next up previous contents index
Next: Delegation Connector Up: Interoperability Previous: Conforms-Relation   Contents   Index


Protocols

To decide whether interfaces with respect to protocols are interoperable, one should select protocol languages that are be decidable. For the PCM usually finite state machines or regular expressions, respectively are used. For such regular languages the inclusion problem is solvable.

The definition of protocols of interfaces of components is not mandatory. If a interface of a component does not define a protocol one usually wants to check component interoperability anyway. For those cases in which there is no explicitly defined protocol the PCM assumes a trivial protocol. Figure 3.12 shows an example of a trivial protocol, that is implicitly assumed. The trivial protocol allows service calls in arbitrary orders.

Figure 3.12: Trivial protocol (visualised as finite state machine): service calls can be done in an arbitrary orders
Image cm-trivial-protocol-01

If a component does not define an explicit protocol for one of its interfaces, the interoperability check can be done in the same way like described in section 3.2.6.1 using the trivial protocol.

Provided component types do not make a mandatory definition of their required interfaces. If a interoperability check for such a component type has to be performed, one assumes exactly one interface. This interface is empty. The interface defines no services and a protocol, who's accepted language is empty ( $ L = \emptyset$). The usual interoperability check can be used for provided component types, too.


next up previous contents index
Next: Delegation Connector Up: Interoperability Previous: Conforms-Relation   Contents   Index
Snowball 2007-03-16