A formal soundness proof of region-based memory management for object-oriented paradigm.

Region-based memory management has been proposed as a viable alternative to garbage collection for real-time applications and embedded software. In our previous work we have developed a region type inference algorithm that provides an automatic compile-time region-based memory management for object-oriented paradigm. In this work we present a formal soundness proof of the region type system that is the target of our region inference. More precisely, we prove that the object-oriented programs accepted by our region type system achieve region-based memory management in a safe way. That means, the regions follow a stack-of-regions discipline and regions deallocation never create dangling references in the store and on the program stack. Our contribution is to provide a simple syntactic proof that is based on induction and follows the standard steps of a type safety proof. In contrast the previous safety proofs provided for other region type systems employ quite elaborate techniques

Advanced flow-based type systems for object-oriented languages

Ph.DDOCTOR OF PHILOSOPH

Garbage Collection Safety for Region-based Memory Management

In this paper, we prove the safety of integrating region-based memory management and Cheney-style copying garbage collection. The safety property relies on a refinement of the region typing rules that forbids dangling pointers during evaluation. To accommodate the triggering of garbage collection at any step in the evaluation process, we base our type-safety result for the region-based system on a small-step contextual semantics and show that whenever a well-typed expression reduces to another expression, possibly by deallocating a region, then no dangling pointer is introduced. Because there are no dangling pointers in the initial heap, no dangling pointers appear during evaluation

ABSTRACT Garbage Collection Safety for Region-based Memory Management

In this paper, we prove the safety of integrating region-based memory management and Cheney-style copying garbage collection. The safety property relies on a refinement of the region typing rules that forbids dangling pointers during evaluation. To accommodate the triggering of garbage collection at any step in the evaluation process, we base our type-safety result for the region-based system on a small-step contextual semantics and show that whenever a well-typed expression reduces to another expression, possibly by deallocating a region, then no dangling pointer is introduced. Because there are no dangling pointers in the initial heap, no dangling pointers appear during evaluation. Although in principle, the refinement of the region typing rules leads to less flexibility and can cause worse memory behavior than when dangling pointers are permitted, experiments show that, for a range of benchmark programs, the refinement has little effect on overall memory behavior