My personal opinion on this is that the thread_interrupted exception should be considered a normal exception. My guideline to use exception vs. assertions is: * if an invariant is broken, use assert * if inputs are out of range, use exceptions, or better exit codes * if the postcondition cannot be guaranteed due to a failure in the interaction with external world, use exceptions I think thread cancellation is an (asynchronous) interaction with external world, so it should be handled exactly in the same way as a timeout connecting to a TCP address, or an error when reading from disk. Moreover, I suggest that, instead of speaking of cancellation, in which the outcome is decided from outside, we should speak of interruption (like in Java, where thread handling was designed together with the language). Interruption is signalling a thread (that may be blocked into a long operation) to become responsive again to some predefined events (one of those, but not the only one, is termination). Corrado -- __________________________________________________________________________ dott. Corrado Zoccolo mailto:zoccolo@di.unipi.it PhD - Department of Computer Science - University of Pisa, Italy -------------------------------------------------------------------------- The self-confidence of a warrior is not the self-confidence of the average man. The average man seeks certainty in the eyes of the onlooker and calls that self-confidence. The warrior seeks impeccability in his own eyes and calls that humbleness. Tales of Power - C. Castaneda