| 摘要 |
PROBLEM TO BE SOLVED: To reduce task switching frequency, and to reduce the generation of dead line violation in a real time OS for scheduling a fixed cycle task to be repeatedly executed in each fixed time interval. SOLUTION: A start task deciding part 11 is newly provided with a task start excess time comparing means 16. Whether or not the start of the execution of a task whose execution priority index is large can be delayed is judged by the task start excess time comparing means 16 without unconditionally switching a task even when a task whose priority index is large is requested, and when it is possible, the execution of the task whose execution priority index is small which is being executed at present is continued, and the early end of the task whose priority index is small is realized. Thus, it is possible to reduce the number of times of task switching being the factor of the generation of the overhead of the executing time, and to reduce dead line violation which is likely to be generated in the task whose priority index is small.
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