Embedded real-time scheduling method based on fuzzy multiple features of task

Abstract

The invention discloses an embedded real-time scheduling method based on fuzzy multiple features of a task. Through initialization and the adjustment of a task scheduling priority, a task with a highest scheduling priority is selected to run according to a corresponding policy so as to carry out task scheduling, and compared with a conventional drive method of a shortest deadline distance, the method can realize a quite low deadline miss ratio and is particularly suitable for the existing embedded communication equipment. Compared with conventional embedded real-time system scheduling, the invention not only considers the factor of the multiple features of the task, but also adapts to the characteristic of uncertain running environment of communication network application by a fuzzy method. The method considers guaranteeing an important task to be preferentially run as far as possible so as to reduce the probability of missing a deadline and also considers that when the deadline of a general task is closer, the general task is put into run as soon as possible so as to improve the utilization rate of the whole system.

Description

technical field [0001] The invention relates to the computer field, in particular to an embedded real-time scheduling method based on task fuzzy multi-features. Background technique [0002] The embedded real-time system is the most important application and research direction in the computer field at present. The main features of the system are: 1. The tasks in the system are generally periodic tasks, that is, the tasks are executed repeatedly at fixed time intervals; 2. Task scheduling The mechanism is usually based on priority-driven, that is, tasks with high priority are run first; 3. Each periodic task often corresponds to a deadline, and the system should try its best to satisfy important tasks before the deadline arrives. The scheduled real-time tasks embedded in the real-time system can be formally described as: [0003] τ i =(S i , C i ,D i ,T i ), 0<C i ≤D i , 0<P i , 0≤S i [0004] Among them, S i is the arrival time of the task; C i is the wors...

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Problems solved by technology

[0036] 2) The determination of the scheduling priority is based on the precise value of the task characteristics, but in fact, due to the instability of the system operating environment (such as the network communication application environment), it is difficult to obtain the accuracy of the task characteristics, and it is not very consistent. The actual situation of the operating environment, so it is not suitable to describe with precise values

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