#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <unistd.h>
#include <sys/wait.h>


void* say_hello(void* data) {
    char *str;
    str = (char*)data;

    printf("%s\n", str);
    // return;
}

void main(int argc, char **argv) {
    pthread_t tp1, tp2, tc1, tc2;
    pid_t child_pid = 0;

    printf("HELLO WORLD!\n\n");
    child_pid = fork();
    if (child_pid == 0) {
        pthread_create(&tc1, NULL, say_hello, "First thread from child process");
        pthread_create(&tc2, NULL, say_hello, "Second thread from child process");

        pthread_join(tc1, NULL);
        pthread_join(tc2, NULL);
    } else {
        pthread_create(&tp1, NULL, say_hello, "First thread from parent process");
        pthread_create(&tp1, NULL, say_hello, "Second thread from parent process");

        pthread_join(tp1, NULL);
        pthread_join(tp2, NULL);
        wait(0);
    }
}