NS2: Binding C++ and OTcl variables

NS2: Binding Variables by Teerawat Issariyakul http://www.ns2ultimate.com July 2010 http://www.ns2ultimate.com

Outline
Introduction
Motivation
What we would like to do
Let’s bind the variables
See if it works
http://www.ns2ultimate.com

Introduction
This is a series on how NS2 binds C++ and OTcl together. This is the second topic of the series:
1. Why Two Languages?
2. Binding C++ and OTcl classes
3. Variable binding
4. OTcl command: Invoking C++ statements from the OTcl domain
5. Eval and result: Invoking OTcl statements from the C++ domain
6. Object binding and object construction process.

Motivation
C++: Internal mechanism
OTcl: Configuration
Modify C++ class variable from OTcl domain and vice versa.
http://www.ns2ultimate.com MyObject MyOTclObject ocount_ count_

What we would like to do http://www.ns2ultimate.com
C++:
class = MyObject
variable = count_
OTcl:
class = MyOTclObject
variable = ocount_
Bind C++ and OTcl
MyObject MyOTclObject binding class name binding variable ocount_ count_

Let’s Bind the Variable
Binding class name [see here and here ]
http://www.ns2ultimate.com static class MyObjectClass : public TclClass { public: MyObjectClass() : TclClass("MyOTclObject") {} TclObject* create(int, const char*const*) { return (new MyObject()); } } class_my_object;

Binding Syntax
Put the following command in the C++ constructor:
otcl_var_name = the name of OTcl variable
c_var_name = the name of C++ variable
Example:
http://www.ns2ultimate.com bind(“<otcl_var_name>”,<c_var_name>); MyObject::MyObject() { bind("ocount_",&count_); count_ = 10; }

Summary of Key Steps
Create file otcl.cc and otcl.h with the details explained earlier
Modify Makefile —including otcl.o into the compilation list [see detail here]
run “ make ” from the command prompt
Create file otcl.tcl for testing
4.1 In the C++ constructor: set count_ to be 10
4.2 Create an OTcl object
4.3 Show the value of count_ on the screen
4.4 Change the C++ constructor: set count_ to be 20
4.5 Repeat 4.2 and 4.3

See If It Works
File otcl.tcl
Run the file otcl.tcl
http://www.ns2ultimate.com set ns [new Simulator] set obj [new MyOTclObject ] puts "The variable count is [$obj set ocount_ ]"

See If It Works
Modify the constructor
Run the file otcl.tcl again
The change was made in the C++ domain ( MyObject::count_ ); The effect was carried over to the OTcl domain ( MyOTclObject::ocount_ )
http://www.ns2ultimate.com MyObject::MyObject() { bind("ocount_",&count_); count_ = 20; }

For more information about NS 2 Please see this book from Springer T. Issaraiyakul and E. Hossain, “Introduction to Network Simulator NS2”, Springer 2009 http://www.ns2ultimate.com

http://www.ns2ultimate.com	535
http://t-issariyakul.blogspot.com	232
http://t-issariyakul.blogspot.in	48
http://www.t-issariyakul.blogspot.com	11
http://www.t-issariyakul.blogspot.in	4
http://www.tumblr.com	2
http://t-issariyakul.blogspot.fr	1
http://t-issariyakul.blogspot.com.au	1
http://t-issariyakul.blogspot.it	1
http://t-issariyakul.blogspot.co.uk	1

NS2: Binding C++ and OTcl variables

by Teerawat Issariyakul on Jul 04, 2010

Accessibility

Categories

Tags

Upload Details

Usage Rights

10 Embeds 836

Statistics

NS2: Binding C++ and OTcl variables — Presentation Transcript