marcel@ADS.COM (Marcel Schoppers) (05/30/90)
The pointer to the "Embedded Systems Programming" Mag I cited has already been posted. It's a fairly light-weight mag (I think), and the article I cited was one of the few I found instructive. Most of the mag's articles are practical things like, how to implement lookup tables, how to get good performance for FFTs, how to implement a memory management system for realtime applications, etc. As for the project I'm working on, the communication options I posted recently were reviewed as part of a language for mobile robot programming. I found that Occam and Ada (and many RT executives) support only synchronous communi- cation, which was not at all what I wanted; so I used the Ripps article as a springboard for deciding what I did want (channels with dynamically variable sets of sources & sinks, which can of course be implemented using synchronous communication but at considerable expense of patience). The project has also turned up the desirability of being able to nest concurrent tasks into "group tasks" such that a single SUSPEND, RESUME or priority change on a "group task" will affect every task included in the group. That's a first approximation; the accurate version is that tasks can belong to one or more "group tasks", and are enabled for execution only if they belong to at least one "group task" that is enabled (i.e. a SUSPEND on a "group task" will suspend a task in that group only if that task doesn't belong to another enabled group). I don't suppose that such a capability already exists in some well-supported language or system? The above two ideas are the only ones in my project (so far) that are relevant to this group. Sorry. Marcel