/*
ECE 254 LAB 5
Student 1: Simon Chun Man Chan (ID: 20467509)
Student 2: Abdullah Hashmi (ID: 20485365)
Date: November 6, 2014
*/

#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <mqueue.h>
#include <sys/stat.h>
#include <time.h>
#include "common.h"
#include "point.h"
#include <wait.h>
#include <semaphore.h>

int num_int;
int producers;
int consumers;
int queue_size;
sem_t accessible;
sem_t blocked;
pthread_mutex_t mutex;
struct timeval tv;
double t1;
double t2;
int *global_buffer;
int production_count;
int consumption_count;


void *production(void *id){

	int counter = 0;
	int producer_id = (int)(intptr_t)id;


	for(counter = id; counter<queue_size; counter+=producers)
	{

			sem_wait(&blocked);
			pthread_mutex_lock(&mutex);//once getting access, lock the array
			global_buffer[production_count] = counter; //send data
			production_count = (production_count + 1) % queue_size; //increment so it is ready next time we send data.
			pthread_mutex_unlock(&mutex); //unlock for other processes
			sem_post(&accessible); //inform consumer that data is in array

	}
}

void *consumption(void *id){

	int counter = 0;
	int consumer_id = (int)(intptr_t)id;
	int consumed_integer;

	//LOOP: start at id, and send jumps of p to the buffer (for i%P effect)

	while(1){
			if (sem_trywait(&total) == -1){
				break;
			}
			sem_wait(&accessible);
			pthread_mutex_lock(&mutex);//once getting access, lock the array
			consumed_integer = global_buffer[consumption_count]; //send data
			consumption_count = (consumption_count + 1) % queue_size; //increment so it is ready next time we send data.

			if (sqrt(consumed_integer) % 1.0 == 0.0)
			{
				printf("%d %d %d\n", consumer_id, consumed_integer,(int)sqrt(consumed_integer));
			}

			pthread_mutex_unlock(&mutex); //unlock for other processes
			sem_post(&blocked); //inform consumer that data is in array
	}
}


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

	//if exactly 5 arguments are passed
	if (argc == 5) {

		num_int = atoi(argv[1]);
		queue_size = atoi(argv[2]);
		producers = atoi(argv[3]);
		consumers = atoi(argv[4]);


		if ((num_int && queue_size && producers && consumers) != 0){ //if the two parameters are integers

			pthread_t P_buffer[producers];
			pthread_t C_buffer[consumers];

			sem_init (&accessible, 0, 0);
			sem_init (&blocked, 0, queue_size);
			sem_init (&total, 0, num_int);

			global buffer = (int *)malloc(sizeof(int)*queue_size);

			gettimeofday(&tv, NULL);
			t1 = tv.tv_sec + tv.tv_usec/1000000.0;
			int i, b, m b;
			for (i=0; i < producers; i++){
				pthread_create (&P_buffer[i],NULL,&production,(void *)(intptr_t)i);
			}

			for(b = 0; b < consumers; b++){
					pthread_create (&C_buffer[b], NULL,&consumption,(void *)(intptr_t)b);
			}

			for (m = 0; m < producers; k++){
				pthread_join(P_buffer[m],NULL);
			}

			for (n = 0; n < consumers; l++){
				pthread_join(C_buffer[n],NULL);
			}

			gettimeofday(&tv, NULL);
			t2 = tv.tv_sec + tv.tv_usec/1000000.0;

			printf("System Execution time: %f\n",t2-t1);
			return 0;
		}
	}


	else{ //if the incorrect number of parameters are passed, exit
		perror("Incorrect number of parameters. Only provide 4 integers.");
		exit(1);
	}
}