Dual Valid Bit Set for Multi-Node Cache Contention

The patent applies preliminary action by setting the valid bit to inhibit new requests before contention actually occurs. When a request is rejected, the valid bit is set to prevent other requests from entering the nest during the resolution period, eliminating the need for continual retry cycles and improving timeliness while maintaining simple hardware architecture.

The patent applies self-service by using the existing valid bit mechanism to automatically stall new requests when contention is detected. The system uses its own operational state (valid bit status) to control request admission, eliminating the need for separate hang detection monitoring mechanisms while maintaining timeliness.

The patent applies local quality by ensuring ordering only at the point of contention (the nest) rather than globally throughout the entire system. The valid bit mechanism ensures that requests are processed in order at the critical section where contention occurs, while allowing other parts of the system to operate independently, thus achieving necessary ordering without full serialization complexity.

The patent applies dynamics by making the system state changeable through the valid bit. The valid bit dynamically transitions from inactive to active when contention is detected, automatically adjusting request admission behavior to ensure fairness. This dynamic mechanism maintains productivity by allowing continuous requests under normal conditions while ensuring fairness when contention occurs, without requiring manual intervention or complex algorithms.