Abstract

By compile-time type analysis of a program written in a statically typed first-order polymorphic language, it is possible to generate a mark-sweep or copying garbage collector for that program which does not require runtime tags on the data, which operates in linear time in the size of the data and stack, and, excepting the use of a per-pointer mark bit, within a small, bounded workspace---desirable in an algorithm which is only invoked when space is exhausted. The basis for the new graph marking algorithm, the compile time type analysis required, and safety in the presence of sharing is described for languages employing a first-order subset of the Hindley-Milner typing discipline; it is also immediately applicable to monomorphic, type-safe programming languages, such as PASCAL. The algorithm is the first tag-free marking algorithm for values of arbitrary algebraic type requiring less than linear space in the worst case. Keywords: polymorphic, tagless, tag-free, garbage collection, gr...

Citations