A conflict resolution technique provides consistency such that all conflicts
can
be detected by at least one of the conflicting requestors if each node monitors
all requests after that node has made its own request. If a line is in the Exclusive,
Modified or Forward state, conflicts are resolved at the node holding the unique
copy. The winner of the conflict resolution, and possibly the losers, report the
conflict to the home node, which pairs conflict reports and issues forwarding instructions
to assure that all requesting nodes eventually receive the requested data. If a
requested cache line is either uncached or present only in the Shared state, the
home node provides a copy of the cache node and resolves conflicts. In one embodiment,
a blackout period after all responses until an acknowledgement message has been
received allows all conflicting nodes to be aware of conflicts in which they are involved.