Research On Mechanism Of Thread Ofμ-Kernel Operating System VTOS

Operating system is one of the basic software systems, and its reliability, security, and performance play a vital role in the operation of the whole computer system.Monolithic kernel and micro kernel are two common architectures in the construction of an operating system. Compared with the operating system using monolithic kernel architecture, the operating system using micro kernel architecture has many distinguished characteristics:smaller kernel, system services are provided by some user-mode programs, policies are independent with mechanisms, faults in one service will not affect the other services. But the amount of switch between different address spaces in micro kernel operating system is more often than that in monolithic kernel operating system, which leads to the overhead of performance.With the multi-core processor becomes more and more prevalent, many researchers are dedicated to the study of mechanism of multi-threading, because a program with multiple threads can use the underlying processor to commit tasks in parallel, so as to improve the performance of the program itself.VTOS system is an operating system, whose architecture is micro-kernel, is developed on the base of Minix3.1.1. VTOS’s micro-kernel architecture can ensure the reliability and security. But its kernel cannot support the kernel level thread mechanism, and that is a short from the aspect of function and performance.This paper analyzed the corresponding design and implementation of Mach and L4systems, and designed and implemented the kernel level thread mechanism and user level thread library for VTOS. And our research includes the following perspectives:1. The architecture and structure of VTOS kernel level thread. Policies are separated with mechanism as much as possible, so as to improve the flexibility and extensibility.2. Describe the design with the method of object model, and propose some attributes about the security of the system.3. We reduce the amount of switch between different address spaces with the help of a novel algorithm of kernel level thread schedule.4. Provide a user level thread library to implement the one-to-one thread mode.