heis/elev-threaded/mastermod.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <pthread.h>
#include <time.h>

#include "localsys.h"
#include "mastermod.h"
#include "elev.h"
#include "globals.h"
#include "netmod.h"


role_t role = MASTER;
int master_sock;
int master_cand_sock = -1;
status_t *lhead = NULL;
status_t *llast = NULL;


void print_status(){
	status_t *it = lhead;
	printf("Online Elevators: ");
	while(it != NULL){
		printf("socket %d, role %d  |  ",it->sockid, it->role);
		it = it->next;
	}
	printf("\n");
}

void add_to_list(int sock){
	status_t *new_elev;
	new_elev = malloc(sizeof(status_t));
	new_elev->sockid = sock;
	new_elev->next = NULL;

	if (lhead == NULL){
		lhead = new_elev;
	}
	else {
		llast->next = new_elev;
	}
	llast = new_elev;
	print_status();
}

int get_master_cand_sock() {
	return master_cand_sock;
}

void set_alive(int sock, int b) {
	status_t *it = lhead;
	while(it != NULL){
		if (it->sockid == sock) {
			it->alive = b;
			return;
		}	
		it = it->next;
	}
}

role_t get_role() {
	return role;
}
void set_role(role_t r) {
	role = r;
}

int get_master_sock() {
	return master_sock;
}

void set_master_flag() {
	lhead->sockid = -1;
}

void set_master_sock(int sock) {
	master_sock = sock;
}

void print_elevs() {
	status_t *it = lhead;
	printf("Elevator list: ");
	while(it != NULL){
		printf("Socket %d, alive %d\n",it->sockid, it->alive);
		it = it->next;
	}
}

void add_elev(int sock){	
	status_t *new_elev;
	new_elev = malloc(sizeof(status_t));
	new_elev->sockid = sock;
	new_elev->floor = 0;
	new_elev->end_dest = 0;
	new_elev->state = STOPPED;
	new_elev->alive = 1;
	new_elev->next = NULL;

	if (lhead == NULL){
		lhead = new_elev;
		new_elev->role = MASTER;
	}
	else {
		llast->next = new_elev;
		new_elev->role = SLAVE;
	}
	llast = new_elev;
	print_elevs();
}

void master_init(int s) {
	add_elev(s);
	lhead->role = MASTER;
	lhead->alive = 1;
}

void add_slave(int sock) {
	add_to_list(sock);
	
	llast->floor = 0;
	llast->state = STOPPED;	
	llast->alive = 1;
	llast->end_dest = 0;
	
	if (master_cand_sock == -1) {
		master_cand_sock = sock;
		llast->role = MASTER_CAND;
	}
	else llast->role = SLAVE;
}

void set_elev_state(int sock, char str[]) {
	status_t *it = lhead;
	while(it != NULL){
		if (it->sockid == sock) {
			it->state = (int) str[1];
			it->floor = (int) str[2];
			it->end_dest = (int) str[3];
			return;
		}
		
		
		it = it->next;
	}
}

int find_opt_elev(int call, int floor) {
	int best = abs(floor - lhead->floor);
	status_t *res = lhead;
	status_t *it = lhead->next;
	int dir = lhead->end_dest-lhead->floor;
	
	int passing = 0;
	int idle = 0;
	
	while (it != NULL) {
		if (((!it->alive) || (it->end_dest == -1))) {
			it = it->next;
			continue;
		}
		dir = it->end_dest-it->floor;
		
		if (((dir > 0) && (floor > it->floor) && (floor <= it->end_dest) && (call != ELEV_DIR_DOWN)) || 
			((dir < 0) && (floor < it->floor) && (floor >= it->end_dest) && (call != ELEV_DIR_UP))) {
			if (abs(floor - it->floor) < best) {
				res = it;
				best = abs(floor - it->floor);
				passing = 1;
			}
		}
		it = it->next;
	}
	
	if (!passing) {
		it = lhead;
		best = N_FLOORS+1;
		while (it != NULL) {
			if (!it->alive) {
				it = it->next;
				continue;
			}
			if ((it->state == IDLE) && (abs(floor - it->floor) < best)) {
				best = abs(floor - it->floor);
				res = it;
				idle = 1;	
			}
			else if ((!idle) && (abs(floor - it->floor) < best)){
				best = abs(floor - it->floor);
				res = it;
			}
			it = it->next;
		}
		
	}	
	return res->sockid;
}