1	Preface


NCSA DTM	1



National Center for Supercomputing Applications



October 1992


October 1992



1	Preface


NCSA DTM	1



National Center for Supercomputing Applications



October 1992


NCSA DTM	1


October 1992



1	Part I:  The Basic Concepts


NCSA DTM	1



National Center for Supercomputing Applications



October 1992


                                                              


February 1992


                                                                

NCSA DTM	Preface



Introduction		1
Outline		1
Version		1
Font Conventions		1




Introduction
The Data Transfer Mechanism (DTM) is a message passing facility.  It 
is designed to simplify the task of interprocess communication and to 
facilitate the creation of sophisticated distributed applications in a 
heterogeneous environment.  To accomplish this, DTM provides a 
method of interconnecting applications at run-time and provides 
reliable message passing complete with synchronization and 
transparent data conversion.  DTM has been optimized for large 
messages (100 KBytes and up), but is efficient for smaller messages as 
well.

The purpose of this manual is to provide the applications programmer 
and research scientist with a basic understanding of how to write or 
modify code to support the use of DTM.  No prior knowledge of DTM is 
required, nor knowledge of the underlying concepts behind distributed 
computing.  However, knowledge of the programming language "C" is 
necessary if the reader desires to use the many sample programs found 
within.  All sample code is written in ANSI C.

Outline
This tutorial has two parts: a description of the DTM protocol and a 
tutorial on how to use the DTM and message class library.  The first 
section presents the major ideas behind DTM and how it works, with 
suggestions on how DTM can be used to enhance applications.  The 
tutorial presents a step by step look at how to add DTM to an 
application, from creating a port to sending/receiving a message to 
checking ports for communication capability.

Hopefully plenty of source code examples are provided in this 
document.  Each example comes from a working program which is 
provided with the electronic distribution of the DTM source and 
documentation.  For a copy of these examples, or to find out where 
these examples exist on NCSA machines, send mail to 
"softdev@ncsa.uiuc.edu".  To report bugs in either the example code or 
in the DTM library itself, send mail to "bugs@ncsa.uiuc.edu".

Version
This tutorial was written for DTM version 2.3.  To determine which  
version of DTM you are currently using, check the README file 
included in the DTM tar file or make and run the "version" program 
supplied with the examples.

Font Conventions
Italics are used for:
¥	file names, program names and options for user commands
¥	new terms when they are defined

Courier Font is used for:
¥	source code, constants, or anything that needs to be typed verbatim
¥	structure types, structure members, functions and macros

Italic Courier Font  is used for:
¥	arguments to functions, since they are arbitrary

Boldface is used for:
¥	chapter and section headings
¥	titles of examples 


