implement service discipline when customer arrives

Author: geraintpalmer

ciw/node.py

@@ -140,19 +140,24 @@ def begin_service_if_possible_accept(self, next_individual):
             next_individual.reneging_date = self.get_reneging_date(next_individual)
         self.decide_class_change(next_individual)
 
-        free_server = self.find_free_server(next_individual)
+        if isinf(self.c):
+            ind = next_individual
+        else:
+            ind = self.choose_next_customer()
+        
+        free_server = self.find_free_server(ind)
         if free_server is None and isinf(self.c) is False and self.c > 0:
-            self.decide_preempt(next_individual)
+            self.decide_preempt(ind)
         if free_server is not None or isinf(self.c):
             if isinf(self.c) is False:
-                self.attach_server(free_server, next_individual)
-            next_individual.service_start_date = self.now
-            next_individual.service_time = self.get_service_time(next_individual)
-            next_individual.service_end_date = self.now + next_individual.service_time
+                self.attach_server(free_server, ind)
+            ind.service_start_date = self.now
+            ind.service_time = self.get_service_time(ind)
+            ind.service_end_date = self.now + ind.service_time
             self.number_in_service += 1
-            self.reset_class_change(next_individual)
+            self.reset_class_change(ind)
             if not isinf(self.c):
-                free_server.next_end_service_date = next_individual.service_end_date
+                free_server.next_end_service_date = ind.service_end_date
 
     def begin_interrupted_individuals_service(self, srvr):
         """

ciw/tests/test_node.py

@@ -628,6 +628,7 @@ def test_begin_service_if_possible_accept_method(self):
         self.assertEqual(ind.service_start_date, False)
         self.assertEqual(ind.service_end_date, False)
         Q.current_time = 300
+        Q.transitive_nodes[0].individuals[0].append(ind)
         Q.transitive_nodes[0].begin_service_if_possible_accept(ind)
         self.assertEqual(ind.arrival_date, 300)
         self.assertEqual(round(ind.service_time, 5), 0.03382)

ciw/tests/test_simulation.py

@@ -1172,8 +1172,8 @@ def test_service_in_random_order(self):
         Q = ciw.Simulation(N)
         Q.simulate_until_max_time(14)
         recs = sorted(Q.get_all_records(), key=lambda dr: dr.service_start_date)
-        self.assertEqual([r.id_number for r in recs], [1, 2, 5, 4, 8])
-        self.assertEqual([r.arrival_date for r in recs], [1.0, 2.0, 5.0, 4.0, 8.0])
+        self.assertEqual([r.id_number for r in recs], [1, 2, 5, 6, 4])
+        self.assertEqual([r.arrival_date for r in recs], [1.0, 2.0, 5.0, 6.0, 4.0])
         self.assertEqual([r.service_time for r in recs], [2.5, 2.5, 2.5, 2.5, 2.5])
         self.assertEqual(
             [r.service_end_date for r in recs],