Synchronization with eventcounts and sequencers (Extended Abstract)

Abstract

The design of computer systems to be concurrently used by multiple, independent users requires a mechanism that allows programs to synchronize their use of shared resources. Many such mechanisms have been developed and used in practical applications. Most of the currently favored mechanisms, such as semaphores and monitors are based on the concept of mutual exclusion . In this paper, we describe an alternative synchronization mechanism that is not based on the concept of mutual exclusion, but rather on observing the sequencing of significant events in the course of an asynchronous computation. Two kinds of objects are described, an eventcount, which is a communication path for signalling and observing the progress of concurrent computations, and a sequencer, which assigns an order to events occurring in the system.