Fixes #1652: Avoid repeated closing of receiver which could hang the …

…test

tests/system_tests_stuck_deliveries.py

@@ -163,21 +163,30 @@ def __init__(self, sender_host, receiver_host, query_host, addr, dlv_count, stuc
         self.receiver_conn  = None
         self.query_conn     = None
         self.error          = None
+        self.timer          = None
+        self.poll_timer     = None
+        self.receiver       = None
+        self.reply_receiver = None
+        self.proxy          = None
+        self.query_sender   = None
+        self.reply_addr     = None
+        self.sender         = None
+        self.link_closed    = False
         self.n_tx           = 0
         self.n_rx           = 0
         self.expected_stuck = 0
-        self.last_stuck     = 0
+        self.deliveries_stuck = 0
 
     def timeout(self):
-        self.error = "Timeout Expired - n_tx=%d, n_rx=%d, expected_stuck=%d last_stuck=%d" %\
-            (self.n_tx, self.n_rx, self.expected_stuck, self.last_stuck)
+        self.error = "Timeout Expired - n_tx=%d, n_rx=%d, expected_stuck=%d deliveries_stuck=%d" %\
+            (self.n_tx, self.n_rx, self.expected_stuck, self.deliveries_stuck)
         self.sender_conn.close()
         self.receiver_conn.close()
         self.query_conn.close()
         if self.poll_timer:
             self.poll_timer.cancel()
 
-    def fail(self, error):
+    def stop_test(self, error):
         self.error = error
         self.sender_conn.close()
         self.receiver_conn.close()
@@ -188,7 +197,6 @@ def fail(self, error):
 
     def on_start(self, event):
         self.timer          = event.reactor.schedule(TIMEOUT, TestTimeout(self))
-        self.poll_timer     = None
         self.receiver_conn  = event.container.connect(self.receiver_host)
         self.query_conn     = event.container.connect(self.query_host)
         self.receiver       = event.container.create_receiver(self.receiver_conn, self.addr)
@@ -209,8 +217,7 @@ def on_link_opened(self, event):
             # is caused due to the first test failure, so this fix will
             # fix the second failure
             self.sender_conn = event.container.connect(self.sender_host)
-            self.sender = event.container.create_sender(self.sender_conn,
-                                                        self.addr)
+            self.sender = event.container.create_sender(self.sender_conn, self.addr)
 
     def on_sendable(self, event):
         if event.sender == self.sender:
@@ -230,19 +237,25 @@ def on_message(self, event):
         elif event.receiver == self.reply_receiver:
             response = self.proxy.response(event.message)
             self.accept(event.delivery)
-            self.last_stuck = response.results[0].deliveriesStuck
-            if self.last_stuck == self.expected_stuck:
-                if self.close_link:
-                    self.receiver.close()
-                else:
-                    for dlv in self.stuck_dlvs:
-                        self.accept(dlv)
-                    self.stuck_dlvs = []
+            self.deliveries_stuck = response.results[0].deliveriesStuck
+            if self.deliveries_stuck == self.expected_stuck:
+                # The deliveries stuck queried via management equals what we expected.
+                # The test has passed.
+                if self.expected_stuck != 0:
+                    if self.close_link:
+                        self.receiver.close()
+                    else:
+                        for dlv in self.stuck_dlvs:
+                            self.accept(dlv)
+                # Once the deliveries have been accepted, we want to make sure that the number of stuck deliveries
+                # is back to zero before we quit this test.
                 if self.expected_stuck > 0:
                     self.query_stats(0)
                 else:
-                    self.fail(None)
+                    self.stop_test(None)
             else:
+                # The deliveries stuck queried via management is not what we expected.
+                # We will keep querying until TIMEOUT seconds to see if our condition comes True.
                 self.poll_timer = event.reactor.schedule(0.5, PollTimeout(self))
 
     def query_stats(self, expected_stuck):