Development of compiler for real-time LOTOS programs with real-time multi-redezvous

在本研究中，我们定义了E-LOTOS的一个子类（称为实时LOTOS），并针对其规范开发了一个编译器。编译器首先将给定的规范分解为多个基本模块，以便每个模块只包含具有发散和迭代的事件序列，然后将每个模块映射到实时线程库中的一个实时线程。在这里，线程之间的交互是用共享变量实现的。为了使每个线程尽最大努力及时执行其定时事件，所有正在运行的线程都设置了它们的唤醒时间和截止日期，以便由EDF（最早截止日期优先）策略调度它们。我们还设计并实现了一种机制来有效地调度线程之间的定时多交会。为了将我们的编译器应用于多媒体系统开发，我们实现了音频/视频处理的原语，并修改了编译器以支持实时LOTOS规范。通过我们开发几个视频播放应用程序的实验，我们已经证实，从面向约束风格的实时LOTOS规范（这使得描述简单，但在实现中引入了同步开销），编译器可以生成实际使用的高效目标代码。

In this research, we define a subclass of E-LOTOS (called realtime LOTOS ) and develop a compiler for its specifications.The compiler first decomposes a given specification into multiple basic modules so that each module includes only event sequences with divergencesand iterations, then it maps each module to a realtime thread on our realtime thread library.Here, interactions between the threads are implemented with shared variables.To make the best effort for each thread to execute its timed events in time, all the running threads set their wake-up time and deadlines so that they are scheduled by EDF( Earliest Deadline First ) policy.We have also designed and implemented a mechanism to efficiently schedule timed multi-rendezvous between threads.To apply our compiler to multimedia system development, we have implemented primitives for audio/video processing and modified our compiler to support them in realtime LOTOS specifications.Through our experiment to develop several video playback applications, we have confirmed that from realtime LOTOS specifications in constraint oriented style (which makes the descriptions simple but introduces synchronization overhead in implementation), the compiler can generate as efficient object codes as to be used practically.