New dimensions in heap profiling

Abstract

First-generation heap profilers for lazy functional languages have proved to be effective tools for locating some kinds of space faults, but in other cases they cannot provide sufficient information to solve the problem. This paper describes the design, implementation and use of a new profiler that goes beyond the two-dimensional ‘who produces what’ view of heap cells to provide information about their more dynamic and structural attributes. Specifically, the new profiler can distinguish between cells according to their eventual lifetime, or on the basis of the closure retainers by virtue of which they remain part of the live heap. A bootstrapping Haskell compiler (nhc) hosts the implementation: among examples of the profiler's use we include self-application to nhc. Another example is the original heap-profiling case study clausify, which now consumes even less memory and is much faster.

Heap profiling for space efficiency

“…Extended with whole-module producers and whole-type constructors, the pro ler could be used to improve the spacee ciency of large programs, such as compilers 7]. Limitations of a`who produces what' view of the heap prompted the subsequent development of the nhc pro ler, with its extensions to dynamic characteristics of heap cells: see 5] for details of retainer pro ling 4 ; see 9] for more about biographical pro ling.…”

How to look busy while being as lazy as ever: the Implementation of a lazy functional debugger

“…Note that we are not concerned with performance debugging (or profiling) here. That area has been successfully addressed by others(Runciman & Wakeling, 1993;Runciman & Röjemo, 1996;Sansom & Peyton Jones, 1995).…”