Research On Hard Real-time Programming Model And Development Framework Based On Logical Execution Time

Real-time application is one of the broadest research subjects in computer application, and quite a large quantity of the microprocessors are consumed in the world by this kind of application. Hard real-time application is one of its important branches, whose context cover manufacturing, national defense and even the facilities in everyday life. However, the programming for such applications is not as productive as it should be, and the present design method cannot match well with the complexity and variety of the system.Along with the development of hard real-time application, it is important to choose an appropriate model that is easily implemented and verified. After being compared with several programming model, logical execution time (LET) is considered as a better one that is fit for the development of complex hard real time application.This thesis designs a language, TSL, and proposes a hard real-time framework, HARTIF, which supports real-time programming based on LET and Software Architecture. TSL is designed as a kind of Architecture Description Language, which describes the components and topology of the system, thus enabling programming in the large grain. Meanwhile, TSL also specifies the logical execution time of the components and assume their LET runtime semantics. In a word, TSL describes both the static and dynamic aspects of the target system.The HARTIF framework consists of three tools, Compiler for TSL language, Binder for binding individual software component and Checker for system safety. TSL is transformed by Compiler into virtual instructions, which is platform-independent, and then the instructions will be interpreted in real time with external functionality codes being invoked.This thesis will expatiated on the TSL language, virtual instruction and the HARTIF's Compiler tool, and another two tools of HARTIF also will be discussed.In addition, the case of "the elevator system" is studied based on HARTIF to show that resulting code can be easily structured, extended, and analyzed.