nuttx/examples/poll/poll_main.c

/****************************************************************************
 * examples/poll/poll_main.c
 *
 *   Copyright (C) 2008 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
 *
 * 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. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 THE
 * COPYRIGHT OWNER 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.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include <sys/types.h>
#include <sys/stat.h>

#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <pthread.h>
#include <fcntl.h>
#include <poll.h>
#include <errno.h>
#include <debug.h>

#include "poll_internal.h"

/****************************************************************************
 * Definitions
 ****************************************************************************/

/****************************************************************************
 * Private Types
 ****************************************************************************/

/****************************************************************************
 * Private Data
 ****************************************************************************/

/****************************************************************************
 * Private Functions
 ****************************************************************************/

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: user_initialize
 ****************************************************************************/

void user_initialize(void)
{
}

/****************************************************************************
 * Name: user_start
 ****************************************************************************/

int user_start(int argc, char *argv[])
{
  char buffer[64];
  ssize_t nbytes;
  pthread_t tid;
  int count;
  int fd;
  int ret;

  /* Test FIFO logic */

  message("\nuser_start: Creating FIFO %s\n", FIFO_PATH);
  ret = mkfifo(FIFO_PATH, 0666);
  if (ret < 0)
    {
      message("user_start: mkfifo failed: %d\n", errno);
      return 1;
    }

  /* Open the FIFO for blocking, write */

  fd = open(FIFO_PATH, O_WRONLY);
  if (fd < 0)
    {
      message("user_start: Failed to open FIFO %s for writing, errno=%d\n",
              FIFO_PATH, errno);
      return 2;
    }

  /* Start the listener */

 message("user_start: Starting poll_listener thread\n");

  ret = pthread_create(&tid, NULL, poll_listener, NULL);
  if (ret != 0)
    {
      message("user_start: Failed to create poll_listener thread: %d\n", ret);
      return 3;
    }

  /* Loop forever */

  for (count = 0; ; count++)
    {
      /* Send a message to the listener... this should wake the listener
       * from the poll.
       */

      sprintf(buffer, "Message %d", count);
      nbytes = write(fd, buffer, strlen(buffer));
      if (nbytes < 0)
        {
          message("user_start: Write failed: %d\n", errno);
          return 4;
        }

      message("user_start: Sent '%s' (%d bytes)\n", buffer, nbytes);
      msgflush();

      /* Wait awhile.  This delay should be long enough that the
       * listener will timeout.
       */

      sleep(WRITER_DELAY);
    }

  fflush(stdout);
  return 0;
}