Implement Reader-Writer problem using OPENMP

// Implement Reader-Writer problem using OPENMP (file name rw.c)
#include<stdio.h>
#include<omp.h>

main()
{
 int semaphore=0;
#pragma omp parallel num_threads(2)  // two thread are created;
{
  int i;
int tid=omp_get_thread_num();
do
{
 printf("\n thread %d\n%d.read\n%d.write\n5.exit",tid,tid*2,tid*2+1);

//0: read at thread0 ;
//1: write at thread 0;
// 2: read at thread 1;
//3: write at thread 1;
//5: exit thread .;
scanf("%d",&i);

switch(i)
{
case 0: if(semaphore==1)//thread 1 is writing;
         {
            while(semaphore==1)//wait untill semaphore becomes 0;
              {
                  printf("\n shared data is in use");
                sleep(1);
              }
          }


         printf("\n reading in thread 0");
         sleep(5);
         printf("\n reading done in thread 0");
         break;

case 1: if(semaphore==1)// thread 1 is writing

           {
                 while(semaphore==1)// wait until smaphore become 0
                 sleep(1);
          }
      

 semaphore=1;
printf("\n writing in thread 0");
sleep(5);
printf("\n writing done in thread 0");
semaphore=0;
break;


case 2:  if(semaphore==1)//thread 0 is writing
         {
            while(semaphore==1)//wait untill semaphore becomes 0
              {
                  printf("\n shared data is in use");
                sleep(1);
              }
          }

printf("\n reading in thread 1");
sleep(5);
printf("reading done in thread 1");
break;


case 3:  if(semaphore==1)//thread 0 is writing
         {
            while(semaphore==1)//wait untill semaphore becomes 0
              {
                  printf("\n shared data is in use");
                sleep(1);
              }
          }
    semaphore=1;

    printf("\n writing  in thread 1");
    sleep(5);
     printf("writing  done in thread 1");
    semaphore=0;

    break;
     }
     }
while(i<5);
}
}

-------------------------------------------------O/P--------------------------------------------------------------
test@test-ThinkCentre-M72e:~$ gcc rw.c -fopenmp
test@test-ThinkCentre-M72e:~$ ./a.out

 thread 1
2.read
3.write
5.exit
 thread 0
0.read
1.write
2
5.exit
 reading in thread 1
reading done in thread 1
 thread 1
2.read
3.write
3
5.exit
 writing  in thread 1
writing  done in thread 1
 thread 0
0.read
1.write
1
5.exit
 writing in thread 0

 writing done in thread 0
 thread 1
2.read
3.write
5
5.exit