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https://issues.apache.org/jira/browse/FELIX-4426?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14166720#comment-14166720
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Marcel Offermans commented on FELIX-4426:
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I'm not sure if it will affect us, but the contract for a ConcurrentHashMap is
rather vague when it comes to iterating over the collection while updating it:
Yes, the good news is that it will not throw an exception.
No, it is not guaranteed that you will see updates in the iterator. The
iterator reflects "the state of the hash table at some point at or since the
creation of the iterator/enumeration".
Will this be a problem? It depends. There is no "CopyOnWriteHashMap" which
would have a more determinate behaviour (namely guaranteeing that your
collection and therefore the iterator won't change after you've got hold of a
reference) but at the cost of more expensive modifications. We should think
this through, though, to advise our users when to use this, and when not to
(you can always use callbacks and a list implementation of choice if you need
more control).
> Allow DM to manage collections of services
> ------------------------------------------
>
> Key: FELIX-4426
> URL: https://issues.apache.org/jira/browse/FELIX-4426
> Project: Felix
> Issue Type: New Feature
> Components: Dependency Manager
> Affects Versions: dependencymanager-4.0.0
> Reporter: J.W. Janssen
> Assignee: Pierre De Rop
> Fix For: dependencymanager-4.0.0
>
>
> DM has great support for single-cardinality dependencies, allowing you to
> only declare the dependency as (volatile) field. For multiple-cardinality
> dependencies, no such support is present, forcing you to always manually
> implement this using callbacks.
> It would be great if I could declare multiple-cardinality dependencies like:
> {code}
> private volatile List<MyService> m_services;
> {code}
> and let DM manage the list for me.
> Note that you need some additional reflection mojo to obtain the actual
> collection type. An example of how this can work can be found in a utility
> class for Swagger in the Amdatu-Web project, see
> https://bitbucket.org/amdatu/amdatu-web/src/master/org.amdatu.web.rest/src/org/amdatu/web/rest/doc/swagger/SwaggerUtil.java?at=master#cl-304
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