A computer-implemented method is provided for enabling exactly-once messaging. The computer-implemented method includes transmitting a plurality of messages from a first location to a second location via read requests and write requests made to a memory and controlling the read and write requests by a memory controller including a read queue, a write queue, and a lock address list, each slot of the lock address list associated with a lock bit. The computer-implemented method further includes initiating the read requests from the memory via the memory controller when associated lock bits are enabled and initiating the write requests from the memory via the memory controller when associated lock bits are disabled. The computer-implemented method further includes enabling and disabling the lock bits after the initiation of the write and read requests, respectively.