[ 
https://issues.apache.org/jira/browse/LUCENE-4025?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13265027#comment-13265027
 ] 

Hoss Man commented on LUCENE-4025:
----------------------------------

isn't this exactly why things like the ExecutorService and/or Future APIs 
exist?  let the caller decide if they want the methods they call to be executed 
in the current thread or as part of a thread pool and/or block until the logic 
is executed (with a possible time limit)
                
> ReferenceManager.maybeRefresh should allow the caller to block
> --------------------------------------------------------------
>
>                 Key: LUCENE-4025
>                 URL: https://issues.apache.org/jira/browse/LUCENE-4025
>             Project: Lucene - Java
>          Issue Type: Improvement
>          Components: core/search
>            Reporter: Shai Erera
>            Priority: Minor
>             Fix For: 4.0
>
>
> ReferenceManager.maybeRefresh() returns a boolean today, specifying whether 
> the maybeRefresh logic was executed by the caller or not. If it's false, it 
> means that another thread is currently refreshing and the call returns 
> immediately.
> I think that that's inconvenient to the caller. I.e., if you wanted to do 
> something like:
> {code}
> writer.commit();
> searcherManager.maybeRefresh();
> searcherManager.acquire();
> {code}
> It'd be better if you could guarantee that when the maybeRefresh() call 
> returned, the follow on acquire() will return a refreshed IndexSearcher. Even 
> if you omit the commit instruction, it'd be good if you can guarantee that.
> I don't quite see the benefit of having the caller thread not block if 
> there's another thread currently refreshing. In, I believe, most cases, you'd 
> anyway have just one thread calling maybeRefresh(). Even if not, the only 
> benefit of not blocking is if you have commit() followed by maybeRefresh() 
> logic done by some threads, while other threads acquire searchers - maybe 
> then you wouldn't care if another thread is currently doing the refresh?
> Actually, I tend to think that not blocking is buggy? I mean, what if two 
> threads do commit() + maybeRefresh(). The first thread finishes commit, 
> enters maybeRefresh(), acquires the lock and reopens the Reader. Then the 
> second thread does its commit(), enters maybeRefresh, fails to obtain the 
> lock and exits. Its changes won't be exposed by SM until the next 
> maybeRefresh() is called.
> So it looks to me like current logic may be buggy in that sense?

--
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

        

---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org
For additional commands, e-mail: dev-h...@lucene.apache.org

Reply via email to