public void Start(
AsyncPassiveStateMachine <int, int> machine,
bool entryActionExecuted)
{
"establish an initialized state machine".x(() =>
{
machine = new AsyncPassiveStateMachine <int, int>();
machine.AddExtension(this.testExtension);
machine.In(TestState)
.ExecuteOnEntry(() => entryActionExecuted = true);
machine.Initialize(TestState);
});
"when starting the state machine".x(() =>
machine.Start());
"should set current state of state machine to state to which it is initialized".x(() =>
this.testExtension.CurrentState.Should().Be(TestState));
"should execute entry action of state to which state machine is initialized".x(() =>
entryActionExecuted.Should().BeTrue());
}
public void Reinitialization(
AsyncPassiveStateMachine <int, int> machine,
Exception receivedException)
{
"establish an initialized state machine".x(async() =>
{
machine = new AsyncPassiveStateMachine <int, int>();
await machine.Initialize(TestState);
});
"when state machine is initialized again".x(async() =>
{
try
{
await machine.Initialize(TestState);
}
catch (Exception e)
{
receivedException = e;
}
});
"should throw an invalid operation exception".x(() =>
{
receivedException
.Should().BeAssignableTo <InvalidOperationException>();
receivedException.Message
.Should().Be(ExceptionMessages.StateMachineIsAlreadyInitialized);
});
}
public void BeforeExecutingEntryActions(
AsyncPassiveStateMachine<string, int> machine,
IExtension<string, int> extension)
{
"establish an extension".x(()
=> extension = A.Fake<IExtension<string, int>>());
"establish a state machine using the extension".x(async () =>
{
machine = new AsyncPassiveStateMachine<string, int>(Name);
machine.AddExtension(extension);
machine.In("0")
.On(1).Goto("1");
await machine.Initialize("0");
await machine.Start();
});
"when firing an event onto the state machine".x(()
=> machine.Fire(1));
"it should call EnteringState on registered extensions for target state".x(()
=> A.CallTo(() => extension.EnteringState(
A<IStateMachineInformation<string, int>>.That.Matches(x => x.Name == Name && x.CurrentStateId == "1"),
A<IState<string, int>>.That.Matches(x => x.Id == "1"),
A<ITransitionContext<string, int>>.That.Matches(x => x.EventId.Value == 1)))
.MustHaveHappened());
}
public void EventsQueueing(
IAsyncStateMachine <string, int> machine)
{
const int firstEvent = 0;
const int secondEvent = 1;
bool arrived = false;
"establish a passive state machine with transitions".x(() =>
{
machine = new AsyncPassiveStateMachine <string, int>();
machine.In("A").On(firstEvent).Goto("B");
machine.In("B").On(secondEvent).Goto("C");
machine.In("C").ExecuteOnEntry(() => arrived = true);
machine.Initialize("A");
});
"when firing an event onto the state machine".x(() =>
{
machine.Fire(firstEvent);
machine.Fire(secondEvent);
machine.Start();
});
"it should queue event at the end".x(()
=> arrived.Should().BeTrue("state machine should arrive at destination state"));
}
public void CustomTypesForStatesAndEvents(
AsyncPassiveStateMachine <MyState, MyEvent> machine,
bool arrivedInStateB)
{
"establish a state machine with custom types for states and events"._(async() =>
{
machine = new AsyncPassiveStateMachine <MyState, MyEvent>();
machine.In(new MyState("A"))
.On(new MyEvent(1)).Goto(new MyState("B"));
machine.In(new MyState("B"))
.ExecuteOnEntry(() => arrivedInStateB = true);
await machine.Initialize(new MyState("A"));
await machine.Start();
});
"when using the state machine"._(() =>
machine.Fire(new MyEvent(1)));
"it should use equals to compare states and events"._(() =>
arrivedInStateB.Should().BeTrue("state B should be current state"));
