LibUsbThread.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.
 *
 * LibUsbThread.h
 * The thread for asynchronous libusb communication.
 * Copyright (C) 2014 Simon Newton
 */

#ifndef LIBS_USB_LIBUSBTHREAD_H_
#define LIBS_USB_LIBUSBTHREAD_H_

#include <libusb.h>

#if HAVE_CONFIG_H
#include <config.h>
#endif  // HAVE_CONFIG_H

#include "ola/base/Macro.h"
#include "ola/thread/Thread.h"

namespace ola {
namespace usb {

class LibUsbThread : private ola::thread::Thread {
 public:
  explicit LibUsbThread(libusb_context *context)
    : m_context(context),
      m_term(false) {
  }

  virtual ~LibUsbThread() {}

  virtual bool Init() {
    return true;
  }

  virtual void Shutdown() {}

  void *Run();

  virtual void OpenHandle() = 0;

  virtual void CloseHandle(libusb_device_handle *handle) = 0;

 protected:
  void SetTerminate() {
    ola::thread::MutexLocker locker(&m_term_mutex);
    m_term = true;
  }

  void LaunchThread();

  void JoinThread();

  libusb_context* Context() const { return m_context; }

 private:
  libusb_context *m_context;
  bool m_term;  // GUARDED_BY(m_term_mutex)
  ola::thread::Mutex m_term_mutex;
};

#if HAVE_LIBUSB_HOTPLUG_API

class LibUsbHotplugThread : public LibUsbThread {
 public:
  LibUsbHotplugThread(libusb_context *context,
                      libusb_hotplug_callback_fn callback_fn,
                      void *user_data);

  bool Init();

  void Shutdown();

  void OpenHandle() {}

  void CloseHandle(libusb_device_handle *handle);

 private:
  libusb_hotplug_callback_handle m_hotplug_handle;
  libusb_hotplug_callback_fn m_callback_fn;
  void *m_user_data;

  DISALLOW_COPY_AND_ASSIGN(LibUsbHotplugThread);
};

#endif  // HAVE_LIBUSB_HOTPLUG_API

class LibUsbSimpleThread : public LibUsbThread {
 public:
  explicit LibUsbSimpleThread(libusb_context *context)
    : LibUsbThread(context),
      m_device_count(0) {
  }

  void OpenHandle();
  void CloseHandle(libusb_device_handle *handle);

 private:
  unsigned int m_device_count;

  DISALLOW_COPY_AND_ASSIGN(LibUsbSimpleThread);
};
}  // namespace usb
}  // namespace ola
#endif  // LIBS_USB_LIBUSBTHREAD_H_