Do Exercise 13 on page 238.
Also write a driver IntSetDriver.java that has a main
method that tests the IntSet class to make sure it works.
You will be partly graded on how well your code tests the ADT.
For this part of the homework, you will implement a mark-sweep collector. The framework of the problem is provided in two files: Client.java which uses the heap manager, and HeapManager which defines it. These files are in
/afs/cs.uwm.edu/users/classes/cs431/src/homework7/The
HeapManager class is incomplete. You need to define the
code to look for a block in the free list, and the code to perform
the mark-sweep garbage collection.
Unlike the code in the book, each cell in the memory is either an
Integer object or a Pointer object. In order to tell
which you have, you will need to use instanceof checks and
casts.
For instance, to determine if the memory pointed to by a pointer is an
Integer object, one may write:
p.peek(0) instanceof IntegerTo assume that it is an
Integer object, one writes:(Integer)p.peek(0)An
Integer object is not very useful. In order to get the
int value out, one will need to write((Integer)p.peek(0)).intValue()(The
peek method is defined in the class
HeapManager.Pointer and accesses memory using the pointer p.)
In this system, we represent null pointers by a Pointer
object with a -1 address.
In a mark-sweep collector (described on page 265), the collector
starts from the ``root'' pointer (which will be the current frame
pointer) and traverses the heap links marking every heap location that
is accessible. It uses the size of allocated blocks, and traverses
Pointer values, but not Integer values. You may assume
that all non-null pointers point to the beginning of a block. The
allocator should ensure that the size of the block is stored just
before the beginning of each block.
You submit your program work by putting it in the homework7 directory
in your AFS class volume.
You may do all your work in this directory, or you may wish to do your
work in a different directory and copy things when correct into this
directory. In any case, you will lose permission to write things in
this directory after the deadline, which is 4:00pm on Tuesday,
March 30. In other words, you must be done before lecture
starts.
The homework7 directory should include the following:
There are no paper problems associated with this homework.