#include <stdio.h>
#include <stdlib.h>
#include "lib.h"
#include <semaphore.h>
#include <unistd.h>
#include <time.h>
#include <sys/wait.h>

typedef struct {
        int cnt;
        int cnt2;
        sem_t sem;
        sem_t mutex;
        sem_t sem2;
}shared_str;

//global shared mem
shared_str *st;


void wall(int i, int n){
        for(int j = 0; j < 5; j++)
        {
        sem_wait(&st->mutex);
        st->cnt++;

        if(st->cnt == n){
                printf("prisiel posledny proces \n");
                sem_wait(&st->sem2);
                sem_post(&st->sem);
        }

        sem_post(&st->mutex);
        printf("proces c.[%d] caka\n", i);
        sem_wait(&st->sem);
        printf("proces c.[%d] ide dalej \n", i);
        sem_post(&st->sem);

        sem_wait(&st->mutex);
        st->cnt--;
        if(st->cnt == 0){
                printf("prisiel zasa posledny proces \n ");
                sem_post(&st->sem2);
                sem_wait(&st->sem);
        }

        sem_post(&st->mutex);

        sem_wait(&st->sem2);
        sem_post(&st->sem2);
        }


}

int main(){

        int n = 10;
        st = (shared_str*) malloc_shared(sizeof(shared_str));
        sem_init(&st->mutex     , 1, 1);
        sem_init(&st->sem       , 1, 0);
        sem_init(&st->sem2      , 1, 1);
        st->cnt = 0;
        st->cnt2 = 0;
        for(int i = 0; i < n; i++){
                printf("%d\n", i);
                switch(fork()){
                case -1:
                        perror("err fork\n");
                        exit(-1);
                        break;
                case 0:
                        wall(i, n);
                        return 0;
                        break;
                default:
                        break;
                }

        }

        for(int i = 0; i < n; i++){
                wait(NULL);
        }

        free_shared(st);

        return 0;
}