[QPIDJMS-251] Thread unsafe use of MessageListener and state variable in JmsMessageConsumer

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.11.1
• Fix Version/s: 0.20.0
• Component/s: qpid-jms-client
• Assignee: Timothy A. Bish
• Reporter: Timothy A. Bish
• Created: 13/Jan/17 18:04
• Updated: 20/Jan/17 18:53
• Resolved: 13/Jan/17 19:03

Description

The assignment of the MessageListener in the MessageConsumer class is done to a non-volatile value that can result in the initial run of the message dispatch thread missing the value and delay dispatch. Likewise the code uses a state variable to track started state but the value is not accessed in a thread safe way and the state can be missed. The started value is unnecessary as the internal message queue instance maintains a thread safe running state that can be used for the same information.