[mikets]

I agree with Greg. A task either died unexpectedly or got killed is not a planned event. Therefore, the state of the whole program could be in jeopardy. If the task had allocated global resources, they were not released. If you restart the task, you may end up with duplicate resouces. The result could be totally unpredictable. In fact our code avoids spinning new threads unless the task is timing critical (need accurate timed execution). Even with most of the time critical scenarios, we found ways to do things coorpoeratively instead of needing to create new threads. I assume the threads in vxWorks are scheduled preemptively. Preemptive multi-tasking can interrupt you at any point in your code. That's why you need semaphores to protect a certain code region from being re-entered. Dealing with semaphore improperly will cause deadlock. That's not easy to debug especially if the deadlock is caused by some race conditions that don't reproduce predictably.

BTW, does anybody know the interval of a time slice in vxWorks? I found that if I created a Notifier with a given period, say 5 ms, my Notifier got called in 20+ ms instead. I suspect it has something to do with the timer tick interval in vxWorks. Am I correct? If so, what is that interval, 20 ms?

Thanks.