Weak Updates and Separation Logic
Authors
Gang Tan
Zhong Shao
Xinyu Feng
Hongxu Cai
Abstract
Separation logic provides a simple but powerful technique
for reasoning about low-level imperative programs that use shared data
structures. Unfortunately, separation logic supports only "strong updates",
in which mutation to a heap location is safe only if a unique
reference is owned. This limits the applicability of separation logic when
reasoning about the interaction between many high-level languages (e.g.,
ML, Java, C#) and low-level ones since the high-level languages do not
support strong updates. Instead, they adopt the discipline of "weak updates",
in which there is a global "heap type" to enforce the invariant
of type-preserving heap updates. We present SL^w, a logic that extends
separation logic with reference types and elegantly reasons about the interaction
between strong and weak updates. We describe a semantic
framework for reference types, which is used to prove the soundness of
SL^w. Finally, we show how to extend SL^w with concurrency.
Published
Copyright © 2011 Xinyu Feng
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