Process synchronization without long-term interlock

Abstract

A technique is presented for replacing long-term interlocking of shared data by the possible repetition of unprivileged code in case a version number (associated with the shared data) has been changed by another process. Four principles of operating system architecture (which have desirable effects on the intrinsic reliability of a system) are presented; implementation of a system adhering to these principles requires that long-term lockout be avoided.