Verification of error recovery specification for distributed data by using colored Petri net

In systems where the same data are distributed in plural memories, it is important for designers to verify that error recovery procedures maintain data consistency after a failure. A modeling and validation method of error recovery specifications by using colored Petri nets is proposed. The analysis of reachable states is useful to consistency. The introduction of the equivalence relation into reachable states reduces the number of the states to be verified. The proposed approach was applied to read/write control of a disk controller with a built-in cache memory