/O controlling block
+ * 
+ * @return none
+ */
+static inline void esp_aio_drop(esp_aio_t *aio)
+{
+    aio->pbuf = NULL;
+    aio->cb = NULL;
+}
+
 /*
  * @brief create a socket file description
  *
diff --git a/components/esp8266/source/esp_socket.c b/components/esp8266/source/esp_socket.c
index 6c025be0..74d2def5 100644
--- a/components/esp8266/source/esp_socket.c
+++ b/components/esp8266/source/esp_socket.c
@@ -25,7 +25,7 @@
 #define CRITICAL_EXIT(t)
 
 #ifndef ESP_SOCKET_MAX
-#define ESP_SOCKET_MAX 3
+#define ESP_SOCKET_MAX 2
 #endif
 
 #define SET_ERR(err)                    errno = err