Re: [Gems-users] TM conflict case doubt

[holey003@xxxxxxx]

I went through the code but little confusion is still there. How it is 
decided to restart all the transactions or retry for detected conflict?
On Sep 12 2009, ruzhu kao wrote:

> I/O is one of the darknesses in TM.  You may read codes in ruby/log_tm
>
> 2009/9/13  <holey003@xxxxxxx>:
> > Hi,
> >
> > I have some doubt regarding TM operation on conflict. Suppose executing
> > code looks like this:
> >
> > BEGIN_TRANSACTION(x)
> >   io_operation();     //1
> >   a = b + c;          //2
> >   c++;                //3
> >   b = a + c;          //4
> > COMMIT_TRANSACTION(x)
> >
> > Suppose conflict is detected for updating 'c'. Then corresponding core
> > retries same transaction or again starts from line 1? What I understood 
> > is,
> > if logically later thread detects conflict, then it should restart the
> > whole thread as previous thread must update 'c' first and then should be
> > read by current thread. If so, where is this functionality implemented? 
> > In
> > transaction.c file?
> >
> > Isn't it possible that logically later thread gets hold of 'c' before the
> > earlier thread because earlier thread is busy in i/o operation? Then the
> > earlier thread will detect conflict?
> >
> > I am using benchmarks in microbenchmarks/transactional.
> >
> > Thanks,
> > Anup
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