The math megamodule is a CORBA server that provides the following services:
	SETUP: Input is a string that contains the desired precision and 
format, outputs are the precision and format set by the service (the output 
is not really relevant). The service does not create any objects because 
the object MServer which offers these services is already created when the 
math megamodule server is started and registered at the ORB.
	INVOKE: Input is a string that contains the desired operation and 
two doubles containing the numbers on which the operation is to be 
performed. Output is again the desired operation (not really needed).
	EXTRACT: Input is a string (not used by the service), output is the 
result of the operation performed in the INVOKE service.
	TERMINATE: Input and output are strings that are not relevant. The 
object MServer is not deleted by this service, it gets deleted when the 
server terminates.
	
In contrast to the CHAIMS-syntax, neither the SETUP nor the INVOKE command 
return any handles. Therefore the math megamodule is not reentrant (no 
invocation handle), i.e. after the INVOKE command the result must first be 
read by the EXTRACT command before any further INVOKEs are called. 


We can distinguish between files on the client side, files on the server 
side and CORBA-specific files.
 	client side: client.cc
 	server side: server.cc, MM.cc, MM.h, MM_i.h, MM_i.cc 
 	CORBA-specific files: MM.idl, MM.hh, MMC.cc, MMS.cc
The file MM.idl contains the interface definition of the math megamodule in 
IDL (math megamodule is abreviated by MM).
The files MM.hh, MMC.cc, MMS.cc are generated by the IDL-compiler of CORBA, 
the compiler takes the file MM.idl as input. All the other files are coded 
by the programmer. The names of the two files MM_i.h, MM_i.cc are given by 
CORBA, the names for the files client.cc, server.cc, MM.cc, MM.h are chosen 
by the programmer. The file MM.hh has no direct relation to the files MM.h 
and MM.cc.
MM.h and MM.cc contain the effective math megamodule. MM_i.h and MM_i.cc 
contain a wrapper that wraps the effective math megamodule into the form 
required by the ORB.
Server.cc and client.cc each contain a main for starting the CORBA-server 
and CORBA-client.


Relationships between the files:
For diagrams explaining the relationships between files have a look at 
Overview_Mathmodule.ps.

The file MM.hh contains the abstract class MMBOAImpl (created by the 
IDL-compiler). This class declares the C++ mapping of all the services 
defined in the file MM.idl. The arguments are either native C++ types (e.g. 
char) or CORBA-types (e.g. CORBA::double).
The file MM_i.h defines the class MM_i, a subclass of MMBOAImpl. MM_i 
implements the abstract services of MMBOAImpl. Yet MM_i is only a wrapper. 
It creates an object of type MServer (defined in file MM.h) and dispatches 
all function calls to the functions of MServer. When dispatching, MM_i also 
performs the data-conversion from CORBA-types to native C++ types (e.g. 
from CORBA::double to double), because the class MServer is independent of 
CORBA and does not offer any CORBA-types in its interface. 
The file MM.h defines the class MServer. MServer provides the services of 
the math megamodule and is thus the core of the math megamodule. MServer 
could be used independant of the other files.
The file client.cc contains a main. The main uses the services provided by 
the math megamodule. The syntax is the one given by the class MMBOAImpl in 
file MM.hh. Before using the services, the main asks the ORB for the 
object-handle of the math megamodule (function MM::_bind, MM is also 
provided by MM.hh).
The file server.cc contains a main that creates the wrapper object MM_i and 
registers it at the ORB (function CORBA::Orbix.impl_is_ready("MM")).


Interactions:
For diagrams showing the interactions between the various objects, have a 
look at file Overview_Mathmodule.ps.