- class ironic.common.fsm.FSM¶
An ironic state-machine class with some ironic specific additions.
- add_state(state, on_enter=None, on_exit=None, target=None, terminal=None, stable=False)¶
Adds a given state to the state machine.
stable – Use this to specify that this state is a stable/passive state. A state must have been previously defined as ‘stable’ before it can be used as a ‘target’
target – The target state for ‘state’ to go to. Before a state can be used as a target it must have been previously added and specified as ‘stable’
Further arguments are interpreted as for parent method
- add_transition(start, end, event, replace=False)¶
Adds an allowed transition from start -> end for the given event.
start – starting state
end – ending state
event – event that causes start state to transition to end state
replace – replace existing event instead of raising a
Duplicateexception when the transition already exists.
- initialize(start_state=None, target_state=None)¶
Initialize the FSM.
start_state – the FSM is initialized to start from this state
target_state – if specified, the FSM is initialized to this target state. Otherwise use the default target state
Is the state stable?
state – the state of interest
InvalidState if the state is invalid
True if it is a stable state; False otherwise
- process_event(event, target_state=None)¶
process the event.
event – the event to be processed
target_state – if specified, the ‘final’ target state for the event. Otherwise, use the default target state
- property target_state¶