The P and V operations on counting semaphores, where s is a counting semaphore, are defined as follows:

P(s): s = s-1; 
if s < 0 then wait; 
V(s) : s = s-1; 
ifs <= 0 then wakeup a process waiting on s;

Assume that P_b and V_b the wait and signal operations on binary semaphores are provided. Two binary semaphores X_b and Y_b are used to implement the semaphore operations P(s) and V(s) as follows:

  P(s): Pb (Xb);
        S = s - 1;
        if(s < 0){
          Vb(Xb);
          Pb(Yb);
        }
        Else Vb (Xb);
  V(s): Pb (Xb);
        S = s + 1;
        if(s <= 0) Vb(Yb);
        Vb(Xb);

The initial values of X_b and Y_b are respectively

Which of the following is/are true of the auto-increment addressing mode?
$${\rm I}.\,\,\,$$ It is useful in creating self-relocating code
$${\rm II}.\,\,\,$$ If it is included in an Instruction Set Architecture, then an additional $$ALU$$ is required for effective address calculation.
$${\rm III}.\,\,\,$$ The amount of increment depends on the size of the data item accessed

A process executes the following code

for (i = 0; i < n; i + +) fork ( ); 

The total number of child processes created is

What is printed by the following C program?

#include < stdio.h >
int f(int x, int *py, int **ppz)
{
   int y, z;
  **ppz += 1; 
   z  = **ppz;
  *py += 2;
   y = *py;
   x += 3;
   return x + y + z;
}
 
void main()
{
   int c, *b, **a;
   c = 4;
   b = &c;
   a = &b; 
   printf( "%d", f(c,b,a));
   getchar();
}