Re: [COMMITTERS] pgsql: Make it easy to detach completely from shared memory.

On 18 March 2014 13:51, Tom Lane  wrote:
> Robert Haas  writes:
>> On Tue, Mar 18, 2014 at 8:41 AM, Simon Riggs  wrote:
>>> Perhaps we should consider a parameter for PGSharedMemoryDetach() ?
>
>> Yeah, maybe.  It seems like a possible modularity violation, because
>> the PGSharedMemory... stuff has heretofore not needed to know anything
>> about DSM, and apart from this one function, it still wouldn't.
>
> That was exactly the reason we rejected that design upthread.
> PGSharedMemoryDetach is specific to the main shmem segment, and in fact
> has multiple OS-dependent implementations.
>
> You could make an argument for inventing some new wrapper function that
> calls both PGSharedMemoryDetach and dsm_detach_all, but I don't believe
> that the existing flavors of that function should know about DSM.

I'm not bothered which we choose, as long as its well documented to
ensure people that use those calls don't detach from just one when
they really would wish to detach from both.

-- Simon Riggs                   http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training & Services