hc-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Sebb (JIRA)" <j...@apache.org>
Subject [jira] Commented: (HTTPCLIENT-841) potential memory leak when using ThreadSafeClientConnManager
Date Thu, 16 Apr 2009 13:37:15 GMT

    [ https://issues.apache.org/jira/browse/HTTPCLIENT-841?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12699701#action_12699701
] 

Sebb commented on HTTPCLIENT-841:
---------------------------------

The implementation is currently difficult to make thread-safe, so removing it would be good.

If redesigned, it would be good to remove/rework the enableConnectionGC() method, which can
only be called immediately after creating the pool.
The method creates additional instance objects (refQueue and refWorker); if these could be
optionally created at construction time they could be made final to improve thread-safety.
There would still need to be a way to start the RefQueueWorker thread after the AbstractConnPool
was created, but this could be done by the concrete subclass constructor (as is done now).

> potential memory leak when using ThreadSafeClientConnManager
> ------------------------------------------------------------
>
>                 Key: HTTPCLIENT-841
>                 URL: https://issues.apache.org/jira/browse/HTTPCLIENT-841
>             Project: HttpComponents HttpClient
>          Issue Type: Bug
>          Components: HttpClient
>    Affects Versions: 4.0 Beta 2
>         Environment: Leopard 10.5.6, Java 1.5.0_16, Jetty 6.1.7
>            Reporter: Ted Slusser
>             Fix For: 4.0 Beta 3
>
>
> When using ThreadSafeClientConnManager and developing with Jetty using auto-redeploy
feature eventually I run into a PermGen out of memory exception.  I investigated with YourKit
8.0.6 and found a class loader circular reference in RefQueueWorker.  Not really sure what
I was doing I made the refQueueHandler non-final and nulled it in the shutdown method of RedQueueWorker.
 I don't seem to have the problem any longer with circular class loader references.
> Here is a diff from 4.0-beta2
> --- httpclient/src/main/java/org/apache/http/impl/conn/tsccm/RefQueueWorker.jav(revision
763223)
> +++ httpclient/src/main/java/org/apache/http/impl/conn/tsccm/RefQueueWorker.jav(working
copy)
> @@ -50,7 +50,7 @@
>      protected final ReferenceQueue<?> refQueue;
>  
>      /** The handler for the references found. */
> -    protected final RefQueueHandler refHandler;
> +    protected RefQueueHandler refHandler;
>  
>  
>      /**
> @@ -112,6 +112,8 @@
>              this.workerThread = null; // indicate shutdown
>              wt.interrupt();
>          }
> +
> +        refHandler = null;
>      }
>  
>  

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@hc.apache.org
For additional commands, e-mail: dev-help@hc.apache.org


Mime
View raw message