Virtual Threads Architecture Basd On Network Gateway Operating System

Multithreading technology is an essential capability of modern operating systems. As an operating system based on network computing environments, NCOS (Network Coordinated Operating System) is dedicated to the construction of an improved operating system with high flexibility and robustness. However, one important thing is neglected: the consideration of an efficient multithreading system that is suitable for network gateway platform.Virtual Threads Architecture (VTS) is introduced to solve this problem. VTS is a multithreading system designed to work on specialized operating systems of network gateways. It abstracts the thread scheduling mechanism by utilizing virtual interface to map between virtual threads and real kernel scheduling entities. Thus it comes with the features of scalability and portability without losing its performance. Also it can be adapted to various platforms. Compared with the LinuxThreads library, VTS is more efficient and flexible, and can be used to fulfill the critic computing environments such as network coordinated computing or secure network gateway platforms.An intensive analysis of current LinuxThreads library is performed to deduce the theory of multithreading mechanism. Based on the analysis, flaws of LinuxThreads are revealed, such as the complicated and low efficient architecture, high overload of system resources, failure to keep compatible with POSIX standard, etc. After this, the conception of Virtual Threads Architecture is proposed.In the consequent chapters, various components of Virtual Threads Architecture are described in details, including its overall structure, virtual threading abstract, core scheduling algorithm, virtual threads interface, threads synchronizing and mutual excluding, and virtual threads signaling, as well as the internal details of each component. A functional prototype of VTS is produced based on the NCOS operating system. The core of VTS is the virtual thread scheduler. The internals and implementation of the virtual thread scheduler are described. Key technologies are analyzed and implimented, including the creating of threads, thread scheduling, and thread mutual excluding. Testing results are provided. An implementation of VTS prototype is tested against the LinuxThreads library based on the NCOS operating system. According to the testing results, by adoption of VTS system, the creation time of large number of threads is far shorter than that of LinuxThreads. Threads' creating speed is at least 2 times same as LinuxThreads library. The testing results proved that VTS is feasible and of better performance.