The Research On Non-Blocking Synchronization Mechanism In The Embedded Operating System

Traditional blocking synchronization easily leads to process deadlock and priority inversion, which affects the real-time and stability of operating system. The more complexity of embedded system, the higher real-time and stable property of embedded system is required. Non-blocking synchronization mechanism is a new synchronization mechanism that can avoid process deadlock and priority inversion, which can make operating system more stable and improve real-time performace. Therefore, the article presents a new idea of applying non-blocking synchronization to embedded operating system.Firstly, the paper studies the implementation of non-blocking synchronization, summarizes the application principle of lock-free synchronization and wait-free synchronization in general operating system kernel, which guides the application of non-blocking synchronization in embedded operating system. Secondly, the paper analyzes the problems that lock-free synchronization and wait-free synchronization will face when they applied to embedded linux and then the according resolvent is put forwards in which the primary work is to improve old lock-free synchronization algorithm and priority inheritance algorithm in wait-free synchronization algorithm. Thirdly, regarding Montavista Linux as application platform, the paper implements CAS instruction which is the atomic memory modification operation of lock-free synchronization algorithm by embedded assemble language of powerpc, studies detailed algorithm of type-table memory management and implements an improved lock-free synchronization algorithm and an simpler wait-free synchronization algorithm.At last, we verify the correctness and validity of non-blocking synchronization that is implemented in embedded operating system in terms of synchronization overheads and real-time performance. The test results show that the performance of lock-free synchronization is better than that of traditional blocking synchronization, and although the performance of wait-free synchronization is little worse than that of thaditional blocking synchronization, wait-free synchronization completely avoids priority inversion and makes embedded operating system more stable. Therefore, the conclusion is that total performance of non-blocking synchronization is better than that of traditional blocking synchronization in embedded operating system.