[jira] Updated: (TAPESTRY-1571) CheckForUpdatesFilter can cause deadlock

["Ben Sommerville (JIRA)" <de...@tapestry.apache.org>]

     [ https://issues.apache.org/jira/browse/TAPESTRY-1571?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Ben Sommerville updated TAPESTRY-1571:
--------------------------------------

    Attachment: TAP-1571.patch

Patch that:
 - adds a tryWithWrite method to ConcurrentBarrier
 - changes CheckForUpdatesFilter to use tryWithWrite instead of withWrite
 - add configution parameter for the try update timeout.

> CheckForUpdatesFilter can cause deadlock
> ----------------------------------------
>
>                 Key: TAPESTRY-1571
>                 URL: https://issues.apache.org/jira/browse/TAPESTRY-1571
>             Project: Tapestry
>          Issue Type: Bug
>          Components: tapestry-core
>    Affects Versions: 5.0.5
>            Reporter: Ben Sommerville
>         Attachments: TAP-1571.patch
>
>
> CheckForUpdatesFilter will cause a deadlock in the following circumstances.
> 1) Initial request is received and processing starts  (CheckForUpdatesFilter read lock obtained)
> 2) Request processing triggers another http request to the same application
> 3) Nested request is received
> 4) CheckForUpdatesFilter determines it is time to check for file updates
> 5) CheckForUpdatesFilter tries to obtain write lock
> 6) Deadlock: Nested request is blocked waiting for read lock held by parent request to be released.
> This is an unusual situation, generally I wouldn't try to to access a page via http whilst trying to process another request.  However I ran across this problem whilst using a third party library (JasperReports) that referenced resources via http links.  
> Although uncommon, I believe Tapestry should be able to handle this without deadlocking

-- 
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@tapestry.apache.org
For additional commands, e-mail: dev-help@tapestry.apache.org