}
public void OtherwiseGuard(
AsyncPassiveStateMachine <int, int> machine,
CurrentStateExtension currentStateExtension)
{
"establish a state machine with otherwise guard and no machting other guard".x(async() =>
{
machine = new AsyncPassiveStateMachine <int, int>();
currentStateExtension = new CurrentStateExtension();
machine.AddExtension(currentStateExtension);
machine.In(SourceState)
.On(Event)
.If(() => Task.FromResult(false)).Goto(ErrorState)
.Otherwise().Goto(DestinationState);
await machine.Initialize(SourceState);
await machine.Start();
});
"when an event is fired".x(()
=> machine.Fire(Event));
"it should_take_transition_guarded_with_otherwise".x(()
=> currentStateExtension.CurrentState.Should().Be(DestinationState));
}
public void NoMatchingGuard(
AsyncPassiveStateMachine <int, int> machine)
{
bool declined = false;
"establish state machine with no matching guard".x(async() =>
{
machine = new AsyncPassiveStateMachine <int, int>();
var currentStateExtension = new CurrentStateExtension();
machine.AddExtension(currentStateExtension);
machine.In(SourceState)
.On(Event)
.If(() => Task.FromResult(false)).Goto(ErrorState);
machine.TransitionDeclined += (sender, e) => declined = true;
await machine.Initialize(SourceState);
await machine.Start();
});
"when an event is fired".x(()
=> machine.Fire(Event));
"it should notify about declined transition".x(()
=> declined.Should().BeTrue("TransitionDeclined event should be fired"));
}
public void MatchingGuard(
AsyncPassiveStateMachine <int, int> machine,
CurrentStateExtension currentStateExtension)
{
"establish a state machine with guarded transitions".x(async() =>
{
machine = new AsyncPassiveStateMachine <int, int>();
currentStateExtension = new CurrentStateExtension();
machine.AddExtension(currentStateExtension);
machine.In(SourceState)
.On(Event)
.If(() => false).Goto(ErrorState)
.If(async() => await Task.FromResult(false)).Goto(ErrorState)
.If(async() => await Task.FromResult(true)).Goto(DestinationState)
.If(() => true).Goto(ErrorState)
.Otherwise().Goto(ErrorState);
await machine.Initialize(SourceState);
await machine.Start();
});
"when an event is fired".x(()
=> machine.Fire(Event));
"it should take transition guarded with first matching guard".x(()
=> currentStateExtension.CurrentState.Should().Be(DestinationState));
}
public void Loading(
StateMachineSaver <State> saver,
StateMachineLoader <State> loader,
FakeExtension extension,
State sourceState,
State targetState)
{
"establish a saved state machine with history"._(async() =>
{
var machine = new AsyncPassiveStateMachine <State, Event>();
DefineMachine(machine);
await machine.Initialize(State.A);
await machine.Start();
await machine.Fire(Event.S2); // set history of super state S
await machine.Fire(Event.B); // set current state to B
saver = new StateMachineSaver <State>();
loader = new StateMachineLoader <State>();
await machine.Save(saver);
});
"when state machine is loaded"._(async() =>
{
loader.SetCurrentState(saver.CurrentStateId);
loader.SetHistoryStates(saver.HistoryStates);
extension = new FakeExtension();
var loadedMachine = new AsyncPassiveStateMachine <State, Event>();
loadedMachine.AddExtension(extension);
DefineMachine(loadedMachine);
await loadedMachine.Load(loader);
loadedMachine.TransitionCompleted += (sender, args) =>
{
sourceState = args.StateId;
targetState = args.NewStateId;
};
await loadedMachine.Start();
await loadedMachine.Fire(Event.S);
});
"it should reset current state"._(() =>
sourceState.Should().Be(State.B));
"it should reset all history states of super states"._(() =>
