Picture draw command scheduling in multitasking data processing apparatus.

摘要

The time taken from the generation of an H/W event made by a mouse or a keyboard to the picture drawing process to be performed in accordance with the event is shorted so as to provide a data processing apparatus which can be easily used by an operator because excellent real time characteristics is realized. The data processing apparatus has a host processor which logically constitutes a multitask device for executing a plurality of processes in a time sharing manner, an event notifying device for notifying generation of a hardware event to a corresponding process of a plurality of the processes, and a scheduling device for scheduling a picture draw request supplied from a plurality of the processes to a graphic device so as to form a single series for each picture draw request, and a graphic device processor for controlling the graphic device in accordance with a picture draw command in a predetermined unit transferred from a single series of the scheduling device so as to draw a picture, wherein the event notifying device monitors a state where the picture draw command in a predetermined unit is executed by the graphic device and notifies the event to a corresponding process after the event notifying device has compressed the event if the state of execution exceeds a predetermined degree.