Concurrent Process Monitoring with No Reference Signatures

A simple, inexpensive and time/space efficient signature technique for process monitoring is presented. In this technique, a known signature function is applied to the instruction stream at compilation phase and when the accumulated signature forms an m-out-of-n code, the corresponding instructions are tagged. Error checking is done at runtime by monitoring the signatures accumulated at the tagged locations to determine whether they form m-out-of-n codes. This approach of signature checking does not require the embedding of reference signatures at compilation, thereby leading to savings in memory as well as in execution time. The m-out-of-n code approach offers high error coverage and controllable latency. The results of the experiments conducted to verify the controllability of the latency are discussed. One of the distinguishing features of the proposed scheme is the elimination of reference signatures, which are the main source of memory and time overhead in the existing techniques.