targetState.Should().Be(State.S2));
"it should notify extensions"._(()
=> extension.LoadedCurrentState
.Should().BeEquivalentTo(State.B));
}
public void CommonAncestor(
AsyncPassiveStateMachine <int, int> machine)
{
const int commonAncestorState = 0;
const int sourceState = 1;
const int parentOfSourceState = 2;
const int siblingOfSourceState = 3;
const int destinationState = 4;
const int parentOfDestinationState = 5;
const int siblingOfDestinationState = 6;
const int Event = 0;
bool commonAncestorStateLeft = false;
"establish a hierarchical state machine"._(async() =>
{
machine = new AsyncPassiveStateMachine <int, int>();
machine.DefineHierarchyOn(commonAncestorState)
.WithHistoryType(HistoryType.None)
.WithInitialSubState(parentOfSourceState)
.WithSubState(parentOfDestinationState);
machine.DefineHierarchyOn(parentOfSourceState)
.WithHistoryType(HistoryType.None)
.WithInitialSubState(sourceState)
.WithSubState(siblingOfSourceState);
machine.DefineHierarchyOn(parentOfDestinationState)
.WithHistoryType(HistoryType.None)
.WithInitialSubState(destinationState)
.WithSubState(siblingOfDestinationState);
machine.In(sourceState)
.On(Event).Goto(destinationState);
machine.In(commonAncestorState)
.ExecuteOnExit(() => commonAncestorStateLeft = true);
await machine.Initialize(sourceState);
await machine.Start();
});
"when firing an event resulting in a transition with a common ancestor"._(()
=> machine.Fire(Event));
"the state machine should remain inside common ancestor state"._(()
=> commonAncestorStateLeft
.Should().BeFalse());
}
public void BeforeExecutingEntryActionsHierarchical(
AsyncPassiveStateMachine<string, string> machine,
IExtension<string, string> extension)
{
"establish an extension".x(()
=> extension = A.Fake<IExtension<string, string>>());
"establish a hierarchical state machine using the extension".x(async () =>
{
machine = new AsyncPassiveStateMachine<string, string>(Name);
machine.AddExtension(extension);
machine.DefineHierarchyOn("A")
.WithHistoryType(HistoryType.None)
.WithInitialSubState("A0");
machine.In("0")
.On("A0").Goto("A0");
await machine.Initialize("0");
await machine.Start();
});
"when firing an event onto the state machine".x(()
=> machine.Fire("A0"));
"it should call EnteringState on registered extensions for entered super states of target state".x(()
=> A.CallTo(() => extension.EnteringState(
A<IStateMachineInformation<string, string>>.That.Matches(x => x.Name == Name && x.CurrentStateId == "A0"),
A<IState<string, string>>.That.Matches(x => x.Id == "A"),
A<ITransitionContext<string, string>>.That.Matches(x => x.EventId.Value == "A0")))
.MustHaveHappened());
"it should call EnteringState on registered extensions for entered leaf target state".x(()
=> A.CallTo(() => extension.EnteringState(
A<IStateMachineInformation<string, string>>.That.Matches(x => x.Name == Name && x.CurrentStateId == "A0"),
A<IState<string, string>>.That.Matches(x => x.Id == "A0"),
A<ITransitionContext<string, string>>.That.Matches(x => x.EventId.Value == "A0")))
.MustHaveHappened());
}
public void LoadingAnInitializedStateMachine(
IAsyncStateMachine <string, int> machine,
Exception receivedException)
{
"establish an initialized state machine"._(() =>
{
machine = new AsyncPassiveStateMachine <string, int>();
machine.Initialize("initial");
});
"when state machine is loaded"._(async() =>
{
receivedException = await Catch.Exception(async() => await machine.Load(A.Fake <IAsyncStateMachineLoader <string> >()));
});
"it should throw invalid operation exception"._(() =>
{
receivedException.Should().BeOfType <InvalidOperationException>();
