SOFTWARE DIAGNOSIS USING COMPRESSED SIGNATURE SEQUENCES

Software monitoring and debugging can be efficiently supported by one of the concurrent error detection methods, the application of watchdog processors. A watchdog processor, as a co-processor, receives and evaluates signatures assigned to the states of the program execution. After the checking, it stores the run-time sequence of signatures which identify the statements of the program. In this way, a trace of the statements executed before the error is available. The signature buffer can be efficiently utilized if the signature sequence is compressed. In the paper, two real-time compression methods are presented and compared. The first one uses predefined dictionaries, while the other one utilizes the structural information encoded in the signatures