> Its also a rather insidious bug, because the code will run seemingly normally, just... it never actually locks anything. Actually, I think it's worse than th

> Its also a rather insidious bug, because the code will run seemingly normally, just... it never actually locks anything. Actually, I think it's worse than that; IIUC, it will block until the mutex is unlocked, then run. Under light load, it will get away with this, but if the load is heavy enough, it will either guarantee that every process waiting for the lock runs at once, trampling each other's work, or almost-serialize them, making the race condition even more intermittent than if they didn't lock at all. Which failure mode you hit depends on how your scheduler works.