Proving Monitors Interesting scheduling and sequential properties of monitors can be proved by using state variables which record the monitor's history and by defining extended proof rules for their wait and signal operations. These two techniques are defined, discussed, and applied to examples to prove properties such as freedom from indefinitely repeated overtaking or unnecessary waiting upper bounds on queue lengths, and historical behavior. CACM May, 1976 Howard, J. monitors, correctness, proof rules, historical variables, concurrency, scheduling, bounded buffer, semaphores, alarm clock, disk head 4.32 4.35 5.24 CA760505 JB January 4, 1978 3:28 PM 2704 4 2866 2738 4 2866 2865 4 2866 2866 4 2866 2866 4 2866 2866 4 2866 2869 4 2866 2898 4 2866 2941 4 2866 2958 4 2866 2972 4 2866 3004 4 2866 3030 4 2866 3043 4 2866 3128 4 2866 3144 4 2866 2356 5 2866 2597 5 2866 2796 5 2866 2866 5 2866 2866 5 2866 2866 5 2866 2938 5 2866 2946 5 2866 3128 5 2866 2150 6 2866 2150 6 2866 2376 6 2866 2436 6 2866 2597 6 2866 2865 6 2866 2866 6 2866 2866 6 2866 2866 6 2866 2870 6 2866 2912 6 2866 3082 6 2866