FSM modelling the protocol behaviour of an
implementation of the OS1 RPC client protocol
machine. There are 16 states in the diagram,
representing 16 stages the client may go through
during a remote procedure call, and 18 transitions
between those states. Associated with a transition
are labels representing the action the client will
perform to complete the transition and the
probability that the transition will take place,
respectively. There are two kinds of actions:
processing actions (marked with "-") and waiting
actions (marked with "+"). The processing actions
require services from the processor that executes
the implementation of the client RPC protocol
machine. The waiting actions are simply delays that
the client RPC protocol machine has to experience
and therefore do not consume the processor
resource. Both processing actions and waiting
actions consume time that varies from action to
action. While most of these probabilities are fixed
to one by the OS1 RPC protocol specification, some
of them are dependent on the implementation and
applications. The probabilities that are equal to one
are not shown in the figure. We use p i j , i,
j = 1 ,..., 16, to represent the probability that a
transition will take place from state i to statej.