Several Methods of Design and Implementation to Solve Priority Inversion Problem in uC/OS-II

摘要

Multi-task concurrent execution and resource sharing based on preemptive scheduling strategy may cause priority inversion phenomenon in real-time systems. Priority inversion phenomenon is the significant reason of unpredictable errors in real-time system; serious continuous priority inversion phenomenon will lead to real-time system collapse. The paper analyzes the phenomenon and the cause of the phenomenon, puts forward several design and implementation methods to solve priority inversion problem suitable for various application scenarios in μC/OS-II. A priority exchange method is proposed to improve priority inheritance protocol. The proposed method limit priority inversion phenomenon to one level. Theoretical analyses and experimental results indicate that the methods to solve the priority inversion problem in μC/OS-II are concise and effective, provides reasonable technical means for the safe running of complex real-time applications in μC/OS-II.