Bridge and method for coupling a requesting interconnect and a serving interconnect in a computer system

A bridge for coupling a requesting interconnect and a serving interconnect connected to a number of coherent units in a computer system is disclosed. The bridge includes N machines 131-13N, a tracking entity 121, a first arbiter 122, and a second arbiter 123. Each of the N machines is configured to handle requests from the requesting interconnect and to handle allocated responses from the serving interconnect. Each of the N machines has an allocated local count. The tracking entity is configured to track priorities of the N machines for issuing received requests to the serving interconnect and for issuing received responses to the requesting interconnect based on the N local counts. The first arbiter is configured to arbitrate the received requests to be issued to the serving interconnect based on the tracked priorities. Further, the second arbiter is configured to arbitrate the received responses to he issued to the requesting interconnect based on the tracked priorities. The tracking entity is configured to track the priorities of the N machines for handling requests based on the N local counts and a status of each of the N machines. The invention is said to improve the ordering for requests while supporting retries.