noc-tools.md

noc-tools User Manual

noc-tools is implemented as a collection of TCL modules, implemented in both pure TCL and as C extensions for performance critical code. At present, there are two major modules:

• nocsim -- a simulation engine for simulating NoCs
• nocviz -- a general-purpose visualization tool oriented towards NoCs

A script is provided to automatically import (via package require) all noc-tools packages, which is located in the scripts/ directory. You should access it using the source command in a TCL interpreter, for example: source /path/to/noc-tools/scripts/noc_tools_load.tcl.

For those seeking an interactive TCL scripting environment, eltclsh is recommended.

Debugging Methodology

TCL has had a variety of debuggers and debugging approaches over it's long life. Any debugging approach that works within an embedded TCL instance should work correctly with nocsim. However, for your convenience, an approach to TCL script debugging is discussed and documented here.

TclPro was once a popular distribution of TCL and associated tools which retailed for a hefty price tag. It was eventually open sourced, but waned in popularity and languished in obscurity for some time. Eventually, the TclPro debugger was forked by FlightAware, LLC and updated for TCL 8.5 and higher. This updated version of TclProDebug is recommended for use with nocsim, and compatibility is specifically tested as it is used as part of the nocsim development process.

For the purposes of this document, it is assumed that TclProDebug is installed in /opt/TclProDebug. You may need to adjust some steps according to it's actual install location on your system.

First, you should start a debugging session by running /opt/TclProDebug/bin/prodebug, selecting File->New Project. Make sure to select "Remote Debugging" in the dialog window, then click "Apply".

Next up, you will want to wrap your TCL code you would like to debug in a debugger_eval block. Consider this example file:

source /opt/TclProDebug/lib/tcldebugger/initdebug.tcl
debugger_init
debugger_eval {
	debugger_break
	set x 5
	set y 10
	set z 11
	puts "value of z is $z"
}
debugger_break

If you save this file and source it from within a nocsim interpreter, it should automatically connect to your running instance of TclProDebug, and you should see the code appear in your TclProDebug window. It should look something like this:

You can now inspect variables via the interactive inspection tool, and single step your code or allow it to run until it hits a breakpoint.

TIP you can leave your debugging code in even after development has completed -- if TclProDebug is not running on your system, debugger_break does nothing, and debugger_eval acts like eval.

For more information, you may wish to consult the TclPro User's Guide.