topic Re: LockService Issue in Alfresco Archive

LockService Issue

joaotpd — Fri, 23 Mar 2012 13:00:21 GMT

Hi all!I'm using alfresco 3.4.3 in linux…When a user creates a document that is numbered. To avoid duplication in numbering I have a counter and I'm using lockService as followsquite simply, I think!)import org.alfresco.service.cmr.lock.LockService;import org.alfresco.service.cmr.lock.LockType;//…

Re: LockService Issue

mrogers — Fri, 23 Mar 2012 13:16:37 GMT

Yes there's a big problem with the way that you are handling exceptions and transactions.

The lock method is not behaving as you would expects since at the point the lock method returns the transaction has not yet completed.

Really what the lock method is saying is that I'd like to take a lock if at all possible. When it comes back successfully its simply saying that no-one else has the lock at that point. The entire transaction could subsequently fail. But then it will be automatically retry and succeed or fail on the retry.

Re: LockService Issue

joaotpd — Fri, 23 Mar 2012 18:56:34 GMT

Hi mrogers,

Thanks for the reply…

Are you suggesting retrying transactions to do the content lock?… I'm doing the lock when the content is submited… is that the right way? …

João

Re: LockService Issue

joaotpd — Thu, 29 Mar 2012 15:25:25 GMT

Hi again,

I've updated the code this way (with retrying transactions in mind):

if (counterRef != null)
{
   // lock counter
   lockService.lock(counterRef, LockType.WRITE_LOCK);
           
   // get the value
   Integer count = (Integer)nodeService.getProperty(counterRef, CustomContentModel.PROP_INPUTNUMBER);
   count++;
         
   // saves the value
   nodeService.setProperty(counterRef, CustomContentModel.PROP_INPUTNUMBER, count);
         
   // unlock counter
   lockService.unlock(counterRef);
           
   return count;
}‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

much more simple, I think! …

Util now I've no duplicated references… Is this a better way to use lock service?

Can someone please comment… …

Thanks in advance,

João