changes so that the system can run for infinite time and end when it gets empty

dream/simulation/CapacityStationController.py

@@ -49,13 +49,15 @@ class CapacityStationController(EventGenerator):
             if self.stop:
                 if self.env.now>self.stop:
                     break
+            # activate the main loop
             self.env.process(self.steps())
+            # wait until the main loop is completed
             yield self.stepsAreComplete
             self.stepsAreComplete=self.env.event()
             yield self.env.timeout(self.interval)       #wait for the predetermined interval
 
+    # the main loop that is carried in every interval  
     def steps(self):
-
         # loop through the stations
         for station in G.CapacityStationList:
             exit=station.next[0]  # take the exit
@@ -72,6 +74,11 @@ class CapacityStationController(EventGenerator):
             # lock the exit again
             exit.isLocked=True
         
+        # if the last exits led to an empty system then the simulation must be stopped
+        # step returns and the generator never yields the stepsAreComplete signal
+        if self.checkIfSystemEmpty():
+            return
+        
         # create the entities in the following stations
         self.createInCapacityStationBuffers()
         # if there is need to merge entities in a buffer
@@ -84,6 +91,7 @@ class CapacityStationController(EventGenerator):
         # and set the flags to the entities of StationBuffers 
         self.calculateWhatIsToBeProcessed()
     
+        # move the entities into the stations
         # loop through the stations
         for station in G.CapacityStationList:
             station.isLocked=False      # unlock the station
@@ -104,13 +112,9 @@ class CapacityStationController(EventGenerator):
         # for every station update the remaining interval capacity so that it is ready for next loop
         for station in G.CapacityStationList:
             station.remainingIntervalCapacity.pop(0)                       
-        self.stepsAreComplete.succeed()    
             
-    def checkIfStationsEmpty(self):
-        for station in G.CapacityStationList:
-            if len(station.getActiveObjectQueue()):
-                return False
-        return True        
+        # send message that the main loop is completed    
+        self.stepsAreComplete.succeed()         
 
     # invoked after entities have exited one station to create 
     # the corresponding entities to the following buffer     
@@ -213,9 +217,10 @@ class CapacityStationController(EventGenerator):
                 import Globals
                 Globals.setWIP([entityToCreate])     #set the new components as wip                                            
     
-                    
-    def checkIfBufferFinished(self, buffer):
-        if buffer.getActiveObjectQueue():
+    # checks if the system is empty so that the simulation can be stopped
+    def checkIfSystemEmpty(self):
+        for object in G.CapacityStationList+G.CapacityStationBufferList+G.CapacityStationExitList:
+            if len(object.getActiveObjectQueue()):
                 return False
         return True
         
\ No newline at end of file

dream/simulation/LineGenerationJSON.py

@@ -817,6 +817,7 @@ def createObjects():
             nextCapacityStationBufferId=element.get('nextCapacityStationBufferId', None)
             CE=CapacityStationExit(id,name,nextCapacityStationBufferId=nextCapacityStationBufferId)
             G.CapacityStationExitList.append(CE)
+            G.ExitList.append(CE)
             G.ObjList.append(CE)
              
     # -----------------------------------------------------------------------