VxWorks中任务恢复机制的设计与实现

软件容错技术是保证系统高可靠性及高可信性的有力工具。设计并实现了一种在VxWorks系统下基于检查点的任务恢复机制。通过对VxWorks系统下检查点文件内容的分析,采用3种方法来解决检查点的任务恢复问题:基于内存预先分配的主动内存管理,解决任务恢复时数据内存地址变化的问题;建立系统内核对象池,实现支持多任务之间同步和通信的内核对象的恢复;设计用户层任务恢复中间件,实现用户级检查点设置和任务恢复。最后设计基于VxWorks和PowerPC的计算平台原理样机,通过对单任务、多个单任务、多任务通讯、以及多任务协调工作4个测试用例的分析表明,所设计的基于检查点的任务恢复实现方案能正确保存任务关键信息及保证任务恢复的正确性和一致性。

Design and Implementation of the Checkpointing and Task Recovery Mechanism Based on VxWorks

Software fault tolerant technique is a means used to guarantee the high reliability and high credibility in systems. This paper proposes a checkpointing-based task recovery mechanism on the VxWorks operating system. Three methods are adopted to solve the checkpointing-based task recovery problem through analyzing the contents of checkpoint files in VxWorks: the variation of memory address is solved based on the active management of pre-allocated memory; the system kernel object pools are built to realize the recovery of kernel object supporting the synchronization and communication between multi tasks; and the task recovery middleware in user layer is designed to achieve the checkpointing setup and task recovery. Finally, the prototype system based on VxWorks and PowerPC is designed and the results show that the use of the checkpointing-based task recovery mechanism can save the task key information correctly and guarantee the validity and consistency of the task recovery.