HotplugAgent.h

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Library General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * HotplugAgent.h
 * Handles auto-detection of USB devices.
 * Copyright (C) 2015 Simon Newton
 */

#ifndef LIBS_USB_HOTPLUGAGENT_H_
#define LIBS_USB_HOTPLUGAGENT_H_

#include <libusb.h>
#include <ola/Callback.h>
#include <ola/thread/PeriodicThread.h>

#include <map>
#include <memory>

#include "libs/usb/LibUsbAdaptor.h"
#include "libs/usb/LibUsbThread.h"
#include "libs/usb/Types.h"

namespace ola {
namespace usb {

class HotplugAgent {
 public:
  enum EventType {
    DEVICE_ADDED,   
    DEVICE_REMOVED,   
  };

  typedef ola::Callback2<void, EventType, struct libusb_device*>
      NotificationCallback;

  HotplugAgent(NotificationCallback* notification_cb,
               int debug_level);

  ~HotplugAgent();

  AsynchronousLibUsbAdaptor *GetUSBAdaptor() const;

  bool Init();

  bool Start();

  void HaltNotifications();

  bool Stop();

  #ifdef HAVE_LIBUSB_HOTPLUG_API

  void HotPlugEvent(struct libusb_device *dev,
                    libusb_hotplug_event event);
  #endif  // HAVE_LIBUSB_HOTPLUG_API

 private:
  typedef std::map<USBDeviceID, struct libusb_device*> DeviceMap;

  std::auto_ptr<NotificationCallback> const m_notification_cb;
  const int m_debug_level;
  bool m_use_hotplug;
  libusb_context *m_context;
  std::auto_ptr<ola::usb::LibUsbThread> m_usb_thread;
  std::auto_ptr<ola::usb::AsynchronousLibUsbAdaptor> m_usb_adaptor;
  std::auto_ptr<ola::thread::PeriodicThread> m_scanner_thread;

  ola::thread::Mutex m_mutex;
  bool m_suppress_hotplug_events;  // GUARDED_BY(m_mutex);

  // In hotplug mode, this is guarded by m_mutex while
  // m_suppress_hotplug_events is false.
  // In non-hotplug mode, this is only accessed from the scanner thread, unless
  // the thread is no longer running in which case it's accessed from the main
  // thread during cleanup
  DeviceMap m_devices;

  bool HotplugSupported();
  bool ScanUSBDevices();

  DISALLOW_COPY_AND_ASSIGN(HotplugAgent);
};
}  // namespace usb
}  // namespace ola
#endif  // LIBS_USB_HOTPLUGAGENT_H_