Problem 1

1. Briefly describe the differences between traps and interrupts.
   
   
2. Many architectures rank interrupts in terms of priorities. What do these priorites represent? Why is this a useful thing to do?

Problem 2

int in0 = 0, in1 = 0;
cobegin
while (1) {
  in0 = 1;
  while (in1) {
    in0 = 0;
    while (in1) ;
    in0 = 1;
    }
  critical section
  in0 = 0;
  }
||
while (1) {
  in1 = 1;
  while (in0) {
    in1 = 0;
    while (in0) ;
    in1 = 1;
    }
  critical section
  in1 = 0;
  }
coend

1. Does the solution satisfy the safety property of the mutual exclusion problem? If so, then give an informal argument saying why. If not, then give an adversary schedule that violates safety.
   
   
2. Does the solution satisfy the liveness property of the mutual exclusion problem? If so, then give an informal argument saying why. If not, then give an adversary schedule that violates liveness.

Problem 3

1. Define a state of this system as a set of variables.
   
   
2. Give two safety properties of this system.
   
   
3. Give two liveness properties of this system.