Aspect-Oriented Software Development (Advanced Object-Oriented Systems)

COM 3362						Fall 2002

Homework 1
==========

Due date: Jan. 15.

AspectJ can be used in two phases: first for development aspects, then
for production aspects. In hw 1 we focus on development aspects.

SETUP:
Follow: http://www.ccs.neu.edu/home/lieber/com3362/w02/CCS_AspectJ_Usage.html

Put the file rt.jar into your class path as described 
at the beginning of:

http://www.ccs.neu.edu/research/demeter/software/docs/install.html


PART 1:
=======

The starting point is the Java program in:

/proj/adaptive2/course/com3360/f01/hw/1/graph/gen

We want to do some simple statistics for the execution of this program.

Write a Trace aspect that counts 
the number of method calls
the number of constructor calls
the number of field accesses
the number of field modifications

Hint:
the number of method calls: call(* *(..)) && !within(Trace)

Your program should print the output in a form similar to:

the number of method calls: : 10000
the number of constructor calls: 5000
the number of field accesses: 2000000
the number of field modifications: 700

Run your program with the input in

/proj/adaptive2/course/com3360/f01/hw/1/graph/class-graph.input by using:

java Main <../class-graph.input > out &

Turn in your program and the output it produced.


PART 2:
=======

Add a second aspect PTrace that executes for each constructor call:
System.out.println("Created a new object " + thisJoinPoint);

Use both Trace and PTrace simultaneously. How can you control 
which aspect to apply first? Explain. Does it matter in this case?

Run your program with the same input as in Part 1.

Turn in your aspect and an explanation of how you can order aspects.


PART 3:
=======

Consider the following aspect:

aspect Diff {
  pointcut thisPC(Vertex c) : this(c);
  pointcut targetPC(Vertex c) : target(c); 
  
   before(Vertex c):
     thisPC(c){
       System.out.println("ThisPC give ==> "+ thisJoinPoint+c );
     }
 
   before(Vertex c):
     targetPC(c){
       System.out.println("TargetPC gives ---------> " +thisJoinPoint + c  );
     }
 }
 
Explain how the two pointcuts differ.
Turn in your explanation.


PART 4:
=======

Above we were counting the number of method calls in the
execution of a Java program. How would you write a
Java program tha counts the number of methods contained
in a given Java program? 

static question: count number of methods in program
dynamic question: count number of method calls during execution of program

The dynamic question was answered above. Describe the design
of an aspect-oriented program that answers the static question.
Keep it brief.

Turn in your design.


Acknowledgements:
PART 1 - PART 3 tested by Therapon Skotiniotis.