Add queueing example model

examples/queueing/processor.py

@@ -0,0 +1,46 @@
+from pypdevs.DEVS import AtomicDEVS
+
+# Define the state of the processor as a structured object
+class ProcessorState(object):
+    def __init__(self):
+        # State only contains the current event
+        self.evt = None
+
+class Processor(AtomicDEVS):
+    def __init__(self, nr, proc_param):
+        AtomicDEVS.__init__(self, "Processor_%i" % nr)
+
+        self.state = ProcessorState()
+        self.in_proc = self.addInPort("in_proc")
+        self.out_proc = self.addOutPort("out_proc")
+        self.out_finished = self.addOutPort("out_finished")
+
+        # Define the parameters of the model
+        self.speed = proc_param
+        self.nr = nr
+
+    def intTransition(self):
+        # Just clear processing event
+        self.state.evt = None
+        return self.state
+
+    def extTransition(self, inputs):
+        # Received a new event, so start processing it
+        self.state.evt = inputs[self.in_proc]
+        # Calculate how long it will be processed
+        time = 20.0 + max(1.0, self.state.evt.size / self.speed)
+        self.state.evt.processing_time = time
+        return self.state
+
+    def timeAdvance(self):
+        if self.state.evt:
+            # Currently processing, so wait for that
+            return self.state.evt.processing_time
+        else:
+            # Idle, so don't do anything
+            return float('inf')
+
+    def outputFnc(self):
+        # Output the processed event and signal as finished
+        return {self.out_proc: self.state.evt,
+                self.out_finished: self.nr}