Re: Posix Shared Mem patch

Magnus Hagander <magnus(at)hagander(dot)net> writes:
> On Wed, Jun 27, 2012 at 3:50 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> I wonder whether this design can be adapted to Windows? IIRC we do
>> not have a bulletproof data directory lock scheme for Windows.
>> It seems like this makes few enough demands on the lock mechanism
>> that there ought to be suitable primitives available there too.

> I assume you're saying we need to make changes in the internal API,
> right? Because we alreayd have a windows native implementation of
> shared memory that AFAIK works,

Right, but does it provide honest protection against starting two
postmasters in the same data directory? Or more to the point,
does it prevent starting a new postmaster when the old postmaster
crashed but there are still orphaned backends making changes?
AFAIR we basically punted on those problems for the Windows port,
for lack of an equivalent to nattch.

regards, tom lane