#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<sys/types.h>
#include<unistd.h>
#include "simpleipc.c"
#include <math.h>

void childfun(int pipe);
void parentfun(int pipe);

int main()
{ int result;
  pid_t procid;  // needed for fork
  int pfd[2];

  result = pipe(pfd);
  if (result<0) { printf("pipe creation failed\n"); exit(1);}

  procid = fork();
  
  if (procid == 0) childfun(pfd[0]);
    else parentfun(pfd[1]);
 
  exit(0);
}

// parent acts as server and serves x-squared to client(child)
void parentfun(int pipe)
{  int result;
   double x, y;  
   while (1<2)
     {
       printf("parent: ready to serve\n");
       result = read(pipe,&x,sizeof(double));
       y = x * x;
       write(pipe,&y,sizeof(double));
       for(result=0;result<25000000;result++) {}
     } // while
}  // parentfun

void childfun(int pipe)
{
   int result;
   double x,y;
   x = 2.0;
   while (x<10000.0)
     {
       write(pipe,&x,sizeof(double));
       result = read(pipe,&y,sizeof(double));
       if (result == sizeof(double))
	 {
           printf("child: received %.5f\n",y);
           x = y;
         }
       for(result=0;result<25000000;result++) {}
     }
   close(pipe);
} // childfun