#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>

#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <unistd.h>
#include <sys/time.h>

static volatile int thread_exit = 0;

int thread_delay (unsigned int time_ms)
{
    usleep (time_ms * 1000);
    return 0;
}

int rand_r (unsigned int *seed)
{
        long k;
        long s = (long)(*seed);
        if (s == 0)
          s = 0x12345987;
        k = s / 127773;
        s = 16807 * (s - k * 127773) - 2836 * k;
        if (s < 0)
          s += 2147483647;
        (*seed) = (unsigned int)s;
        return (int)(s & RAND_MAX);
}

void * thread_func1 (void *arg)
{
int n;
#ifdef RANDOM
unsigned int randseed1 = 0xf00dface;
#endif

    n = (int)arg;
    fprintf (stdout, "Thread #%d enters tf1...\n", n);
    fflush (stdout);
    while (1)
    {
#ifdef RANDOM
        thread_delay (250 + (rand_r (&randseed1) * 256 / RAND_MAX));
#else
        thread_delay (313);
#endif
        fprintf (stdout, "W");
        fflush (stdout);
        if (thread_exit)
            break;
    }
    fprintf (stdout, "Leaving thread func1!\n");
    fflush (stdout);
    return (void *) 1UL;
}

void * thread_func2 (void *arg)
{
int n;
#ifdef RANDOM
unsigned int randseed2 = 0xf00dface;
#endif

    n = (int)arg;
    fprintf (stdout, "Thread #%d enters tf2...\n", n);
    while (1)
    {
#ifdef RANDOM
        thread_delay (250 + (rand_r (&randseed2) * 256 / RAND_MAX));
#else
        thread_delay (257);
#endif
        fprintf (stdout, "R");
        fflush (stdout);
        if (thread_exit)
            break;
    }
    fprintf (stdout, "Leaving thread func2!\n");
    fflush (stdout);
    return (void *) 2UL;
}


int main (int argc, const char **argv)
{
int rv;
pthread_t thr1, thr2;
void *tr1, *tr2;

    // spawn two threads.....
    rv = pthread_create (&thr1, NULL, thread_func1, (void *)1UL);
    if (rv)
        fprintf (stderr, "err %d create thr1\n", errno);

    rv = pthread_create (&thr2, NULL, thread_func2, (void *)2UL);
    if (rv)
        fprintf (stderr, "err %d create thr2\n", errno);

    fflush (stderr);

    // Only actually run if both threads started ok!
    if (!rv) while (1)
    {
        // Control thread: wait for user input and execute it
        char dummy[8];
        fprintf (stdout, "Press return/enter to terminate.....");
        fflush (stdout);
//        fflush (stdin);
//        scanf ("%*[^\r\n]%1[\r\n]", &dummy[0]);
        scanf ("%1c", &dummy[0]);
        fprintf (stderr, "****AFTER SCANF\n");
        // never loop... this is just a test after all....
        break;
    }

    thread_exit = 1;
    rv = pthread_join (thr1, &tr1);
    if (rv)
        fprintf (stderr, "pthr join errno1 %d\n", errno);
    else
        fprintf (stderr, "exit ok\n");

    rv = pthread_join (thr2, &tr2);
    if (rv)
        fprintf (stderr, "pthr join errno1 %d\n", errno);
    else
        fprintf (stderr, "exit 2 ok\n");

    fprintf (stderr, "thread exticodes $%8p $%8p\n", tr1, tr2);
    return 0;

}