Cool. Oliver
2005/11/22, Cservenak Tamas <[EMAIL PROTECTED]>: > Hi, > > thank you for response. Jorg already convinced me to use some external Id > generator, and not the handy built in (which was a handy solution for fast > jump-in). > > My "patch" for generatedTxId will be simply moved to my code and it will do > the trick, as it solves my problem. > > Thank you for help, > Tamas > > > Oliver Zeigermann wrote: > To me it seems generatedUniqueTxId does exactly as advertised in > Javadocs. Don't you agree? > > You simply need something different as it seems. Unique Id generators > - that's what you need - are easy to find, even in the Jakarta Commons > Project :) > > Oliver > > 2005/11/22, Cservenak Tamas <[EMAIL PROTECTED]>: > > > Yes, youre right. > > Anyway, in my case it would be more appropriate to generate Tx ID's by > myself to avoid generatedUniqueTxId() problem. As first step i will probably > copy this patched method into my code and use it instead of calling > frm.generated.... > > Thanks for help. And sorry for bothering, this should go to the users > maillist, not dev, right? > > ~t~ > > > > Joerg Heinicke wrote: > Cservenak Tamas <cservenak <at> is-micro.hu> writes: > > > > The generatedUniqueTxId() method in FileResourceManager uses > System.currentTimeMillis() to generate txId's. > > On my system it causes duplicate txId generation and FRM failure. I have > 4 threads accessing one FRM instance. > > This simple patch adds "salt" to it, with a little overhead to solve > this problem. > > Unfortunately this does not help much, it only solves your problem "under > heavy > load". But if there is already another txId equal to this one (e.g. > generated > externally) FRM will again fail. It can only work if inside the synchronized > block the generated txId is "preserved", e.g. by putting a final static > object > PRESERVED into the map and testing for it in the startTransaction(Object) > method. > > This will solve almost all problems except one: > 1. Thread 1: generateUniqueTxId() > 2. Thread 2: startTransaction(txId) with an externally generated txId - > coincidentally equal to the above generated one > 3. Thread 1: startTransaction(txId) with the generated txId > > But is again a magnitude more unlikely. > > Jörg > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: > [EMAIL PROTECTED] > For additional commands, e-mail: > [EMAIL PROTECTED] > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: > [EMAIL PROTECTED] > For additional commands, e-mail: > [EMAIL PROTECTED] > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: > [EMAIL PROTECTED] > For additional commands, e-mail: > [EMAIL PROTECTED] > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: > [EMAIL PROTECTED] > For additional commands, e-mail: > [EMAIL PROTECTED] > > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
