Re: better atomics - v0.6

On 2014-09-23 13:50:28 +0300, Oskari Saarenmaa wrote:
> 23.09.2014, 00:01, Andres Freund kirjoitti:
> >I've finally managed to incorporate (all the?) feedback I got for
> >0.5. Imo the current version looks pretty good.
> >
> >Most notable changes:
> >* Lots of comment improvements
> >* code moved out of storage/ into port/
> >* separated the s_lock.h changes into its own commit
> >* merged i386/amd64 into one file
> >* fixed lots of the little details Amit noticed
> >* fixed lots of XXX/FIXMEs
> >* rebased to today's master
> >* tested various gcc/msvc versions
> >* extended the regression tests
> >* ...
> >
> >The patches:
> >0001: The actual atomics API
> 
> I tried building PG on Solaris 10/Sparc using GCC 4.9.0 (buildfarm animal
> dingo) with this patch but regression tests failed due to:
> 
> /export/home/os/postgresql/src/test/regress/regress.so: symbol
> pg_write_barrier_impl: referenced symbol not found
> 
> which turns out to be caused by a leftover PG_ prefix in ifdefs for
> HAVE_GCC__ATOMIC_INT64_CAS.  Removing the PG_ prefix fixed the build and
> regression tests.  Attached a patch to strip the invalid prefix.

Gah. Stupid last minute changes... Thanks for diagnosing. Will
integrate.

> >0002: Implement s_lock.h support ontop the atomics API. Existing
> >       implementations continue to be used unless
> >       FORCE_ATOMICS_BASED_SPINLOCKS is defined
> 
> Applied this and built PG with and without FORCE_ATOMICS_BASED_SPINLOCKS -
> both builds passed regression tests.

Cool.

> >0003-0005: Not proposed for review here. Just included because code
> >      actually using the atomics make testing them easier.
> 
> I'll look at these patches later.

Cool. Although I'm not proposing them to be integrated as-is...

Greetings,

Andres Freund