12.6 Operating Systems Aspects

12.6.1 General

The need to use robust, reliable OSs in critical situations will be self-evident to users of personal desktops. Problems encountered in the PC world are many and varied. At the lower end of the frustration, the range is the shutdown of an application accompanied by the message "This program has performed an illegal operation" (baffling when you haven't done anything). Applications may be launched automatically at the most unexpected times, causing havoc with existing work. And, in extreme cases, machines completely lock up, needing to be switched off before operations can resume (a challenging task with a laptop). Well, enraging as this may be, the actual consequences are not especially harmful. However, it should be clear that such behavior is quite unacceptable for mission-critical systems (but not to everybody it seems; one well-known commercial OS was used within the machinery/propulsion systems of the US warship USS...