A modified transaction registration protocol is disclosed. The registration protocol
is inherently centralized in that processes requesting registration to participate
in the work of a transaction, must send a request to a Broadcast Owner CPU which
is the CPU that initiated the transaction. The processes wait, suspended, until
a response is received from the Broadcast Owner CPU. However, if the Broadcast
Owner CPU fails to respond to the registration request, then the processes that
are waiting are incapable performing work for the transaction. While a CPU failure
may not occur often, in a fault-tolerant system, such events must be accounted
for. Therefore, the transaction registration protocol is modified to revert to
a Full Broadcast transaction protocol and complete any outstanding registration
requests. This is accomplished by distributing transactions to all of the CPUs
in the system, and in each CPU forcing the completion of registration requests
in each CPU.