English

Heap vs. Stack: Analyzing Memory Allocations in C and C++ Open Source Software

Programming Languages 2024-10-10 v2

Abstract

In C++, objects can be allocated in static memory, on the stack, or on the heap -- the latter being significantly more performance-costly than the former options. We hypothesized that programmers, particularly those involved in widely-used open-source projects, would be conscious of these performance costs and consequently avoid heap allocations. To test this hypothesis, we compiled and executed 797 automated tests across 13 C and 10 C++ open GitHub projects, measuring their heap allocations with Valgrind and stack allocations using DynamoRIO instrumentation. Our findings showed a wide variation in heap allocations, ranging from 0 to 99\% with an average of 9.26\%. We also found that C++ programs use heap less frequently than C programs. Contrary to our initial intuition, this suggests that heap allocations are actively employed in both C and C++ programs. Determining the prevalence of objects in these allocations remains a topic for future research.

Keywords

Cite

@article{arxiv.2403.06695,
  title  = {Heap vs. Stack: Analyzing Memory Allocations in C and C++ Open Source Software},
  author = {Roman Korostinskiy and Eugene Darashkevich and Roman Rusyaev and Yegor Bugayenko},
  journal= {arXiv preprint arXiv:2403.06695},
  year   = {2024}
}
R2 v1 2026-06-28T15:15:43.764Z