1. A method, comprising: in response to a user event received for a target element in a webpage, the webpage being received and currently rendered for display by a device, the device being provided with a browser engine configured with a default handling action for the received user event, concurrently dispatching the user event for processing in a main thread and a secondary thread; processing the user event in the main thread using an event handler associated with said target element and received with the webpage by the device; processing the user event in the secondary thread using the default handling action at least partially concurrently with the processing of the user event in the main thread; while the processing of the user event in the main thread and the processing of the user event in the secondary thread are executing concurrently, the main thread determining that the default handling action is to be prevented for the user event; the main thread notifying the secondary thread to terminate; and updating the current rendering of the webpage according to the processing completed by that first one of the main thread.