III. Consider the following program:

int count = 1; //shared variable since its global

void twiddledee() {

int i=0; //for part b this will be global and shared

for (i=0; i<2; i++) {

count = count*3; //assume count read from memory once

}

}

void twiddledum() {

int i=0; // for part b, this will be global and shared

for(i=0; i<2; i++) { count = count - 1;}

}

void main() {

thread_fork(twiddledee); //new thread starts twiddledee

twiddledum(); //main thread calls twiddledum

thread_join(); //waits until all the threads get here

print count; }

a) What are all the values that could be printed in main?

b) Repeat part 1 considering that i is also a shared variable (Bonus 3 points tricky!)

c) Describe a potential schedule of execution (i.e., how the threads interleave running) under the original assumptions where i is not shared that will result in the value printed out being equal to -3.