• İhsan Doğramacı Bilkent University

• CS 342

Q1. We have the following program. What are the pairs of values printed out by this program?

int a = 300;

int b = 100;

int ret;

int main()

{

ret = fork();

a = a + 10;

if (ret == 0) {

a = a * 2;

b = b + 50;

printf ("%d %d\n", a, b);

if (fork() == 0) {

a = a + 1000;

printf ("%d %d\n", a, b);

exit(0);

}

b = b + 10;

}

else {

a = a + 200;

b = 7 * b;

printf ("%d %d\n", a, b);

b = b + 80;

}

printf ("%d %d\n", a, b);

} Q 2. Consider the following program. What are the values that are printed out by this program?

unsigned long x = 1000;

unsigned long y = 2000;

unsigned long z = 400;

void * func1(void *p)

{

unsigned long x, z;

x = 1300;

y = 3000;

z = *((unsigned long *)p);

z = z + 300;

*((unsigned long *)p) += 500;

printf ("%lu %lu %lu\n", x, y, z);

2

pthread_exit(NULL);

}

int

main()

{

pthread_t tid;

unsigned long a = 5000;

pthread_create (&tid, NULL, &func1, (void *)&a);

pthread_join(tid, NULL);

printf ("%lu %lu %lu\n", x, y, z);

} Q 3. Consider the following program. Find out the triples printed out by this program. What can you say about their order?