1. A method for controlling access to resources shared among a plurality of logical processors, comprising: obtaining exclusive access for a first logical processor to a resource descriptor describing a usage allocation of said shared resources; querying said resource descriptor to determine whether resources needed by said first logical processor are available; if resources needed by said first logical processor are available, updating said resource descriptor to reserve said resources for exclusive use by said first logical processor; and releasing said exclusive access for said first logical processor to said resource descriptor.