摘要 |
A view system is provided for each application program in a computer system in order to display application-generated information on a display. To increase graphic speed, the view system transfers graphic information directly into the screen buffer into a screen buffer area defined by a visible area definition. In order to handle concurrently-operating view systems, each of which modifies the displayed contents of one of the multiple views, a concurrency control controls access to the visible area definitions. The concurrency control is also used to control access to update requests which are generated when a change to one view affects other views. This mechanism supports animation, tracking feedback and updating invalid areas of the display by multiple threads of execution. This mechanism also provides a framework to support unrelated threads drawing in separate views within a single window. |