receivedException.Message.Should().Be(ExceptionMessages.StateMachineIsAlreadyInitialized);
});
}
public void NoCommonAncestor(
AsyncPassiveStateMachine <string, int> machine)
{
const string sourceState = "SourceState";
const string parentOfSourceState = "ParentOfSourceState";
const string siblingOfSourceState = "SiblingOfSourceState";
const string destinationState = "DestinationState";
const string parentOfDestinationState = "ParentOfDestinationState";
const string siblingOfDestinationState = "SiblingOfDestinationState";
const string grandParentOfSourceState = "GrandParentOfSourceState";
const string grandParentOfDestinationState = "GrandParentOfDestinationState";
const int Event = 0;
var log = string.Empty;
"establish a hierarchical state machine"._(async() =>
{
machine = new AsyncPassiveStateMachine <string, int>();
machine.DefineHierarchyOn(parentOfSourceState)
.WithHistoryType(HistoryType.None)
.WithInitialSubState(sourceState)
.WithSubState(siblingOfSourceState);
machine.DefineHierarchyOn(parentOfDestinationState)
.WithHistoryType(HistoryType.None)
.WithInitialSubState(destinationState)
.WithSubState(siblingOfDestinationState);
machine.DefineHierarchyOn(grandParentOfSourceState)
.WithHistoryType(HistoryType.None)
.WithInitialSubState(parentOfSourceState);
machine.DefineHierarchyOn(grandParentOfDestinationState)
.WithHistoryType(HistoryType.None)
.WithInitialSubState(parentOfDestinationState);
machine.In(sourceState)
.ExecuteOnExit(() => log += "exit" + sourceState)
.On(Event).Goto(destinationState);
machine.In(parentOfSourceState)
.ExecuteOnExit(() => log += "exit" + parentOfSourceState);
machine.In(destinationState)
.ExecuteOnEntry(() => log += "enter" + destinationState);
machine.In(parentOfDestinationState)
.ExecuteOnEntry(() => log += "enter" + parentOfDestinationState);
machine.In(grandParentOfSourceState)
.ExecuteOnExit(() => log += "exit" + grandParentOfSourceState);
machine.In(grandParentOfDestinationState)
.ExecuteOnEntry(() => log += "enter" + grandParentOfDestinationState);
await machine.Initialize(sourceState);
await machine.Start();
});
"when firing an event resulting in a transition without a common ancestor"._(()
=> machine.Fire(Event));
"it should execute exit action of source state"._(() =>
log.Should().Contain("exit" + sourceState));
"it should execute exit action of parents of source state (recursively)"._(()
=> log
.Should().Contain("exit" + parentOfSourceState)
.And.Contain("exit" + grandParentOfSourceState));
"it should execute entry action of parents of destination state (recursively)"._(()
=> log
.Should().Contain("enter" + parentOfDestinationState)
.And.Contain("enter" + grandParentOfDestinationState));
"it should execute entry action of destination state"._(()
=> log.Should().Contain("enter" + destinationState));
"it should execute actions from source upwards and then downwards to destination state"._(() =>
{
string[] states =
{
sourceState,
parentOfSourceState,
grandParentOfSourceState,
grandParentOfDestinationState,
parentOfDestinationState,
destinationState
};
var statesInOrderOfAppearanceInLog = states
.OrderBy(s => log.IndexOf(s.ToString(CultureInfo.InvariantCulture), StringComparison.Ordinal));
statesInOrderOfAppearanceInLog
.Should().Equal(states);
});
}
public void ExecutingTransition(
AsyncPassiveStateMachine <int, int> machine,
string actualParameter,
string asyncActualParameter,
bool exitActionExecuted,
bool entryActionExecuted,
bool asyncExitActionExecuted,
bool asyncEntryActionExecuted)
{
"establish a state machine with transitions"._(async() =>
{
machine = new AsyncPassiveStateMachine <int, int>();
