Multi-task scheduling method applicable to embedded software systems

Abstract

The invention discloses a multi-task scheduling method applicable to embedded software systems. The multi-task scheduling method includes that S1, two-dimensional task queues with one-dimensional priority node arrays are set; S2, the one-dimensional priority node arrays are of array structures, task linked lists are of linked list structures, and task linked list nodes contain two types of elements for representing current task priority data and pointing to next linked list node data; S3, the two-dimensional task queues are initialized, priority node values are null if ready tasks with corresponding priority are unavailable, and priority nodes point to ready task linked lists with equal priority if the ready tasks are available; S4, the priority node arrays are searched according to priority sequences from high to low when the two-dimensional task queues are completely initialized, and the tasks which are pointed by the first not-null priority nodes are started; S5, the tasks are suspended at the tails of the certain ready task linked lists according to the priority of the tasks when the tasks are ready, and the certain ready task linked lists are pointed by the corresponding priority nodes. The multi-task scheduling method has the advantages of easiness in implementation and low overhead.

Description

technical field [0001] The invention relates to a multi-task scheduling method for a software system, in particular to a multi-task scheduling method suitable for an embedded software system. Background technique [0002] Realizing multi-task scheduling based on embedded operating system is a method used by many large-scale embedded software systems. The scheduling method of embedded operating system has the advantages of reasonableness, optimization, powerful functions, and no need for designers to compile scheduling algorithms. However, the shortcomings are the disadvantages of large overhead (large memory occupation), long start-up time, and large capital investment, so it often cannot meet the development needs of small and medium-sized embedded software systems. For embedded software systems without an operating system, the multi-task scheduling is generally implemented by interrupts. This method has the advantages of simple structure and timely response, but the disadv...

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Problems solved by technology

However, the shortcomings are the disadvantages of large overhead (large memory usage), long startup time, and large capital investment, so it often cannot meet the development needs of small and medium-sized embedded software systems.

For embedded software systems without an operating system, the multi-task scheduling is generally implemented by interrupts. This method has the advantages of simple structure and timely response, but the disadvantage is that the number of tasks is limited by the number of interrupts, and the length of tasks is limited. interruption time

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