[FELIX-6161] SCR: Method of resolving references limits Service ListenerHook implementations

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: scr-2.1.16
• Fix Version/s: scr-2.1.22
• Component/s: Declarative Services (SCR)
• Assignee: Unassigned
• Reporter: Arnoud Glimmerveen
• Created: 14/Jul/19 18:35
• Updated: 24/Apr/20 12:50
• Resolved: 24/Apr/20 12:50

Description

When experimenting with creating a Service ListenerHook to realise a providing a service on demand pattern, I noticed that references from components managed by Felix SCR were not showing up as expected: When a reference declares a target filter, that target filter is not included in the ListenerInfo provided to the ListenerHook. As a consequence the ListenerHook is unable to create a matching service.

Source of the observed behaviour is how SCR tracks references, specifically that it opens a ServiceListener for just the className and performs the matching of the target filter inside the ServiceListener. This approach unfortunately hides the target filter from the Service ListenerHook and thus the Service ListenerHook will have insufficient information to create a matching service.

Also look at the discussion on the dev mailing list: https://www.mail-archive.com/[e-mail]/msg48657.html 

Issue Links

• links to: GitHub Pull Request #19