Actor: User Application

Goal: Cancel a service invocation.

Description: Cancel a service invocation.

Preconditions:

1. The engine must be started.
2. The service invocation is not complete.
3. The service call to cancel must be valid.

None.

Priority: High

Related Use Cases:

UC22.0 - Invoke Network Service
UC23.0 - Invoke Network Service (Async)

Notes and Issues:

None

Event Flow:

1. The application asks the engine to cancel an invocation sent to a peer.
2. The engine informs the peer to cancel the invocation.
3. The remote engine removes the invocation from its in-progress list.
4. The local engine removes the invocation from its in-progress list.

UC24.1 Engine is not started

1. The application asks the engine to cancel an invocation sent to a peer.
2. The engine returns an error that the it has not been started.

UC24.2 Service call doesn't exist

1. The application asks the engine to cancel an invocation sent to a peer.
2. The engine returns an error that the service call doesn't exist.

UC24.3 Service call already complete

1. The application asks the engine to cancel an invocation sent to a peer.
2. The engine returns an error that the engine has already invoked the message.

Sequence Diagrams:

Revision History

Name	Date	Reason for Change	Version