Given: A consumer with byte credit N for a queue with messages Big size > N and Small size < N
The consumer should not be able to consume Big. Now remove Big with a different consumer.
The consumer should now be able to consume Small, but doesn't
The problem in Queue.cpp is twofold:
- if a consumer returns "false" from accept, it is assumed to be blocked and is removed from the listener set. It won't be notified of new messages
- the queue only notifies when new messages arrive. It does not notify when a blocking message is removed.
This is demonstrated by adding the following to test_credit_flow_bytes in message.py:
- Check for bug that allowed a small message to be hidden by a larger one.
session.message_flow(unit = session.credit_unit.byte, value = msg_size, destination = "c")
q.get(timeout = 1) # Should fail, message is too big.
self.fail("Expected Empty exception")
except Empty: None
- Create another consumer to remove the large message
session.message_subscribe(queue = "q", destination = "c2")
session.message_flow(unit = session.credit_unit.byte, value = 0xFFFFFFFFL, destination = "c2")
session.message_flow(unit = session.credit_unit.message, value = 1, destination = "c2")
self.assertDataEquals(session, session.incoming("c2").get(timeout=1), "toobigtoobigtoobigtoobig")
- Now the first consumer should be able to receive the smaller message.
self.assertDataEquals(session, q.get(timeout = 1), "abcdefgh")