It's "atomic" in the sense that it does one thing. It lets you do "actions", not "transactions". A transaction would allow you to do multiple things. If the

It's "atomic" in the sense that it does one thing. It lets you do "actions", not "transactions". A transaction would allow you to do multiple things. If the atomics API gave you ability to do multiple things, you wouldn't need compareExchange, because you could just do compare and then exchange.