mm_hp

• A performant, complete implementation of C++26 hazard pointers ([saferecl.hp]) for Linux x86_64.
• Intended as guidance for standard library implementers on ABI robustness and as a performance reference point.
• For readability, internal names deliberately avoid using the standard library __x reserved style.
• Licensed so that standard library implementers can take all or part of this code — see LICENSES.
• If an implementation needs different terms, additional licenses may be considered.
• Bug reports and written suggestions are welcome; patches and code cannot be accepted in order to keep the copyright in one place to facilitate adding licenses.
• No guarantee of support of any kind.

Performance results

Operation                                    1-thread ns/op   8-thread scalability
load and dereference, unprotected            0.233            7.97x
+ hazard pointer protection                  0.410 (Δ 0.177)  7.83x
+ hazard pointer ctor/dtor per iteration     1.725 (Δ 1.492)  7.91x

• 10,000 pre-existing hazard pointers make no measurable difference.
• Measured with hp_bench.
• Extracted from mm_hp-2026-09-07-142544.txt.