Processing data communications messages with an Input/Output Control Block (‘IOCB’) ring that includes a number of IOCBs characterized by a priority and arranged in sequential priority for serial operation, where processing the messages includes depositing message data in one or more IOCBs according to depositing criteria; processing, by a message processing module associated with an IOCB having a priority less than the present value of a state counter, the message data in the IOCB while a message processing module associated with an IOCB having a next priority waits; increasing, upon completion of processing the message data of the IOCB having a priority less than the present value of the state counter, the present value of the state counter to a value greater than the next priority; and processing, by the message processing module associated with the IOCB having the next priority, the message data in the IOCB.