Windows NT-Based Realization Of Soft Real-Time Multitask

The applications of real-time system are very popular in modern industrial process, for example, the monitor and management of power system, the flight control of spacecraft, the robot control and the field of force and so on. The complication of industrial production result in complicated real-time system, so in design real-time system, we must carefully analyze the objects, which are controlled by real-time system, otherwise we will not design a successful real-time system. In our real-time system, it's application is related to the complicated craft of converter, the communication between different systems, database and computer network and so on.There are two different real-time systems: hard real-time system and soft real-time system. The requirement of hard real-tune system is very strict demand for time and there is not any response delay allowed, otherwise it will bring out a serious sequent. Generally, the real-time operation system realize the real-time system. The soft real-time system hasn't a strict demand for the tune and it asks for system scarcely to bring out a response delay. The response delay of soft real-time system doesn't come about a serious consequence. In general, the soft real-time system is realized by common operation system, such as Windows, Unix and Open VMS etc.The realization of our soft real-time system base on Windows NT and it is realized by the multitask emptive mechanism of NT. I firstly study the real-time quality of Windows NT and the possibility of Windows NT 's realization of real-time system before I realize the real-time system. I find out that Windows NT isn't a hard real-time operation system and it is only a soft real-time operation system, so the real-time system based on Windows NT is completely feasible and the applications of projects also support it's feasibility. Secondly, I study the real-tune quality of Ethernet and find out the Ethernet isn't a real-time network. Although real-time networks has a high real-time quality, it's stability is worse than Ethernet's. We buy better networks' hardware and lessen the period of communication, so we needn't to improve the protocol of Ethernet. Windows NT is very compatible for the Sql Server 2000,so the database has a very good stability. Thirdly, I design the database and optimize the database, because the design and optimization are very important for quality of system. In my thesis, I concentrate the database logical design and physical design. At last, I analyze the objects and functionsof real-time system and demarcate the tasks by focus of time and focus of function, which is very crucial for quality of real-time system. The time analysis is the premise of schedule algorithm's realization .if the time analysis isn't accuracy and the tasks will not get immediate response, which make the tasks lose the data and maybe bring about a serious consequence. I propose a real-time emptive scheduling algorithm based on multiprocessor and realize the dynamic and static algorithm after analyzing time and function of tasks.