Ada gets groomed for the whole spectrum of real-time duties

Ada is a high level language, designed for implementzng large embedded systems. It became an ANSI standard in 1983 and in 1988 the Ada Joint Program Ofice established the ADA-9X project far the revision of the Ada standard. One of the specific areas addressed by the revision team deals with requirements posed by real-time applications and introduces a new building block for real-time Ada: the protected record. Protected records provide a low level data-oriented synchronization mechanism and are a primary support for real-time systems. They can be used to efficiently program solutions for real-time problems such as mutual exclusion, conditionally shared data, counting semaphores and signals. This paper compares two diflerent approaches for the solution of a classical realtime problem: conditional critical regions. The first solution uses Ada83 taskang and the second one uses Ada9X protected records .Finally we will discuss the runtime support and some implementation issues for protected records on multiprocessor jarget systems.