Efficient semaphore management using read/modify/write memory cycles
Richard M. Weatherly, James F. Leathrum · ACM SIGOPS Operating Systems Review · 1982
Denning and Dennis [1] give a method of minimizing semaphore contention utilizing tagged memory, semaphore words, and indivisible microcode segments. A similar method, inspired by their work, has been developed which further reduces the amount of time spent in the critical mutually exclusive section of the semaphore management software. Additionally, through the use of a special read/modify/write memory arrangement, may semaphore operations can be performed in one instruction cycle with the remainder being executed with a minimum of memory contention.