bugfix-rc-global-stats-race, RED stage (audit trail; GREEN follows
separately via implement mini-mode).
`g_rc_alloc_count`/`g_rc_free_count` (runtime/rc.c:90-91) are plain
`static uint64_t`; the `__ail_tls_ctx == NULL` fallback at rc.c:161
and rc.c:212 does a non-atomic `++`. Concurrent host-side
ailang_rc_alloc/ailang_rc_dec outside a bound ctx race the
read-modify-write and silently drop updates. New C host (8 threads
x 2_000_000 alloc-then-dec, no ailang_ctx_new so the global path is
taken, no box crosses a thread) + integration test asserting the
atexit Σ is exact. Boss-verified RED: allocs=2141382 expected
16000000, live=-131242 (deterministic-fail under this contention,
not flaky).
NOT a memory bug — Ctx:!Send keeps every box on one thread, the
per-object refcount header op is correct, programs are bit-exact;
the only defect is the under-counted statistics Σ (the M5 iter 2
symbol-fan leak-proof finding, b724cd1). Existing green per-ctx
harnesses (embed_swarm_tsan.rs, embed_rc_accounting_tsan.rs) always
bind __ail_tls_ctx, exercising the zero-contention per-thread
counters and never this global fallback — which is why the suite is
green while the bug ships.
Brummel
427b687b95