Multi thread in c

// gcc -pthread th.c
#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>

void *entry_point(void *value) {
    int *num = (int *) value;
    int nth = *num;
    printf("thread%d (id : %ld) are run!\n", nth, pthread_self());

    if (*num > 3) {
        *num += 400;
        pthread_exit(value);
    }

    if (*num == 3) *num += 200;

    long i = 0;
    long d = 100000000;
    long max = (*num==1)? 100000000000 : 1000000000;
    while(i < max) {
        if (i%d == 0) printf("msg from thread%d (i = %ld)\n", nth, i);
        i++;
    }

    if (*num == 203) *num += 10;
    else if (*num <= 2) *num += 200;
}

int main(int argc, char **argv) {
    pthread_t thread1;
    pthread_t thread2;

    printf("main thread (id : %ld) are run!\n", pthread_self());

    // 4 for test thread exit
    // 1 for test normal thread
    int num1 = 1; 
    // 3 for test thread change args value without exit
    // 2 for cancel first thread
    int num2 = 2;

    pthread_create(&thread1, NULL, entry_point, &num1);
    pthread_create(&thread2, NULL, entry_point, &num2);

    //// for join one thread (wait end of this thread for continue)
    //pthread_join(thread1, NULL);
    while (1) {
        if (num2 > 200 && num2 < 400) pthread_cancel(thread1);
        if (num2 == 202 || num2 == 213) break;
    }
    printf("arg thread1 : %d, arg thread2 : %d\n", num1, num2);

    printf("close main thread\n");
    return EXIT_SUCCESS;
}