Re: better atomics - v0.6

23.09.2014, 15:18, Andres Freund kirjoitti:
> On 2014-09-23 13:50:28 +0300, Oskari Saarenmaa wrote:
>> 23.09.2014, 00:01, Andres Freund kirjoitti:
>>> 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:
>
> Btw, if you could try sun studio it'd be great. I wrote the support for
> it blindly, and I'd be surprised if I got it right on the first try.

I just installed Solaris Studio 12.3 and tried compiling this:

"../../../../src/include/port/atomics/generic-sunpro.h", line 54: return
value type mismatch
"../../../../src/include/port/atomics/generic-sunpro.h", line 77: return
value type mismatch
"../../../../src/include/port/atomics/generic-sunpro.h", line 79:
#if-less #endif
"../../../../src/include/port/atomics/generic-sunpro.h", line 81:
#if-less #endif

atomic_add_64 and atomic_add_32 don't return anything (the
atomic_add_*_nv variants return the new value) and there were a few
extra #endifs.  Regression tests pass after applying the attached patch
which defines PG_HAS_ATOMIC_ADD_FETCH_U32.

There doesn't seem to be a fallback for defining pg_atomic_fetch_add
based on pg_atomic_add_fetch so pg_atomic_add_fetch now gets implemented
using pg_atomic_compare_exchange.

Also, it's not possible to compile PG with FORCE_ATOMICS_BASED_SPINLOCKS
with these patches:

"../../../../src/include/storage/s_lock.h", line 868: #error: PostgreSQL
does not have native spinlock support on this platform....

atomics/generic.h would implement atomic flags using operations exposed
by atomics/generic-sunpro.h, but atomics/fallback.h is included before
it and it defines functions for flag operations which s_lock.h doesn't
want to use.

/ Oskari