MCS 730
Parallel Programming I
Instructor Jeremy Johnson
Practice Assignment 1
Not to be handed in

1)  Exercise 4 of Chapter 3 of the textbook (CG). Test your program in
the following way:  
Write a main program that first creates a list in tuplespace and then 
evals several processes that simultaneously count the number of atoms in 
the list  (when finished counting, each process should print the total
number of atoms in the list).

A list should never be modified while another process is reading the list.
Nor should two processes be allowed to simultaneously modify a list.
How can you ensure that this never happens while still allowing multiple 
processes to simultaneously read the list?


2)  Implement a bounded buffer using Linda.  You should eval several
producer processes and a single consumer process.  The producer processes
should produce tuples of the form ("buffer",id), where id is some integer
that distinguishes each of the producer processes.  The consumer process
should read buffer tuples and print them out.  There should never be more
than N (some constant you can choose) buffer tuples in tuple space at any 
given time.  You should decide when the consumer process has obtained enough
tuples (e.g. a specified number of tuples have been consumed) and at that 
time the consumer process should inform the producer processes to stop 
production and quit.  When all producer 
processes have finished the consumer process should print a message.

You must guarantee that your program never enters
deadlock (e.g. if a producer is blocked due to a full buffer when the
consumer informs the producer to quit production deadlock will occur)