Re: Structure of the multitasking server

[Maciej Sobczak <see.my.homepage@gmail.com>]

On 22 Wrz, 04:32, a...@anon.org (anon) wrote:

>   Why use "GNAT.Sockets.Check_Selection"?

> [...] basically it has to do with limited
> system resources.

Of course, but as I've said, the intended (fixed) number of pipelines
is relatively small and the system resources do not seem to be any
limitation.

> Note: TCP/IP "Accept" can only monitor one connection port while the
> TCP/IP "Select" allows monitoring up to 32 at one time in one routine.
> which makes the TCP/IP "Select" a better utilization of system resources.

I don't understand this assertion. You cannot *replace* accept with
select, they serve completely different purposes, so you cannot state
that one is better than another.

> Why only 27 servers per TCP/IP "Select" routine  Well, the designers created
> the TCP/IP "Select" to use 3 32-bit word to detect or flag

This is an implementation detail that does not seem to be true any
longer. As I've already explained, on my system the default limit for
select(2) is 1024 descriptors and with a simple compiler option can be
actually unlimited.

The limit of 32 seems to be very impractical today. It is not uncommon
to have hundreds of clients connected at the same time to a single
server. They can be all handled without any partitioning.

> Plus, some system may have 1024 file descriptors, but the OS normally
> limit the number of assigned/open file descriptors to 32 or less.

Again, this is not true on any of the systems that I have access to.

--
Maciej Sobczak * www.msobczak.com * www.inspirel.com

Database Access Library for Ada: www.inspirel.com/soci-ada