does fork() process share global variables

Hi all,
As what i know when you fork() a process, parent process and child process will be able to access the same global variables.
But i'm having the issue that when i changes some values in the child process, parent process isn't taking the changed values instead it still getting the same value as i initialized at first?
Can anyone explain to me why is this happening, or do i mistaken anything?
Thanks in advance.

this code contains race condition.

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

int x;
int y;

int main(void)
{
	pid_t pid;	
	if( (pid = fork()) < 0)
	{
		perror("Fork error");
		exit(1);
	}

	else if( pid == 0)
	{
		if (x == 0)
		{
			y = x + 1;
		}
		else
		{
			y = 5;
		}
		printf("child: x = %d y = %d\n", x, y);
	}
	
	else
	{
		if (y == 0)
		{
			x = y + 1;
		}
		else
		{
			x = 5;
		}
		printf("parent: x = %d y = %d\n", x, y);
	}

	exit(0);
}

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output:

child: x = 0 y = 1
parent: x = 1 y = 0 <--if child runs first, shouldn't the parent x = 5 y = 1???