HISAOR

Software errors can arise suddenly due to unforeseen circumstances. The phrase ‘a failure mode we did not think of' is not unknown among software developers. The resulting error typically occurs without warning. Hardware errors can also occur without warning due to radiation or other factors. Some protection against hardware CPU failures can be obtained by exploiting redundancy and running the same task on multiple CPUs, and OCEOSmp supports this. Protection against memory errors is usually provided by EDAC. It is expected that an appropriate trap handler is put in place by the application to handle uncorrectable errors signalled by an EDAC system. The timed actions feature of OCEOSmp simplifies restarting a memory scrubber task at set time intervals, and allows the time interval be changed at run time depending on the error rate. Memory protection may also be provided by memory protection units which restrict defined memory address ranges to use only for execution code or for reading..