Re: single task postgresql

On Wed, 27 Feb 2002, mlw wrote:

> Greg Copeland wrote:
> >
> > Windows does not really have shared memory support. This has been a
> > beef with the Win32 API for a long time now. Because it has been a long
> > time complaint, it was finally added in Win2000 and later. Likewise,
> > I'd like to point out that thinks like sims, shared memory, pipes, etc,
> > and other entities commonly used for concurrent programming strategies
> > are slower in XP. So, because shared memory really isn't well
> > supported, they elected to have what is, in essense, memory mapped
> > files. Multiple processes then map the same file and read/write to it
> > as needed, more or less as you would shared memory. Unless you plan on
> > only targetting on Win 2000 and XP, it sounds like a waste of time.
>
> This is not really true. Under DOS windows, i.e. 95,98, etc. Shared memory can
> be done in 16 bit land with a touch of assembly and a DLL. Allocate, with
> globalalloc, a shared memory segment. The base selector is a valid 32 bit
> selector, and the memory is mapped in the above 2G space shared and mapped to
> all 32bit processes.
>
> Under NT through 2K, yes using a memory mapped files is the way to do it, but
> you do not actually need to create a file, you can use (HANDLE)0xFFFFFFFF,
> which is the NT equivilent of the system memory file. The handle returned is a
> system global object which can be shared across processes.
>

Mark,

do you consider to work on this issue ?

>
> >
>

Regards,
Oleg
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Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
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