Shared Memory Atomic Operations Across Coherence Domains

The patent introduces a switch device as an intermediary between multiple hosts to coordinate atomic memory accesses. The switch device implements a directory structure that tracks ownership of memory locations and coordinates access requests, replacing the need for hosts to use complex networking semantics directly. This intermediary approach reduces latency by handling coordination centrally while maintaining system compatibility.

The patent segments the memory system into multiple coherence domains, each associated with a specific host or virtual hierarchy. The directory structure is segmented to track ownership within each domain independently. This segmentation allows atomic operations to be coordinated locally within domains rather than requiring global networking semantics, reducing latency while maintaining ease of operation through modular design.

The switch device acts as an intermediary that enables memory sharing across independent hosts while maintaining high bandwidth. It implements a directory structure that efficiently tracks and manages shared memory access rights, allowing multiple hosts to access the same memory locations with high-speed interconnects rather than through slower networking semantics. This achieves both high productivity and adaptability.

The patent introduces a new dimension of memory sharing by implementing cross-host coherence domains. Instead of limiting memory sharing within single-host boundaries, the directory structure enables memory locations to be shared across multiple hosts simultaneously, creating a multi-dimensional memory access topology that increases both bandwidth and versatility.

The switch device serves as a reliable intermediary that ensures atomic access correctness across multiple virtual hierarchies. The directory structure maintains ownership information and coordinates access requests to guarantee atomicity, while the high-speed interconnect eliminates the latency associated with traditional networking-based coordination methods.

The patent implements preliminary action by having the directory structure pre-establish ownership records for memory locations before atomic operations occur. When a host wants to perform an atomic operation, the ownership information is already available in the directory, allowing immediate coordination without the latency of establishing coherence protocols in real-time. This preliminary setup maintains reliability while reducing coordination latency.