A method for managing common means of a plurality of processing units

摘要

The invention provides for resource allocation logic for a computer system including a plurality of processors (17, 21) which share access to, and control of, a plurality of resources, such as disk drive units (31-35, 41-45) or busses (51-55). Resource allocation logic (300) coordinates the execution of requests received from the processors to avoid resource sharing inefficiencies and deadlock situations. The allocation logic (300) maintains a "request" queue for each processor (17, 21), seeking to satisfy all requests quickly and fairly. The queues contain an entry corresponding to each request received from its corresponding processor and an identification of resources that are required by the entry's corresponding request. The allocation logic (300) also maintains a "resources available" status array of resources which are not currently in use by any processors, or are not reserved for future use by any processors. The logic repeatedly compares each entry in the request queues with the entries in the resources available status array to detect an entry in the request queue identifying resources all of which are contained in the resources available status array. Once the allocation logic (300) can satisfy a particular request, it signals a grant to the requesting processor for the resources requested and the requested resources are removed from the resources available status array. Upon conclusion of execution of the granted request, the resources are again released to the resource allocation logic (300) for utilization by other resource requests.