nuttx-apps/system/usbmonitor/usbmonitor.c

/****************************************************************************
 * apps/system/free/free.c
 *
 *   Copyright (C) 2013 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * 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 <nuttx/progmem.h>

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

/****************************************************************************
 * Private Typs
 ****************************************************************************/

struct usbmon_state_s
{
#ifdef CONFIG_NSH_BUILTIN_APPS
  volatile bool started;
  volatile bool stop;
  pid_t pid;
#endif
};

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

static struct usbmon_state_s g_usbmonitor;

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

static int usbmonitor_daemon(int argc, char **argv)
{
#ifdef CONFIG_NSH_BUILTIN_APPS
  print("USB Monitor running: %d\n", g_usbmonitor.pid);
#endif

#ifdef CONFIG_NSH_BUILTIN_APPS
  /* If we are running as an NSH command, then loop until we detect that
   * there is a request to stop.
   */

  while (!g_usbmonitor.stop)
#else
  /* If we are running as a standalone program, then loop forever */

  for (;;)
#endif
    {
#warning "Missing logic"
    }

  /* Stopped */

#ifdef CONFIG_NSH_BUILTIN_APPS
  g_usbmonitor.stop    = false;
  g_usbmonitor.started = false;
  print("USB Monitor stopped: %d\n", g_usbmonitor.pid);
#endif
  return 0;
}

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

int usbmonitor_main(int argc, char **argv)
{
#ifdef CONFIG_NSH_BUILTIN_APPS
  /* Has the monitor already started? */

  sched_lock();
  if (!g_usbmonitor.started)
    {
      int ret;

      /* No.. start it now */
 
      g_usbmonitor.started = true;
      g_usbmonitor.stop    = false;

      ret = TASK_CREATE("USB Monitor", CONFIG_SYSTEM_USBMONITOR_PRIORITY,
                        CONFIG_SYSTEM_USBMONITOR_STACKSIZE,
                        (main_t)usbmonitor_daemon, (const char **)NULL);
      if (ret < 0)
        {
          int errcode = errno;
          fprintf(stderr, "ERROR: Failed to start the USB monitor: %d\n",
                  errcode);
        }
      else
        {
          g_usbmonitor.pid = ret;
          print("USB Monitor started: %d\n", g_usbmonitor.pid);
        }

      sched_unlock();
      return 0;
    }

  sched_unlock();
  print("USB Monitor running: %d\n", g_usbmonitor.pid);
  return 0;
#else
  return usbmonitor_daemon(argc, argv);
#endif
}

#ifdef CONFIG_NSH_BUILTIN_APPS
int usbmonitor_stop(int argc, char **argv)
{
  /* Has the monitor already started? */

  if (g_usbmonitor.started)
    {
      print("USB Monitor stopping: %d\n", g_usbmonitor.pid);
      g_usbmonitor.stop = true;
      return 0;
    }

  print("USB Monitor stopped: %d\n", g_usbmonitor.pid);
  return 0;
}
#endif