/*      $OpenBSD: select.c,v 1.4 2018/04/26 15:55:14 guenther Exp $     */
/*
 * Copyright (c) 1993, 1994, 1995, 1996 by Chris Provenzano and contributors, 
 * proven@mit.edu All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Chris Provenzano,
 *      the University of California, Berkeley, and contributors.
 * 4. Neither the name of Chris Provenzano, the University, nor the names of
 *   contributors may be used to endorse or promote products derived
 *   from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY CHRIS PROVENZANO AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL CHRIS PROVENZANO, THE REGENTS OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */ 

/*
 * Rudimentary test of select().
 */

#include <sys/types.h>
#include <sys/time.h>
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <pthread_np.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "test.h"

#define NLOOPS 10000

int ntouts = 0;

static void *
bg_routine(void *arg)
{
        char dot = '.';
        int n;

        SET_NAME("bg");

        /* Busy loop, printing dots */
        for (;;) {
                pthread_yield();
                write(STDOUT_FILENO, &dot, sizeof dot);
                pthread_yield();
                n = NLOOPS;
                while (n-- > 0)
                        pthread_yield();
        }
}

static void *
fg_routine(void *arg)
{
        int     flags;
        int     n;
        fd_set  r;
        int     fd = fileno((FILE *) arg);
        int     tty = isatty(fd);
        int     maxfd;
        int     nb;
        char    buf[128];

        SET_NAME("fg");

        /* Set the file descriptor to non-blocking */
        flags = fcntl(fd, F_GETFL);
        CHECKr(fcntl(fd, F_SETFL, flags | O_NONBLOCK));

        for (;;) {

                /* Print a prompt if it's a tty: */
                if (tty) {
                        printf("type something> ");
                        fflush(stdout);
                }

                /* Select on the fdesc: */
                FD_ZERO(&r);
                FD_SET(fd, &r);
                maxfd = fd;
                errno = 0;
                CHECKe(n = select(maxfd + 1, &r, (fd_set *) 0, (fd_set *) 0,
                                  (struct timeval *) 0));

                if (n > 0) {
                        /* Something was ready for read. */
                        printf("select returned %d\n", n);
                        while ((nb = read(fd, buf, sizeof(buf) - 1)) > 0) {
                                printf("read %d: `%.*s'\n", nb, nb, buf);
                        }
                        printf("last read was %d, errno = %d %s\n", nb, errno,
                               errno == 0 ? "success" : strerror(errno));
                        if (nb < 0)
                                ASSERTe(errno, == EWOULDBLOCK || 
                                    errno == EAGAIN);
                        if (nb == 0)
                                break;
                } else
                        ntouts++;
        }
        printf("read finished\n");
        return (NULL);
}

int
main(int argc, char *argv[])
{
        pthread_t       bg_thread, fg_thread;
        FILE *          slpr;

        /* Create a fdesc that will block for a while on read: */
        CHECKn(slpr = popen("sleep 2; echo foo", "r"));

        /* Create a busy loop thread that yields a lot: */
        CHECKr(pthread_create(&bg_thread, NULL, bg_routine, 0));

        /* Create the thread that reads the fdesc: */
        CHECKr(pthread_create(&fg_thread, NULL, fg_routine, (void *) slpr));

        /* Wait for the reader thread to finish */
        CHECKr(pthread_join(fg_thread, NULL));

        /* Clean up*/
        CHECKe(pclose(slpr));

        SUCCEED;
}