phil henshaw wrote: > Are there self-protecting sentinel circuits or routines to catch them > in the act and shut them down? A couple examples come to mind:
1) floating point hardware knows when calculations have gone bad due to underflow, overflow, divide by zero, etc. The operating system kernel can notice these and signal them as exceptions, if the user prefers. The sanity checks are in hardware as are the task switching / recovery mechanisms for inspecting them. 2) The memory management unit of computer knows about the mapping from physical addresses to virtual ones and knows the difference between valid and invalid memory addresses. Addresses can be handed out and reclaimed such that bad addresses due to programming mistakes cause hardware traps (e.g. the Electric fence malloc library). A crude form of this is for Unix users is the segfault or a bus error signals. ============================================================ FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
