[OAK-1290] ObservationManager#removeEventListener prone to deadlocks

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.14
• Component/s: jcr
• Labels: observation
• Assignee: Michael Dürig
• Reporter: Michael Dürig
• Created: 16/Dec/13 11:03
• Updated: 13/Jan/14 13:05
• Resolved: 17/Dec/13 10:38

Description

The contract for ObservationManager#removeEventListener mandates: "A listener may be deregistered while it is being executed. The deregistration method will block until the listener has completed executing."

However a strict implementation of this contract is prone to deadlocks: clients unregistering event listeners need to take care not to hold a lock that is also acquired from the event listener being unregistered as this will lead to a deadlock

Issue Links

• relates to: OAK-1176 ObservationTest#observationDispose fails every now and then