Summary: ­­ ­­
Computer Sciences Technical Report #1051, September 1991, Revised September 1992
A Unified Formalization of Four Shared­Memory Models
Sarita V. Adve
Mark D. Hill
Department of Computer Sciences
University of Wisconsin
Madison, Wisconsin 53706
ABSTRACT
This paper presents a shared­memory model, data­race­free­1, that unifies four earlier models: weak order­
ing, release consistency (with sequentially consistent special operations), the VAX memory model, and data­
race­free­0. The most intuitive and commonly assumed shared­memory model, sequential consistency, limits per­
formance. The models of weak ordering, release consistency, the VAX, and data­race­free­0 are based on the
common intuition that if programs synchronize explicitly and correctly, then sequential consistency can be
guaranteed with high performance. However, each model formalizes this intuition differently and has different
advantages and disadvantages with respect to the other models.
Data­race­free­1 unifies the models of weak ordering, release consistency, the VAX, and data­race­free­0
by formalizing the above intuition in a manner that retains the advantages of each of the four models. A multipro­
cessor is data­race­free­1 if it guarantees sequential consistency to data­race­free programs. Data­race­free­1
unifies the four models by providing a programmer's interface similar to the four models, and by allowing all

Source: Adve, Sarita - Department of Computer Science, University of Illinois at Urbana-Champaign

Collections: Computer Technologies and Information Sciences