machine.AddExtension(CurrentStateExtension);
machine.In(SourceState)
.ExecuteOnExit(() => exitActionExecuted = true)
.ExecuteOnExit(async() =>
{
asyncExitActionExecuted = true;
await Task.Yield();
})
.On(Event).Goto(DestinationState)
.Execute((string p) => actualParameter = p)
.Execute(async(string p) =>
{
asyncActualParameter = p;
await Task.Yield();
});
machine.In(DestinationState)
.ExecuteOnEntry(() => entryActionExecuted = true)
.ExecuteOnEntry(async() =>
{
asyncEntryActionExecuted = true;
await Task.Yield();
});
await machine.Initialize(SourceState);
await machine.Start();
});
"when firing an event onto the state machine"._(()
=> machine.Fire(Event, Parameter));
"it should execute transition by switching state"._(()
=> CurrentStateExtension.CurrentState.Should().Be(DestinationState));
"it should execute synchronous transition actions"._(()
=> actualParameter.Should().NotBeNull());
"it should execute asynchronous transition actions"._(()
=> asyncActualParameter.Should().NotBeNull());
"it should pass parameters to transition action"._(()
=> actualParameter.Should().Be(Parameter));
"it should execute synchronous exit action of source state"._(()
=> exitActionExecuted.Should().BeTrue());
"it should execute asynchronous exit action of source state"._(()
=> asyncExitActionExecuted.Should().BeTrue());
"it should execute synchronous entry action of destination state"._(()
=> entryActionExecuted.Should().BeTrue());
"it should execute asynchronous entry action of destination state"._(()
=> asyncEntryActionExecuted.Should().BeTrue());
}
public GossipManager(GossipNode gossipNode)
{
_gossipNode = gossipNode;
_cts = new CancellationTokenSource();
_currentStateExtension = new CurrentStateExtension();
_requests = new ConcurrentDictionary <string, BaseMessage>();
_helloTimer = new Timer(new TimerCallback(HelloTimerHandle));
_heartbeatTimer = new Timer(new TimerCallback(HeartbeatTimerHandle));
_fsm = new AsyncPassiveStateMachine <NodeState, GossipEvent>("GossipManager");
_fsm.AddExtension(new ConsoleLogExtension());
_fsm.AddExtension(_currentStateExtension);
_fsm.Initialize(NodeState.Initialized);
_fsm.In(NodeState.Initialized)
.On(GossipEvent.HelloSend)
.Goto(NodeState.HelloSent)
.Execute(async() =>
{
// set hello timer
await SendHello();
});
_fsm.In(NodeState.HelloSent)
.On(GossipEvent.HelloAnswer)
.Goto(NodeState.Infected)
.Execute <HelloResponse>((msg) =>
{
ReceiveHelloAnswer(msg);
})
.On(GossipEvent.HelloExpired)
.Goto(NodeState.Initialized)
.Execute(async() =>
{
// hello timer re-set
await SendHello();
});
_fsm.In(NodeState.Infected)
.On(GossipEvent.HeartbeatExpired)
.Goto(NodeState.Susceptible)
.Execute(async() =>
{
await SendHeartbeat();
})
.On(GossipEvent.HeartbeatAnswer)
.Goto(NodeState.Infected)
.Execute <HeartbeatResponse>((msg) => {
IGossipPeer senderPeer = msg.Members?.FirstOrDefault();
MergeLists(senderPeer, msg.Members);
});
_fsm.In(NodeState.Infected)
.On(GossipEvent.HelloReceive)
.Execute <HelloRequest>(async(msg) =>
{
await SendHelloAnswer(msg);
});
_fsm.In(NodeState.Susceptible)
.On(GossipEvent.HelloReceive)
.Execute <HelloRequest>(async(msg) =>
{
await SendHelloAnswer(msg);
})
.On(GossipEvent.HeartbeatReceive)
.If <HeartbeatRequest>((msg) =>
{
return(_gossipNode.GossipPeer.Heartbeat < msg.Peer.Heartbeat);
})
.Goto(NodeState.Infected)
.Execute <HeartbeatRequest>(async(msg) =>
{
await ReceiveHeartbeat(msg);
})
.On(GossipEvent.HeartbeatAnswer)
.If <HeartbeatResponse>((msg) =>
{
return(msg.Members[0].Heartbeat > _gossipNode.GossipPeer.Heartbeat);
}).Goto(NodeState.Infected);
_fsm.Start();
}