RFR: 8139965 - Hang seen when using com.sun.jndi.ldap.search.replyQueueSize

[Rob McKenna]

Thanks Daniel:

http://cr.openjdk.java.net/~robm/8139965/webrev.03/

I'm planning to follow up on the test side of things with a separate
bug. I think the technique used in some of the recent SQE LDAP tests
might be applicable.

    -Rob

On 05/09/18 09:53, Daniel Fuchs wrote:
> Hi Rob,
> 
> That looks better but I believe that:
> 
> 1. closed should be volatile since it's read from outside
>    synchronized block
> 
> 2. it seems there might be a race where the last response
>    received could be dropped, if the connection is closed
>    just after it's been pulled from the queue.
> 
> So I would suggest exchanging:
> 
>  115         if (isClosed()) {
>  116             return null;
>  117         }
>  118
>  119         return result;
> 
> with:
> 
>              return result == EOF ? null : result;
> 
> best regards,
> 
> -- daniel
> 
> On 05/09/2018 02:05, Rob McKenna wrote:
> > Thanks for the reviews folks.
> > 
> > I believe the following captures your recommended changes:
> > 
> > http://cr.openjdk.java.net/~robm/8139965/webrev.02/
> > 
> > W.r.t. testing I think this area has been difficult to test
> > traditionally. I'll have a dig through the existing testbase (and I'll
> > get back to you) to see if there's anything similar but afaik most tests
> > simply mimic a bindable dummy ldap server.
> > 
> > Vyom, are you aware of any more rigorous tests / ldap test frameworks?
> > 
> >      -Rob
> > 
> > On 04/09/18 10:22, Daniel Fuchs wrote:
> > > Hi Rob,
> > > 
> > > I concur with Chris.
> > > completed needs to be volatile and close() needs to
> > > set a flag and use offer like cancel().
> > > 
> > > The condition for testing for closed then becomes
> > > that the flag is set and the queue is empty or has EOF
> > > as its head.
> > > 
> > > Is there any way this could be tested by a regression
> > > test?
> > > 
> > > best regards,
> > > 
> > > -- daniel
> > > 
> > > On 04/09/2018 10:00, Chris Hegarty wrote:
> > > > Rob,
> > > > 
> > > > > On 3 Sep 2018, at 22:48, Rob McKenna <rob.mckenna at oracle.com> wrote:
> > > > > 
> > > > > Hi folks,
> > > > > 
> > > > > I'd like to get a re-review of this change:
> > > > > 
> > > > > https://bugs.openjdk.java.net/browse/JDK-8139965 <https://bugs.openjdk.java.net/browse/JDK-8139965>
> > > > 
> > > > This issue is closed as `will not fix`. I presume you will re-open it before pushing.
> > > > 
> > > > > http://cr.openjdk.java.net/~robm/8139965/webrev/ <http://cr.openjdk.java.net/~robm/8139965/webrev/>
> > > > 
> > > > 
> > > > 43     private boolean completed;
> > > > Won’t `completed` need to be volatile now? ( since the removal of synchronized from hasSearchCompleted )
> > > > 
> > > > LdapRequest.close puts EOF into the queue, but that is a potentially blocking operation ( while holding the lock ). If the queue is at capacity, then it will block forever. This model will only work if `getReplyBer` is always guaranteed to be running concurrently. Is it?
> > > > 
> > > > Please check the indentation of LdapRequest.java L103 ( in
> > > > the new file ). It appears, in the webrev, that the trailing `}` is
> > > > not lined up.
> > > > 
> > > > The indentation doesn’t look right here either.
> > > >    624             if (nparent) {
> > > >    625                 LdapRequest ldr = pendingRequests;
> > > >    626                 while (ldr != null) {
> > > >    627                     ldr.close();
> > > >    628                         ldr = ldr.next;
> > > >    629                     }
> > > >    630                 }
> > > >    631             }
> > > > 
> > > > -Chris
> > > > 
> > > 
>