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https://issues.apache.org/jira/browse/AMQ-6414?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15887825#comment-15887825
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Gary Tully commented on AMQ-6414:
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[~cshannon] I think it is ok as it is now, so long as we don't get a concurrent 
read which your initialized latch sorts.
If I get a chance to explore the auto scenario we can revisit.

> The nio+ssl transports can block and hang on connection in certain situations
> -----------------------------------------------------------------------------
>
>                 Key: AMQ-6414
>                 URL: https://issues.apache.org/jira/browse/AMQ-6414
>             Project: ActiveMQ
>          Issue Type: Bug
>          Components: Broker, Transport
>    Affects Versions: 5.14.0
>            Reporter: Christopher L. Shannon
>            Assignee: Christopher L. Shannon
>             Fix For: 5.14.1, 5.15.0
>
>
> The nio+ssl transports can hang on initial connection and never read from the 
> socket after the SSL handshake for certain conditions.  This behavior is most 
> evident when using the auto+nio+ssl transport for a network bridge between 2 
> brokers, however I also saw the issue for the normal nio+ssl transport when 
> running the NetworkAsyncStartTest and even the amqp+nio+ssl transport.
> After debugging I found that the issue is that the onSelect method of the 
> registered callback, which calls the serviceRead() method, is not always 
> getting triggered.  I believe that the root of the problem is that even 
> though a selector is registered with a SelectionKey.OP_READ, there is no 
> guarantee that the selected set is correct which is what the SelectorWorker 
> uses to detect if the operation is ready. The SelectionKey documentation 
> specifically states that the ready set is a hint but not a guarantee that the 
> channel is ready.  This seems to only effect the SSL transport (not normal 
> NIO), probably because a read selection was already done once to unwrap the 
> SSL transport
> More info: 
> https://docs.oracle.com/javase/8/docs/api/java/nio/channels/SelectionKey.html
> The fix for this is to trigger the selectRead() after the transport finishes 
> starting up.  (needs to be in a new thread specifically for OpenWire to allow 
> the wireformat negotiation to not block on startup).  This will work for the 
> SSL transport specifically since we know the transport is read to read from 
> the the channel after starting up.  We know this because the SSL handshake 
> already took place which means we've already read from the channel.



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