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

pthread_mutex_t mtx = PTHREAD_MUTEX_INITIALIZER;

typedef struct{
    int first;
    int second;
    int ind;
}Pair;

Pair pair;
int has_ended = 0, n = 0;

void* count(void* my_pair){
    int first = ((Pair*)my_pair)->first;
    int second =((Pair*)my_pair)->second;
    int id = ((Pair*)my_pair)->ind;
    printf("On thread %d start the sum was: %d, first was %d, second was %d\n", id, n, first, second);
    pthread_mutex_lock(&mtx);
    n += first;
    n += second;
    pthread_mutex_unlock(&mtx);
    printf("On thread %d final the sum was: %d, first was %d, second was %d\n", id, n, first, second);
    return NULL;
}


int main(){
    pthread_t* tid;
    int size = 1;
    tid = (pthread_t*)malloc(size*sizeof(pthread_t));
    int i = 0;
    while(has_ended == 0){
        //srand(time(NULL));
        int r = rand() % 5;
        pair.first = r;
        r = rand()%5;
        pair.second = r;
        pair.ind = i;
        pthread_create(&tid[i], NULL, count, (void*)&pair);
        i++;
        if(n >= 20){
            has_ended = 1;
        }
        //n += 10;
        size ++;
        tid = (pthread_t*)realloc(tid, size*sizeof(pthread_t));
    }
    int j;
    for(j = 0; j<i; j++){
        pthread_join(tid[i], NULL);
    }
    free(tid);
    return 0;
}