Write a concurrent program using parbegin-parend and semaphores to represent the precedence constraints of the statements S₁ to S₆, as shown in figure below.

At a particular time of computation the value of a counting semaphore is 7. Then 20 P operations and 15 V operations were completed on this semaphore. The resulting value of the semaphore is:

Given below is a program which when executed spawns two concurrent processes:

semaphore X := 0 ; 
/* Process now forks into concurrent processes P1 & P2 */
P1: repeat forever               P2: repeat forever
    V(X);                            P(X);  
    Compute;                         Compute; 
    P(X);	                     V(X); 

Consider the following statements about processes P1 and P2:
I. It is possible for process P1 to starve.
II. It is possible for process P2 to starve.
Which of the following holds?

Consider the following program segment for concurrent processing using semaphore operators P and V for synchronization. Draw the precedence graph for the statements S1 to S9.

 var
 a, b, c, d, e, f, g, h, i, j, k : semaphore;
 begin
 cobegin
    begin S1; V(a); V(b) end;
    begin P(a); S2; V(c); V(d) end;
    begin P(c); S4; V(c) end; 
    begin P(d); S5; V(f) end;
    begin P(e); P(f); S7; V(k) end;
    begin P(b); S3;V(g);V(h) end;
    begin P(g); S6; V(i) end;
    begin P(h); P(i); S8; V(j) end;
    begin P(j); P(j); P(k); S9 end;
 coend
 end;