Distributed-directory scheme: Stanford distributed-directory protocol

The Stanford distributed-directory (SDD) cache-coherence protocol, based on a singly linked list of distributed directories, is examined. Sharing-list additions and removals are explained diagramatically. Reads, writes, pending signals, replacement, and synchronization are discussed. Replacing lines linked in a list is done by invalidating the lower part of the list. A doubly linked list may be used to patch the list in case of replacements. However, in practice, performance improvement depends on the list lengths and access patterns. A distributed-directory cache-coherence protocol allows efficient implementation of locks at minimal extra cost. The SDD protocol allows a lock implementation that minimizes network traffic.<>