ptr_test.c

#include <stdio.h>
#include <unistd.h>

typedef struct widget {
  double value;
} widget;

void printval(int pid, double val)
{
  printf("pid: %d value: %f\n", pid, val);
}

void split(widget *w)
{
  int pid = fork();
  if (pid) {
    w->value = 0.2;
    printval(pid, w->value);
    sleep(1);
  } else {
    sleep(1);
    printval(pid, w->value);
  }
}

int main()
{
  widget w;
  split(&w);
}