#include <sys/ipc.h>
#include <sys/sem.h>
#include <sys/shm.h>
#include <stdio.h>
#include <stdlib.h>
#include "se207_sems.h"

/* Remember to try reversing the timings...*/


int bufferlength = 8; //Limited buffer length
//what could we do about this?

int main(int argc, char argv[]){

	//Create shared memory segment
	int shm_id = shmget(ftok("prodcon_example2.c", 2), bufferlength,
		0666 | IPC_CREAT);

	int shm_id2 = shmget(ftok("prodcon_example2.c", 3), 2,
		0666 | IPC_CREAT);

	//Use our source file as the "key"
	int id = se207_semget("prodcon_example2.c", 0);

	char* data; //For our pointer to shared memory...
	char* location;

	int pid = fork();
	if (pid){
		//P1 - CONSUMER
		shm_id = shmget(ftok("prodcon_example2.c", 2), 0, 006);
		shm_id2 = shmget(ftok("prodcon_example2.c", 3), 0, 006);
		//Attach the shared buffer
		data = shmat(shm_id, (void *)0, 0);
		location = shmat(shm_id2, (void *)0, 0);
		while (1){
			while (location[0] = location[1]){
			}
			//printf("Consuming item number %d...\n", location[1]);
			printf("consuming");
			sleep(1);
			//char item = data[location[1]];

			//printf("Consumed item number %d.  Item value was %d\n",
				//location[1], item);
			//location[1] = (location[1] + 1) % bufferlength;
		}
	}
	else{
		//P2
		shm_id = shmget(ftok("prodcon_example2.c", 2), 0, 006);
		shm_id2 = shmget(ftok("prodcon_example2.c", 3), 0, 006);
		//Attach the shared buffer
		data = shmat(shm_id, (void *)0, 0);
		location = shmat(shm_id2, (void *)0, 0);
		while(1){
			while ((location[0] + 1) % bufferlength == location[1]){
			}
			//printf("Producing item number %d...\n", location[0]);
			printf("Producing array size %d... value =%d consumer value =%d\n", sizeof(location),location[0], location[1]);
			sleep(2);
			//data[location[0]] = location[0] * 2; //Simple data, easy to check.
			//location[0] = (location[0] + 1) % bufferlength;
			//printf("Produced item number %d.  Value is %d\n",
				//location[0], data[location[0]]);
		}
	}
}