home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
OS/2 Shareware BBS: 10 Tools
/
10-Tools.zip
/
opendc12.zip
/
SG244883.ZIP
/
2_7.4
< prev
next >
Wrap
Text File
|
2001-01-27
|
7KB
|
162 lines
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN">
<HTML>
<HEAD>
<base href="http://publib.boulder.ibm.com:80/cgi-bin/bookmgr/BOOKS/EZ30OZ00/2.7.4">
<title>
2.7.4 "OS/2 WARP and OpenDoc"
via IBM BookManager BookServer
</title>
</head>
<body background="/bookmgr/backdrop.gif">
<banner><br>
<a href="../../library"><img src="/bookmgr/libicon2.gif" border=0 alt="[Library]"></a>
<a href="CONTENTS#2.7.4"><img src="/bookmgr/contents.gif" border=0 alt="[Contents]"></a>
<img src="/bookmgr/drevs.gif" border=0 alt="[Revisions]">
<a href="2.7.3"><img src="/bookmgr/prev.gif" border=0 alt="[Prev Topic]"></a>
<a href="2.7.5"><img src="/bookmgr/next.gif" border=0 alt="[Next Topic]"></a>
<a href="../../search?book=EZ30OZ00"><img src="/bookmgr/search.gif" border=0 alt="[Search]" ></a>
<img src="/bookmgr/dslist.gif" border=0 alt="[Search Results]">
<img src="/bookmgr/dsprev.gif" border=0 alt="[Prev Topic Match]">
<img src="/bookmgr/dsnext.gif" border=0 alt="[Next Topic Match]">
<img src="/bookmgr/dnotes.gif" border=0 alt="[Notes]">
<img src="/bookmgr/dlnotes.gif" border=0 alt="[List Notes]">
<a href="../../print?book=EZ30OZ00"><img src="/bookmgr/print.gif" border=0 alt="[Print]"></a>
<a href="../../download/EZ30OZ00.boo"><img src="/bookmgr/download.gif" border=0 alt="[Download]" ></a>
<a href="../../help/book"><img src="/bookmgr/help.gif" border=0 alt="[Help]"></a>
<hr>
<a name="HDR4610DDI"><H3> 2.7.4 Distributed SOM</H3></a>
</banner>
<pre width="80">
<p>
SOM technology insulates the object client from the object's
implementation. The power of distributed SOM lies in the fact that
distributed SOM insulates the object client from the object's location.
<p>
Distributed SOM allows application programs to access objects across
address spaces. That is, application programs can access objects in other
processes, even on different machines. Both the location and
implementation of an object are hidden from a client, and the client
accesses the object (through method calls) in the same manner regardless
of its location. Distributed SOM can be characterized in the following
two ways:
<p>
<p>
░ As an extension to the system object model, that allows a program to
invoke methods on SOM objects in other processes.
<p>
░ As an object request broker (ORB), that is, a standardized transport
for distributed object interaction. In this respect, distributed SOM
complies with the Common Object Request Broker Architecture (CORBA)
specification.
<p>
<p>
<a name="FIG4610D07"><hr>
</a>
<p>
<p>
<a href="picture-40?mode=zoom"><img src="/bookmgr/pictures/EZ30OZ00.P40.GIF" alt="PICTURE 40"></a>
<p>
Process Communication (IPC)
<p>
<hr>
Figure 40. Local DSOM Object Requests to Other Processes Using Inter
<p>
Some of Distributed SOM's more important features include the following:
<p>
░ Uses the standard SOM Compiler, Interface Repository, language
bindings, and class libraries. Distributed SOM provides a growth path
for non-distributed SOM applications.
<p>
░ Allows an application program to access a mix of local and remote
objects. The fact that an object is remote is transparent to the
program.
<p>
░ Supports both interprocess communication in the same system, as shown
in <a href="#FIG4610D07">Figure 40</a>, and remote transport across systems, as shown in
<a href="#FIG4610D08">Figure 41</a>.
<p>
░ It is protocol independent, supporting TCP/IP, Netbios, IPX and can be
extended for other protocols.
<p>
░ It is platform independent supporting OS/2, AIX, Windows, Macintosh,
HP/UX, OS/400, and MVS. Other platforms are under considerations.
<p>
<p>
The local DSOM support on one machine is delivered together with the SOM
2.1 run time with OS/2 Warp Version 3.
<p>
<a name="FIG4610D08"><hr>
</a>
<p>
<p>
<a href="picture-41?mode=zoom"><img src="/bookmgr/pictures/EZ30OZ00.P41.GIF" alt="PICTURE 41"></a>
<p>
<p>
<hr>
Figure 41. Remote Object Requests to Other Machines
<p>
The way DSOM is hiding the complexity of client/server programs to its
clients is done by a clever proxy technology. DSOM is creating, during
run time, an instance of a proxy class within in the address space of the
client process. This proxy implements the interface of the addressee class
on the remote machine. But the interface is overridden in a way that all
requests are transparently forwarded to the target object.
<p>
<a name="FIG4610D35"><hr>
</a>
<p>
<p>
<a href="picture-42?mode=zoom"><img src="/bookmgr/pictures/EZ30OZ00.P42.GIF" alt="PICTURE 42"></a>
<p>
<p>
<hr>
Figure 42. DSOM Object Communication
<p>
Using DSOM, the same interface of an object can be used without
modifications, running locally in the same address space as other client
objects or on a remote server.
<p>
No client/server code has to be included. CORBA technology is not only
great for objects being distributed somewhere in the network, it is also a
great integration technology, wrapping and encapsulating legacy
applications as shown in <a href="#FIG4610D10">Figure 43</a>. The interfaces of legacy applications
can be described in IDL and then used and integrated by SOM/DSOM from
other applications.
<p>
<a name="FIG4610D10"><hr>
</a>
<p>
<p>
<a href="picture-43?mode=zoom"><img src="/bookmgr/pictures/EZ30OZ00.P43.GIF" alt="PICTURE 43"></a>
<p>
<p>
<hr>
Figure 43. Integration of Legacy Applications Using DSOM
<p>
DSOM can be used for OpenDoc to have flexible access to distributed
components as shown in <a href="#FIG4610D40">Figure 44</a>.
<p>
<p>
<a name="FIG4610D40"><hr>
</a>
<p>
<p>
<a href="picture-44?mode=zoom"><img src="/bookmgr/pictures/EZ30OZ00.P44.GIF" alt="PICTURE 44"></a>
<p>
<p>
<hr>
Figure 44. DSOM and OpenDoc
</pre>
</pre>
<hr>
<br><a href="2.7.3"><img src="/bookmgr/prev.gif" border=0 alt="[Prev Topic]"></a>
<a href="2.7.5"><img src="/bookmgr/next.gif" border=0 alt="[Next Topic]"></a>
<cite> ⌐ Copyright IBM Corp. 1996</cite>
<HR><p><h6><a href="/cgi-bin/bookmgr/library">IBM BookManager« BookServer</a> Copyright 1989, 1999<a href="http://www.ibm.com/"> IBM</a> Corporation. All rights reserved.</h6><p>
</BODY></HTML>