GeeksforGeeks

It was given 2^N-1

Please Explain!!

code snippet for mutex and semaphore?

Consider the following code snippet...

if (fork() == 0)
{
    a = a + 5;
    printf("%d, %d \n", a, &a);
}
else
{
    a = a - 5;
    printf ("%d, %d \n", a,& a);
}

Let u, v be the values printed by the parent process, and x, y be the values printed by the child process. Which one of the following is TRUE? [ a ? b means that the relationship between a and b cannot be determined and will depend on whether child runs first or parent runs first or some other factors]

volatile int a;

int main()
{
    a=10;
    volatile int *b=&a;
    volatile int c=11;
    if(vfork()==0)
    {
        a++;
        (*b)++;
        c++;
        printf("%d %d %d\n",a,*b,c);
        exit(0);
    }
    printf("%d %d %d\n",a,*b,c);
}

Assuming child process executes first
a) 12 12 12
12 12 12

b) 12 12 12
10 10 10

c) 10 10 10
10 10 10

d) None of these

whats the answer ....according ...

volatile int a;

int main()
{
a=10;
volatile int *b=&a; volatile int c=11;
if(vfork()==0) {
a++; (*b)++; c++;
printf("%d %d %d\n",a,*b,c);
exit(0); }
printf("%d %d %d\n",a,*b,c);
}
Assuming child process executes first
a) 12 12 12 b) 12 12 12
12 12 12 10 10 10

c) 10 10 10 d) None of these
10 10 10

what...

The size of Virtual Memory depends on the which of the following in Linux Operating System

a) Physical Memory b) Secondary Memory c)Both d) None of these

which option is correct and why???????

Why must be bitmap image for the file allocation be kept on mass storage rater then in main memory?

Q Consider the following snapshot of a system running n processes. Process i is
holding i x instances of a resource R, 1 £ i £ n. currently, all instances of R are
occupied. Further, for all i, process i has placed a request for an additional
i y instances while holding the i x instances it already has. There are exactly two
processes p and q such that 0. p q y = y = Which one of the following can serve as
a necessary condition to guarantee that the system is n...

i is a gobal variable with value 5 and function v() is called in by three threads.

v()
{i++;
i--;

}

what is the no. of possible outcomes of i and what are they.

What is the difference between an ORDERED and UNORDERED data structure?

A thread is usually defined as a ‘light weight process’ because an operating system (OS) maintains smaller data structures for a thread than for a process. In relation to this, which of the followings is TRUE?
(A) On per-thread basis, the OS maintains only CPU register state
(B) The OS does not maintain a separate stack for each thread
(C) On per-thread basis, the OS does not maintain virtual memory state
(D) On per thread basis, the OS maintains only scheduling an...

What must be the hit ratio in order to reduce the effective memory access time from 200ns to 140ns if tlb lookup time is 20ns

what is priority inversion in process scheduling?

What kind of operating system UNIX is? Preemptive or Non-Preemptive

Consider we have 4 processes P1, P2, P3 and P4 and consider the following table. Consider a < b < c < d where a, b, c and d is the execution time of P1, P2, P3 and P4 respectively.

Processes Execution Time
P1 a
P2 b
P3 c
P4 d

What is the average turnaround time when shortest job first CPU scheduling algorithm is used? (AKAMAI 2010 Engg – Set 3 – Q10) (LOW)
A) (3a + 4b + c + d) / 4
B) (4a + 3b + 2c + d) / 4

What is there inside the executable file ?

Two processes, P1 and P2, need to access a critical section of code. Consider the following synchronization construct used by the processes:

/* P1 */
while (true) {
  wants1 = true;
  while (wants2==true);
    /* Critical Section */
  wants1=false;
}
/* Remainder section */

/* P2 */
while (true) {
wants2 = true;
while (wants1==true);
/* Critical Section */
Wants2=false;
}
/* Remainder section */

Here, wants1 and wants2 are shared variables, which are initiali...