Re: [HACKERS] walsender & parallelism

On 2017-04-24 04:27:58 +0200, Petr Jelinek wrote:
> On 24/04/17 01:43, Andres Freund wrote:
> > 
> >> BTW while looking at the code, I don't understand why we call
> >> latch_sigusr1_handler after calling SetLatch(MyLatch), shouldn't just
> >> the SetLatch be enough (they both end up calling sendSelfPipeByte()
> >> eventually)?
> > 
> > Historic raisins - there didn't use to be a SetLatch in
> > procsignal_sigusr1_handler. That changed when I whacked around catchup &
> > notify to be based on latches ([1] and following).
> > 
> > [1] https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=59f71a0d0b56b2df48db4bf1738aece5551f7a47
> > 
> 
> Okay, but why call both SetLatch and latch_sigusr1_handler? What does
> that buy us?

Nothing.  It's how the code evolved, we can change that.