#include <iostream>
#include <fstream>
#include <cmath>
#include <pthread.h>
#include <malloc.h>

#define RET_CODE(n) (void*)(n)
#define PRIME_RANGE 0xFFFF
#define THR_NUM 10

pthread_mutex_t lock,flock;
uint idx=2,n=0;

void* calculator(void* arg)
{
    uint i,k=1,z=0;
    bool is_prime = false;
    uint* primes = (uint*)calloc(PRIME_RANGE,
        sizeof(uint));
    if(!primes)
    {
        perror("calloc primes");
        RET_CODE(1);
    }
    while(idx<0xFFFFFFFF)
    {
        pthread_mutex_lock(&lock);
        i = idx;
        idx+=PRIME_RANGE;
        pthread_mutex_unlock(&lock);
        for(;i<(i+PRIME_RANGE); i++)
        {
            is_prime = true;
            for(uint j=2;j<=(uint)sqrt(i);j++)
            {
                if(j==i||i%j==0)
                {
                    is_prime = false;
                    break;
                }
            }
            if(is_prime)
            {
                if(z<PRIME_RANGE)
                    primes[z++] = i;
                else
                {
                    pthread_mutex_lock(&flock);
                    FILE* fp = fopen(
                     "/storage/emulated/0/prime.txt","ab");
                    for(uint c=0;c<z;c++)
                    {
                        fprintf(fp,"%u\t",
                            primes[c]);
                        if((c+1)%5==0)
                            putc('\n',fp);
                    }
                    fclose(fp);
                    printf("Prmes N %d\n",(n+=z));
                    pthread_mutex_unlock(&flock);
                    z=0;
                }
            }
        }
    }
    free(primes);
    RET_CODE(0);
}

int main()
{
    pthread_t thr[THR_NUM];

    pthread_mutex_init(&lock,NULL);
    pthread_mutex_init(&flock,NULL);

    for(uint l=0;l<THR_NUM;l++)
        pthread_create(&thr[l],NULL,calculator,
            NULL);
    getc(stdin);

    pthread_mutex_destroy(&lock);
    pthread_mutex_destroy(&flock);
    return 0;
}