Abstract: A technique to share cache lines among a plurality of bus agents. Embodiments of the invention comprise at least one technique to allow a number of agents, such as a processor or software program being executed by a processor, within a computer system or computer network to transfer ownership of a locked (“owned”) cache line, under certain circumstances, without incurring as much of the operational overhead and resulting performance degradation of many prior art techniques.

Abstract: Systems and method are disclosed for providing responses for different cache coherency protocols. One embodiment may comprise a system that includes a first node employing a first cache coherency protocol. A detector associated with the first node detects a condition based on responses provided by the first node to requests provided according to a second cache coherency protocol, the second cache coherency protocol being different from the first cache coherency protocol. The first node provides a response to a given one of the requests to the first node that varies based on the condition detected by the detector.

Abstract: A system comprises a first node having an associated cache including data having an associated first cache state. The first cache state is capable of identifying the first node as being an ordering point for serializing requests from other nodes for the data.