WeirdPerformance 2.4-B — GC Safe Sweep test

Strict A/B experiment for WoW 1.12.1 build 5875.

Baseline

Keep the validated 2.4-A binary unchanged:

weirdperformance.dll
SHA-256: d35168ae06c19087ef9b7c68918a054640396dfbfcef0664e18e9372284b5eef

B variant

Add:

weirdperformance_gc24b.dll

The companion changes only Lua GC behavior. It does not replace or rebuild the validated 2.4-A DLL.

The implementation is based on the historical pre-generational incremental sweep: WoW keeps its native mark, userdata/string sweep, memory shrink and finalizers. Only the main rootgc sweep is split into 50,000-object chunks.

Safety changes versus the old experiment

hooks only luaC_collectgarbage and lua_close;
no overlap with the lifecycle hooks referenced by the validated 2.4-A binary;
any fragmented sweep is reconnected before native lua_close destroys the Lua state;
GC calls made from inside lua_close stay native;
the birth-mark byte is ownership checked and restored only while still owned;
a changed Lua global_State forces native fallback rather than reconnecting stale pointers;
hook installation is transactional;
no generational age bitmap, no write barriers, no GC tuning, no profiling/RDTSC.

Installation for the test

Keep both DLLs next to WoW and list both in dlls.txt:

weirdperformance.dll
weirdperformance_gc24b.dll

Removing weirdperformance_gc24b.dll returns you exactly to the validated 2.4-A baseline.