add close xio api

inc/azure_umqtt_c/mqtt_client.h

@@ -48,6 +48,7 @@ typedef void(*ON_MQTT_ERROR_CALLBACK)(MQTT_CLIENT_HANDLE handle, MQTT_CLIENT_EVE
 typedef void(*ON_MQTT_MESSAGE_RECV_CALLBACK)(MQTT_MESSAGE_HANDLE msgHandle, void* callbackCtx);
 typedef void(*ON_MQTT_DISCONNECTED_CALLBACK)(void* callbackCtx);
 
+MOCKABLE_FUNCTION(, void, mqtt_client_close_xio, MQTT_CLIENT_HANDLE, mqtt_client);
 MOCKABLE_FUNCTION(, MQTT_CLIENT_HANDLE, mqtt_client_init, ON_MQTT_MESSAGE_RECV_CALLBACK, msgRecv, ON_MQTT_OPERATION_CALLBACK, opCallback, void*, opCallbackCtx, ON_MQTT_ERROR_CALLBACK, onErrorCallBack, void*, errorCBCtx);
 MOCKABLE_FUNCTION(, void, mqtt_client_deinit, MQTT_CLIENT_HANDLE, handle);
 

src/mqtt_client.c

@@ -945,6 +945,14 @@ static void recvCompleteCallback(void* context, CONTROL_PACKET_TYPE packet, int
     }
 }
 
+void mqtt_client_close_xio(MQTT_CLIENT_HANDLE handle)
+{
+  MQTT_CLIENT* mqtt_client = (MQTT_CLIENT*)handle;
+  (void)xio_close(mqtt_client->xioHandle, on_connection_closed, mqtt_client);
+  // Clear the handle because we don't use it anymore
+  mqtt_client->xioHandle = NULL;
+}
+
 MQTT_CLIENT_HANDLE mqtt_client_init(ON_MQTT_MESSAGE_RECV_CALLBACK msgRecv, ON_MQTT_OPERATION_CALLBACK operation_cb, void* opCallbackCtx, ON_MQTT_ERROR_CALLBACK onErrorCallBack, void* errorCBCtx)
 {
     MQTT_CLIENT* result;