public StateMachine(string name, IAbstractLogger logger, StateDef <TState> stateDef, Dictionary <TState, TransitionDef <TState>[]> transitionMap, bool logTransitions = true)
{
if (logger == null)
{
throw new ArgumentNullException("logger");
}
_logger = logger;
_stateTransitions = new Dictionary <TState, TransitionDef <TState>[]>();
_logTransitions = logTransitions;
foreach (var kv in transitionMap)
{
TransitionDef <TState>[] tmp = (TransitionDef <TState>[])kv.Value.Clone();
Array.Sort <TransitionDef <TState> >(tmp);
_stateTransitions.Add(kv.Key, tmp);
}
_state = stateDef;
Name = name;
}
public StateMachineBuilder <TState> UseStateDef(StateDef <TState> def)
{
_stateDef = def;
return(this);
}
public async Task <TState> Transit(TState newState, CancellationToken cts, object args = null)
{
if (_logTransitions)
{
_logger.Info("Machine '{0}' is about to transit {1} --> {2}", Name, State, newState);
}
if (!StateDef <TState> .IsValid(newState))
{
return(await compliteWithError(new Exception(string.Format("State '{0}' is invalid for machine '{1}'", newState, Name))));
}
if (IsInFinalState)
{
return(await compliteWithError(new Exception(string.Format("Machine '{0}' can't transit to state '{1}' because it is in final state '{2}'", Name, newState, _state.Final))));
}
int res = Interlocked.Exchange(ref _isInTransition, 1); //блокировка транзишенов до тех пор, пока не заевршится текущий транзишен
if (res != 0)
{
if (EqualityComparer <TState> .Default.Equals(newState, FinalState)) //разрешаем только рекурсивный Close
{
_logger.Warn("Machine '{0}' started reqursive transition {1} --> {2}", Name, State, newState);
}
else
{
return(await compliteWithError(new Exception(string.Format("In machine '{0}' reqursive transition {1} --> {2} has been detected", Name, State, newState))));
}
}
TState transitionResult = State;
CancellationTokenRegistration reg = default(CancellationTokenRegistration);
bool lockCleared = false;
try {
TState stateFrom = State;
TransitionDef <TState> transition = getTransition(stateFrom, newState);
if (transition == TransitionDef <TState> .Empty)
{
throw new Exception(string.Format("Machine '{0}' didn't find transition {1} --> {2}", Name, stateFrom, newState));
}
if (_logTransitions)
{
_logger.Info("Machine '{0}' is transiting {1} --> {2}", Name, stateFrom, newState);
}
if (transition.StateActivityAsync != null)
{
try {
TransitionState = _state.GetTransitionalState(State, newState);
if (TransitionState != null)
{
onStateChanging(TransitionState.Value);
}
reg = cts.Register(() => { lockCleared = true; Interlocked.Exchange(ref _isInTransition, 0); });
transitionResult = await transition.StateActivityAsync(stateFrom, newState, cts, args).WithAllExceptions().ConfigureAwait(false);
cts.ThrowIfCancellationRequested();
State = transitionResult;
if (_logTransitions)
{
_logger.Info("Machine '{0}' transited {1} --> {2}", Name, stateFrom, newState);
}
onStateChanged(stateFrom, transitionResult);
}
catch (AggregateException ex)
{
_logger.Error("Machine '{0}' failed to transit {1} --> {2}", Name, stateFrom, newState);
onStateChanged(stateFrom, transitionResult, ex);
ex.Handle((err) => {
if (err is OperationCanceledException)
{
_logger.Warn("Machine '{0}' transition {1} --> {2} was cancelled", Name, stateFrom, newState);
return(true);
}
return(false);
});
}
catch (OperationCanceledException ce)
{
_logger.Warn("Machine '{0}' transition {1} --> {2} was cancelled", Name, stateFrom, newState);
onStateChanged(stateFrom, transitionResult, ce);
}
catch (Exception ex)
{
_logger.Exception(string.Format("Machine '{0}' failed to transit {1} --> {2}", Name, stateFrom, newState), ex);
onStateChanged(stateFrom, transitionResult, ex);
throw;
}
}
else
{
State = newState;
transitionResult = newState;
if (_logTransitions)
{
_logger.Info("Machine '{0}' transited {1} --> {2} with no action", Name, stateFrom, newState);
}
onStateChanged(stateFrom, newState);
}
}
finally {
if (!lockCleared)
{
Interlocked.Exchange(ref _isInTransition, 0);
TransitionState = null;
}
}
return(transitionResult);
}
