PETCHER%SVDSD@eg.ti.COM (06/17/87)
Let's not curse UNIX for its view of computation. Let's understand UNIX for the computational environment for which it was designed. Like all general purpose, multi-user operating systems, its main priority is the efficient sharing of computer resources among multiple users. I will not comment on how well it does this, but suffice it to say it was not designed as a real-time operating system, and should not be expected to perform well as one. In fact, even systems such as RSX11-M, which DOES purport to be designed to support real-time applications, exacts a frequently unacceptable overhead on such programs. In my 10+ years of experience with real-time multitasking, the only viable approach has always been the same: Bypass the operating system. Sad but true, that has been the only way to meet system performance goals in the face of the need for concurrent tasking and I/O. I have pitched, on more than one occasion, the need for an effective real-time embedded OS that need not compromise performance in order to support multiple interactive users. In a sense, the bare machine Ada systems are meeting this need, perhaps in the only way possible, at high cost, but at least in a way that absolves the application programmer of having to design and maintain an operating system, as was done in the past. So the answer is, use UNIX if UNIX is what you need, but don't use it then curse it if it's the wrong thing to use in the first place. The opinions expressed are my own Malcolm Petcher Texas Instruments, Inc.