Subject: SDL-News: non-blocking external DB access from within a proce ss
From: Elie Cohen (cohen#verilogusa.com )
Date: Wed Aug 18 1999 - 05:27:44 GMT
The originator of this message is responsible for its content.
-----From cohen#verilogusa.com (Elie Cohen) to sdlnews -----
Dear SDL Community,
I have been waiting for an official representative of Telelogic to
give their opinion/solution on this subject and it has not come yet.
As a user of ObjectGEODE and a consultant/trainer at VERILOG, I think
you all deserved some help from you favorite vendor. Maybe they do not
deserve to be your favorite vendor.
Not only all you're asking for is doable with ObjectGEODE, it is easy,
and there are at least two ways of achieving the results.
ObjectGEODE supports UNIX not with one, but two TIGHTLY coupled
libraries. The UNIX library and the POSIX library. Both libraries
target Solaris, HP-UX, LINUX, and various other flavors of UNIX.
In both cases, UNIX and POSIX, the user can choose the MAPPING he/she
With the UNIX library, you can map the SDL system or an SDL block to a
UNIX box (possibly multiprocessor), you can map an SDL block, SDL
process or SDL process instance to a UNIX process.
If you choose the POSIX library, you can map the SDL system or an SDL
block to a POSIX box (like in UNIX, possibly multiprocessor). Unlike
UNIX, though, you can map them (SDL process or block) to a POSIX
executable (POSIX process). In addition, you can choose to map an SDL
block, SDL process or SDL process instance to a POSIX thread inside
the POSIX executable.
In all cases, an SDL process instance gets an execution thread of its
own, as specified by the SDL semantics.
But what if you decide to map the enclosing SDL block to a POSIX
thread (or a UNIX process), the SDL process instance is not "visible"
to the POSIX/UNIX scheduler anymore? True, and that is the reason why
ObjectGEODE takes over and does its own scheduling if necessary,
INSIDE the UNIX process or POSIX thread.
I sure hope this makes clear that SDL does support "non blocking DB
access", even if not all vendors/code generation tools are made equal
in their support of SDL semantics.
A last point - this post is already way too long - ObjectGEODE
provides you with inter-process and inter-processor communication (you
get TCP/IP or UDP/IP with the libraries), and unless your very goal is
to model some other type of communication protocol, there is no work
necessary on the user's part.
As a strong supporter of SDL, I sure start to feel threatened by
people mentioning ObjecTime in this mailing list. Don't you?
---- Elie Cohen - Engineering Manager Phone: 760 533 2186 Fax: 760 944 3842
VERILOG, Inc. 2186 Corte Acebo Carlsbad, CA 92009
-----End text from cohen#verilogusa.com (Elie Cohen) to sdlnews ----- Join http://www.sdl-forum.org/Society/members.htm for extra SDL Forum Society benefits For help, email "majordomo#sdl-forum.org" with the body of your email as: help or (iff this does not answer your question) email: owner-sdlnews#sdl-forum.org
This archive was generated by hypermail 2a23 : Sun Jun 16 2013 - 10:41:41 GMT