多线程控制技术在面向对象实时仿真中的应用

随着实时仿真复杂性的提高,单个的处理器不足以完成所有的必需仿真计算任务。希望能在不同的处理器上完成实时仿真的不同任务,对称多处理器的机制需要软件支持,以使每个处理器通过共享内存进行信息交换。利用多线程控制技术,可以在非全进程开销或不使用共享内存的条件下,使用多处理器。其理由在于线程本身就蕴涵有共享地址的概念。一个多线程的实时程序,利用其中的主线程控制其它的辅助线程,每个处理器用于完成一个辅助的实时计算线程,主线程负责实时时钟的监控,当时钟到达时,启动相应的辅助线程,辅助线程利用图形用户界面(GUI)来监控仿真的进行。

THE USE OF MULTIPLE THREADS IN AN OBJECT-ORIENTED REAL-TIME SIMULATION

As real-time simulations become more complex, a single processor is no longer sufficient to perform all of the necessary computations. It becomes desirable to execute independent sections of a real-time simulation on different processors. The traditional approach to utilizing multiple processors on a symmetric multiprocessor machine involves writing a program composed of one process per processor that interact through shared memory. A program that uses threads can utilize multiple processor without the overhead of full processes or the use of a cumber some shared memory mechanism. This is due to the fact threads implicitly share a common address space. A multithreaded real-time program is organized as a main thread controlling zero or more auxiliary real-time threads. Each processor to be used for real-time computations is assigned a single auxiliary real-time thread. The main thread monitors the real-time clock and informs the auxiliary threads when the clock ticks. An auxiliary thread can also be used to monitor and control the simulation via a graphical user interface ( GUI).