Determining whether to execute a new task by deleting task objects of existing tasks

摘要

It is possible to simultaneously obtain a task delay guarantee and an effective task execution. Each of tasks (A1, A2, A3) is divided into a guaranteed portion and a controllable portion. The controllable portion is handled as a portion which can be deleted. While virtually changing the processing level of the reserved tasks (A1, A2) between the case not containing any controllable portion and the case containing a controllable portion, it is judged whether a task (A3) newly requested for reservation can be executed and at the processing level when the execution is judged to be possible, tasks (A1, A2, A3) to be executed are selected. By adjusting the quality of the reserved tasks (A1, A2), it is possible to accept and execute the task (A3) newly requested for reservation. Thus, it is possible to simultaneously obtain the task delay guarantee and the effective task execution.