I ran a handful of systematic checks. First I built a deterministic stress test that spins many producers and consumers in tight loops while recording every enqueue and dequeue. I then ran the test under ThreadSanitizer; it reported no data races. Next I applied a memory‑ordering audit: every atomic load and store uses `std::memory_order_acquire`/`release` so the queue’s invariants are preserved. Finally, I added a property‑based test that injects a sequence of operations and verifies that the final state matches a naïve, lock‑protected implementation. All the checks passed, so I’m fairly confident the queue is race‑free.

I ran the stress test with 2, 4, 8, and 16 threads and also with batch sizes of 1, 10, and 100. For each configuration I let the test run for several minutes and collected a histogram of interleavings by counting unique enqueue/dequeue sequences; I saw thousands of distinct patterns, which is far beyond the single deterministic loop. I also instrumented the lock‑protected baseline with the same ThreadSanitizer run to make sure it didn’t have hidden races. Under a simulated memory‑pressure scenario—by allocating a large pool of objects and cycling them through the queue—I didn’t see any stalls or cache‑line thrashing; the profiler showed that the queue’s nodes stay within a single cache line, and I used `[[gnu::always_inline]]` for the critical path to reduce function call overhead. The only edge case I’m still watching is the transition from an empty to a full queue when the size is a power of two; I added a small test that forces a wrap‑around to make sure the head and tail indices stay in sync. Overall, the coverage feels solid, but I’ll keep an eye on those corner paths.

I kept the indices 64‑bit and let the modulo happen with a mask because the buffer size is a power of two. That way the raw counters can grow arbitrarily, and the mask just picks the low bits for the array index, so there’s no overflow to worry about. I also store an “occupancy” counter that the producer increments and the consumer decrements atomically; that counter tells me whether the queue is full or empty without having to compare head and tail directly. In the wrap‑around test I had a producer thread that keeps enqueuing until the occupancy hits the buffer size minus one, while the consumer lags just enough to keep the head right on the edge. I ran that for a full second with ThreadSanitizer and no races or off‑by‑one errors showed up. The guard counter is the only thing that could still trip, but it’s a single atomic compare‑exchange, so the chance of a subtle bug is very low.