CppMem
lastmod 2026-11-10created 2017-07-162 edits
CppMem is an interactive web tool that enumerates and shows every possible execution outcome of a small program under the C/C++11 memory model. When you enter code that uses std::atomic operations and memory orders, it draws the standard's relations such as happens-before and synchronizes-with as a graph, letting you check for data races and the permitted execution orders. It was built at the University of Cambridge as part of research on formalizing memory models, and is used as a learning tool for verifying the subtle behavior of lock-free code.
CppMem: an interactive C/C++ memory model explorer