[QPID-7679] Memory leak in DirectExchange

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Resolved
• Affects Version/s: qpid-cpp-0.34, qpid-cpp-1.36.0
• Fix Version/s: qpid-cpp-1.37.0
• Component/s: C++ Broker
• Assignee: Clifford Jansen
• Reporter: Clifford Jansen
• Created: 21/Feb/17 17:58
• Updated: 22/Nov/17 09:57
• Resolved: 24/Feb/17 17:34

Description

The Exchange::unbind call for DirectExchange is coded assuming that the binding actually exists. If the binding does not exist, this has the side effect of creating a Bindingkey in the BindingKey map that remains in the map until broker exit. The management count of bindings is not updated so there is no indication there of the problem.

A well behaved 0_10 program that creates a queue, creates a direct binding, deletes the binding and then deletes the queue results in a second implicit unbind when the queue is deleted (usually on the QueueDeleteBody, but if an autodelete queue, it can also happen on the MessageCancelBody ending a subscription).

TopicExchange and FanOutExchange explicitly guard against non-existence of the binding/queue pair on unbind(). Presumably, DirectExchange should do the same. HeadersExchange doesn't check but doesn't "remember" the pair.