From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-0.9 required=5.0 tests=BAYES_00,FORGED_GMAIL_RCVD, FREEMAIL_FROM autolearn=no autolearn_force=no version=3.4.4 X-Google-Thread: a07f3367d7,a52626a9019b830 X-Google-Attributes: gida07f3367d7,public,usenet X-Google-NewGroupId: yes X-Google-Language: ENGLISH,UTF8 Received: by 10.224.220.12 with SMTP id hw12mr3220709qab.8.1347396627638; Tue, 11 Sep 2012 13:50:27 -0700 (PDT) Received: by 10.52.33.34 with SMTP id o2mr3361826vdi.12.1347396627542; Tue, 11 Sep 2012 13:50:27 -0700 (PDT) Path: da15ni3445qab.0!nntp.google.com!v8no244889qap.0!postnews.google.com!glegroupsg2000goo.googlegroups.com!not-for-mail Newsgroups: comp.lang.ada Date: Tue, 11 Sep 2012 13:50:27 -0700 (PDT) In-Reply-To: Complaints-To: groups-abuse@google.com Injection-Info: glegroupsg2000goo.googlegroups.com; posting-host=46.171.80.166; posting-account=bMuEOQoAAACUUr_ghL3RBIi5neBZ5w_S NNTP-Posting-Host: 46.171.80.166 References: <3b3a796d-50e0-4304-9f8d-295fb2ed0e82@googlegroups.com> <1hrmrgblczf2p.x7ar7hqalypi.dlg@40tude.net> <6b311ca1-9630-4874-b068-2b6b08c1ffa9@googlegroups.com> User-Agent: G2/1.0 MIME-Version: 1.0 Message-ID: Subject: Re: Help writing first daemon From: Maciej Sobczak Cc: mailbox@dmitry-kazakov.de Injection-Date: Tue, 11 Sep 2012 20:50:27 +0000 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Date: 2012-09-11T13:50:27-07:00 List-Id: W dniu wtorek, 11 wrze=C5=9Bnia 2012 17:13:06 UTC+2 u=C5=BCytkownik Dmitry = A. Kazakov napisa=C5=82: > >> But, if you consider running the middleware as a system service (daemo= n), > >> the main reason for that would be the architecture of shared memory. > >=20 > > No, there is no connection between these two concepts. >=20 > The concepts are single vs. multiple instances middleware. No. System services and shared memory are low-level building blocks that ca= n be used to construct software that actually does something useful. Whethe= r that software exists in a single vs. multiple instances is a matter of te= rminology that is defined on a much higher level and has nothing to do with= how many processes there are or how they communicate. For example, a well known database server is said to exist in a single inst= ance, while being physically composed of many processes (presumably system = services) communicating with each other. These concepts exist on different = levels. > > System services are created so they can be started and run unattended e= ven > > after system restarts. A free-standing web server is a possible example= here. >=20 > And there is no reason for a web server to be a system service. I will repeat, then: *unattended*. This usually means that the software can= start automatically and does not rely on any interactions via terminal or = GUI. > I see web > server as an application. It's possible to use it this way. It is just not how everybody does it. (Note: we didn't define "application" here and I'm not willing to spend my = time on terminology wars.) > A dedicated system service and pipes are in the same league. Pipes > themselves is a service. Pipes are a system-level service, just like dynamic memory. You can use the= m to build other, high-level services like web servers or database servers,= but web server is certainly not in this league. But I promised not to jump into terminology wars, so I quit. --=20 Maciej Sobczak * http://www.msobczak.com * http://www.inspirel.com