[OFBiz] Dev - RE: [OFBiz] SVN: r4785 - trunk/framework/jotm/lib

[David E. Jones]

Ryan,

Which object in particular are you referring to here that has the 
transactionTimeout variable? Are you referring to the UserTransaction 
object?

There isn't much we can do about that, it's part of the JTA spec. There 
probably isn't much they can do inside the implementation of that 
interface either... Another great  artifact of OO design gone awry...

One possible solution is in our own TransactionUtil.begin method to 
synchronize the whole method. We could synchronize just the are around 
those 2 calls (which are right next to eachother), but as I understand 
it that is not entirely safe, best if the whole method is synchronized.

Looking at this code, there is another problem.... It sets the 
transaction timeout, but never sets it back to the default... I added a 
fix for that too.

That is in SVN now.

-David


On Apr 8, 2005, at 11:19 AM, Ryan Warnick wrote:

> I just had a look at the fix in JOTM and it still looks like there is 
> an
> issue.  Even though some of the problems were resolved, there is still 
> a
> race condition.  Here is my thinking:
>
> The core issue is that there is only ONE Current object and it has only
> ONE member variable called transactionTimeout.  Ofbiz uses the begin()
> method which sets the transaction timeout value for the new transaction
> to the value of transactionTimeout.  So, if one thread calls
> setTransactionTimeout and sets the timeout to 60 seconds and before 
> that
> same thread can call begin another thread calls setTransactionTimeout
> and sets it 30 seconds, then the original thread's transaction timeout
> will be 30 seconds.  The transactionTimeout member variable is being
> shared by all threads and it seems like only way to prevent the race
> condition is to make calls to setTransactionTimeout and begin atomic.
> Of course, there are some better ways to address this issue, such as
> having a begin() method that accepts the timeout as an input and just
> uses it locally for the transaction.
>
> Ryan
>
> -----Original Message-----
> From: svn-bounces at lists.ofbiz.org [mailto:svn-bounces at lists.ofbiz.org]
> On Behalf Of jaz at svn.ofbiz.org
> Sent: Thursday, April 07, 2005 3:07 PM
> To: svn at lists.ofbiz.org
> Subject: [OFBiz] SVN: r4785 - trunk/framework/jotm/lib
>
>
> Author: jaz
> Date: 2005-04-07 16:06:19 -0500 (Thu, 07 Apr 2005)
> New Revision: 4785
>
> Modified:
>    trunk/framework/jotm/lib/carol.jar
>    trunk/framework/jotm/lib/jotm.jar
>    trunk/framework/jotm/lib/jotm_iiop_stubs.jar
>    trunk/framework/jotm/lib/jotm_jrmp_stubs.jar
> Log:
> updated to JOTM 'HEAD' (pre 2.0.9) which fixed setTransactionTimeout()
> bug
>
>
> Modified: trunk/framework/jotm/lib/carol.jar
> ===================================================================
> (Binary files differ)
>
> Modified: trunk/framework/jotm/lib/jotm.jar
> ===================================================================
> (Binary files differ)
>
> Modified: trunk/framework/jotm/lib/jotm_iiop_stubs.jar
> ===================================================================
> (Binary files differ)
>
> Modified: trunk/framework/jotm/lib/jotm_jrmp_stubs.jar
> ===================================================================
> (Binary files differ)
>
>
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