[
https://issues.apache.org/jira/browse/AMQNET-342?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Jim Gomes resolved AMQNET-342.
------------------------------
Resolution: Fixed
Fix Version/s: 1.6.0
1.5.2
Added call to lock SyncRoot that was missing when iterating over the consumer
list.
> "Collection was modified" exception when adding message consumer
> ----------------------------------------------------------------
>
> Key: AMQNET-342
> URL: https://issues.apache.org/jira/browse/AMQNET-342
> Project: ActiveMQ .Net
> Issue Type: Bug
> Components: NMS
> Affects Versions: 1.5.1
> Environment: Windows XP
> Reporter: Andrew Parkin
> Assignee: Jim Gomes
> Fix For: 1.5.2, 1.6.0
>
> Attachments: consumercreator output.jpg, consumercreator.cs
>
>
> I am occasionally seeing the exception below when executing the following
> code:
> IMessageConsumer consumer = session.CreateConsumer(dest);
> consumer.Listener += BufferMessage;
> System.InvalidOperationException: Collection was modified; enumeration
> operation may not execute.
> at System.Collections.Hashtable.HashtableEnumerator.MoveNext()
> at Apache.NMS.ActiveMQ.Session.Start()
> at Apache.NMS.ActiveMQ.MessageConsumer.add_Listener(MessageListener value)
> Putting locks around the code in my application doesn't prevent the problem.
> I've had a look at the ActiveMQ source & I suspect the problem is as follows:
> MessageConsumer invokes the following code in the "add" section of "public
> event MessageListener Listener"
> if(wasStarted == true)
> {
> this.session.Start();
> }
> ...and Session.Start() iterates over consumers.values as follows:
> foreach(MessageConsumer consumer in this.consumers.Values)
> {
> consumer.Start();
> }
> I noticed that everywhere else in Session where this iteration occurs is
> locked with "lock(this.consumers.SyncRoot)", except for in the Start()
> method. Does a lock also need to be put around this section as well?
> Unfortunately I'm having problems building the source at the moment so I'm
> unable to confirm whether this would fix the problem or not.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
