/// <summary>
/// Checks the parallelism of two transitions in a petrinet recursively
/// In some petrinets with a high complexity
/// </summary>
/// <param name="transition1">Eventname of y-direction</param>
/// <param name="transition2">Eventname of x-direction</param>
/// <param name="petriNet">Petrinet</param>
/// <returns>Return true if the two transitions are parallel</returns>
/// <autor>Andrej Albrecht</autor>
// ReSharper disable once UnusedMember.Local
private static bool CheckTransitionIsParallel(string transition1, string transition2, PetriNet petriNet)
{
Transition transitionY = petriNet.FindTransition(transition1);
Transition transitionX = petriNet.FindTransition(transition2);
return(CheckTransitionIsParallel(transitionY, transitionX, petriNet));
}
/// <summary>
/// Returns a list of places between two transitions in a petrinet
/// </summary>
/// <param name="t1">Transitionname</param>
/// <param name="t2">Transitionname</param>
/// <param name="petriNet">Petrinet</param>
/// <returns>Returns a list of places</returns>
/// <autor>Andrej Albrecht</autor>
private List <Place> GetListOfPlacesBetweenTwoTransitionsFromPetriNet(string t1, string t2, PetriNet petriNet)
{
Transition transition1 = petriNet.FindTransition(t1);
Transition transition2 = petriNet.FindTransition(t2);
HashSet <Place> placesInBetween = new HashSet <Place>();
foreach (Place outgoingPlace in transition1.OutgoingPlaces)
{
if (transition2.IncomingPlaces.Contains(outgoingPlace))
{
placesInBetween.Add(outgoingPlace);
}
}
return(placesInBetween.ToList());
}
/// <summary>
/// Adds a place and the transitions it leads to.
/// </summary>
/// <param name="startingTransition">>Contains the starting transition</param>
/// <param name="followers">node.followers</param>
/// <param name="petriNet">Contains the current petri net</param>
/// <returns>The two transitions that are in an XOR-relation.</returns>
/// <author>Jannik Arndt</author>
public List <Transition> StartXOR(Transition startingTransition, List <EventNode> followers, PetriNet petriNet)
{
if (followers.Count > 1)
{
for (var index = 0; index < followers.Count; index++)
{
_openParallelismCount.Push(Parallelism.Xor);
}
}
var newPlace = petriNet.AddPlace();
var listOfFollowingTransitions = new List <Transition>();
foreach (var eventNode in followers)
{
if (eventNode == null)
{
break;
}
/* _____________________ __________ ____________________________
* | startingTransition | ---> ( NewPlace ) ---> | NewFollowingTransition |
* ''''''''''''''''''''' ********** ''''''''''''''''''''''''''''
*/
var newFollowingTransition = petriNet.FindTransition(eventNode.InnerEvent.Name);
// The following transition already exists => close something
if (newFollowingTransition != null)
{
if (_openParallelismCount.Count > 0)
{
switch (_openParallelismCount.Peek())
{
// Close XOR
case Parallelism.Xor:
newFollowingTransition.IncomingPlaces.Remove(newPlace);
startingTransition.AddOutgoingPlace(newFollowingTransition.IncomingPlaces.First());
_openParallelismCount.Pop();
break;
// Close AND
case Parallelism.And:
newFollowingTransition.AddIncomingPlace(newPlace);
startingTransition.AddOutgoingPlace(newPlace);
_openParallelismCount.Pop();
break;
}
}
}
// Open XOR
else
{
newFollowingTransition = petriNet.AddTransition(eventNode.InnerEvent.Name, incomingPlace: newPlace);
if (newPlace.IncomingTransitions.Count == 0)
{
startingTransition.AddOutgoingPlace(newPlace);
}
}
listOfFollowingTransitions.Add(newFollowingTransition);
}
if (newPlace.IncomingTransitions.Count == 0 && newPlace.OutgoingTransitions.Count == 0)
{
petriNet.Places.Remove(newPlace);
}
return(listOfFollowingTransitions);
}
