os_kernel/test/thread_test.c

// /usr/bin/gcc -g -Wall -Wextra -Werror -std=c17 -o thread_test.bin thread_test.c -lpthread
#include <stdio.h>
#include <pthread.h>
#include <unistd.h>

void *thread_function(void *_arg)
{
    unsigned int *arg = (unsigned int *)_arg;
    printf(" new thread: my tid is %u\n", *arg);
    return NULL;
}

int main()
{
    pthread_t thread;
    pthread_create(&thread, NULL, thread_function, &thread); // pass the thread id to the new thread
    printf("main thread: my tid is %lu\n", (unsigned long)pthread_self());
    usleep(2000);
    return 0;
}