The Embedded Real-time Process Management And Its Support For Real-time Databases

ARTs-OS is an embedded real-time operating system developed by Huaxiang Software Research and Development Centre, and process management module is the key module in it, which decides whether embedded real-time database ARTs-EDB is embedded, real-time and data integral, or not.The real-time process module includes two parts, one is dynamically extensible integrated micro-kernel, and another is multi-process and multi-thread out of kernel. The former, which includes only the basic functions of the kernel and can be extended statically or dynamically, has no kernel thread, so it is small, integrated, extensible and high concurrent. The latter, which considers both the function efficiency of the multi-thread and the protection of the multi-process, supports the nested transaction model in ARTs-EDB perfectly.The priority-driven preemptable scheduling module in ARTs-OS, which is responsible for choosing the thread with highest priority to get CPU, is the foundation of transaction scheduling in ARTs-EDB. It is low system spending, predictable, and high efficient. In addition, to support the committing rule and the abortion rule of ARTs-EDB, ARTs-OS introduces the concept of the committing exit and abortion exit of the thread, which is the original creation in ARTs-OS.The optional task accepting control module in ARTs-OS has two functions, one is task priority allocation, another is task set schedulability analysis. The task priority allocation adopts Deffeded Rate Monotonic (DRM) priority allocation algorithm for hybrid real-time tasks, which has improved the shedulability of the task set submitted to ARTs-OS.The test of the performance of the process management module shows that the time precision of ARTs-OS is on microsecond level, which has met the system requirements.