#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <time.h>
#include <unistd.h>

#define     DATA_SIZE       ((int)  100)
#define     NUM_THREADS     ((int)  40)
#define     NUM_SWAPS       ((int)   2000000)

int data[DATA_SIZE];

pthread_mutex_t m;

void *B(void *arg)
{
    while(1) {
        sleep(1);
        printf("*\n");
        int *instancount=(int*)malloc(sizeof(int)*DATA_SIZE);
        for(int i=0;i<DATA_SIZE;i++)
        {
            instancount[i]=0;
        }
        //pthread_mutex_lock(&m);
        for(int i=0;i<DATA_SIZE;i++)
        {
            instancount[data[i]]++;
        }
        //pthread_mutex_unlock(&m);
        int errors=0;
        for(int i=0;i<DATA_SIZE;i++)
        {
            if(instancount[data[i]]!=1)
                errors++;
        }
        if(errors>0)
            printf("Count Missing = %d\n",errors);
    }
}

//check that each number from 0 to n occurs exactly once in the array
pthread_t DataSpawn()
{
    pthread_t tid;
    pthread_attr_t attr;
    pthread_attr_init(&attr);
    pthread_create(&tid,&attr,B,NULL);
    //pthread_join(tid,NULL);
    return tid;
}

void swap(int *a, int *b)
{
    int temp;
    temp = *a;
    *a = *b;
    *b = temp;

}

void ZeroInit()// to do: change this name later
{
    for(int i=0;(i+3)<=DATA_SIZE+2;i++)
    {
        data[i]=i;
    }
}

void* A(void *arg)//
{
    int limit=NUM_SWAPS;
    int idx1=0;
    int idx2=0;
    //srand(time(NULL));
    for(int i=0;i<limit;i++)
    {
        idx1= rand()%DATA_SIZE;
        idx2= rand()%DATA_SIZE;
        //pthread_mutex_lock(&m);
        swap(&data[idx1],&data[idx2]);
        //pthread_mutex_unlock(&m);
    }
    //return 0;
    pthread_exit(0);
}



void SpawnThreads(unsigned int n)
{
    int ret=-1;
    pthread_t *threadArray=malloc(sizeof(pthread_t)*n);
    pthread_t checkerThread;
    for(int i=0;i<n;i++)
    {
        ret=pthread_create(&threadArray[i],NULL,A,NULL);
        if(ret != 0)
        {
            printf("Pthread error");
        }

    }
    checkerThread = DataSpawn();
    for(int i=0;i<n;i++)
    {
        pthread_join(threadArray[i],NULL);
    }
    pthread_cancel(checkerThread);
    pthread_join(checkerThread,NULL);
}





int main(int argc, char **argv)
{
    ZeroInit();
    pthread_mutex_init(&m,NULL);
    SpawnThreads(NUM_THREADS);
}