Consider the procedure below for the Producer-Consumer problem which uses semaphores:

semaphore n = 0;
semaphore s = 1;
void producer()
{
    while(true)
    {
     produce();
     semWait(s);
     addToBuffer();
     semSignal(s);
     semSignal(n);
    }
}

void consumer()
{
   while(true)
   {
    semWait(s);
    semWait(n);
    removeFromBuffer();
    semSignal(s);
    consume();
   }
}

Which one of the following is TRUE?

An operating system uses the Banker’s algorithm for deadlock avoidance when managing the allocation of three resource types X, Y, and Z to three processes P0, P1, and P2. The table given below presents the current system state. Here, the Allocation matrix shows the current number of resources of each type allocated to each process and the Max matrix shows the maximum number of resources of each type required by each process during its execution. There are 3 units of type X, 2 units of type Y and 2 units of type Z still available. The system is currently in a safe state. Consider the following independent requests for additional resources in the current state:

REQ1: P0 requests 0 units of X, 0 units of Y and 2 units of Z
REQ2: P1 requests 2 units of X, 0 units of Y and 0 units of Z

Which one of the following is TRUE?

A system has n resources R₀,.....,R_n-1, and k processes P₀,.....,P_k-1. The implementation of the resource request logic of each process P_i, is as follows:

if (i%2==0) {
  if (i < n) request Ri;
  if (i+2 < n) request Ri+2 ;
}
else {
  if (i < n) request Rn-i;
  if (i+2 < n) request Rn-i-2;
}

In which one of the following situations is a deadlock possible?

Consider a system with 4 types of resources R1 (3 units), R2 (2 units), R3 (3 units), R4 (2 units). A non-preemptive resource allocation policy is used. At any given instance, a request is not entertained if it cannot be completely satisfied. Three processes P1, P2, P3 request the sources as follows if executed independently. Which one of the following statements is TRUE if all three processes run concurrently starting at time t = 0?