[jboss-jira] [JBoss JIRA] Commented: (EJBTHREE-1501) Operations on cacheMap are not thread safe

[Brian Stansberry (JIRA)]

    [ https://jira.jboss.org/jira/browse/EJBTHREE-1501?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12430826#action_12430826 ] 

Brian Stansberry commented on EJBTHREE-1501:
--------------------------------------------

That's going to hold the map lock through a potentially long-running call to container.destroy(ctx) which calls any @PreDestroy.

Before incurring that cost, what's the scenario  where this is a problem, and can that scenario be solved another way, e.g. with a finer-grained lock, e.g. on the context rather than the cacheMap?


> Operations on cacheMap are not thread safe
> ------------------------------------------
>
>                 Key: EJBTHREE-1501
>                 URL: https://jira.jboss.org/jira/browse/EJBTHREE-1501
>             Project: EJB 3.0
>          Issue Type: Sub-task
>    Affects Versions: AS 4.2.3.GA, 1.0.0-Beta3
>            Reporter: Galder Zamarreno
>            Assignee: Galder Zamarreno
>
> Finally, code like this is not thread safe:
>       synchronized (cacheMap)
>       {
>          ctx = (StatefulBeanContext) cacheMap.get(key);
>       }
>       if(ctx == null)
>          throw new NoSuchEJBException("Could not find Stateful bean: " + key);
>       if (!ctx.isRemoved())
>          container.destroy(ctx);
>       
>       ++removeCount;
>       
>       if (ctx.getCanRemoveFromCache())
>       {
>          synchronized (cacheMap)
>          {
>             cacheMap.remove(key);
>          }
>       }
> This is essentiall a removeIfPresent type of operation on cacheMap and hence 
> get() and remove() operation, as they depend on each other, should be in a 
> single synchronized statement. Example:
>       synchronized (cacheMap)
>       {
>          ctx = (StatefulBeanContext) cacheMap.get(key);
>          if(ctx == null)
>             throw new NoSuchEJBException("Could not find Stateful bean: " + key);
>          if (!ctx.isRemoved())
>             container.destroy(ctx);
>       
>          ++removeCount;
>       
>          if (ctx.getCanRemoveFromCache())
>          {
>             cacheMap.remove(key);
>          }
>      }

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