/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */

/*

 * Copyright (c) 2005 INRIA

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation;

 *

 * 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 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 *

 * Author: Mathieu Lacage <mathieu.lacage.inria.fr>

 */

#ifndef SYSTEM_WALL_CLOCK_MS_H

#define SYSTEM_WALL_CLOCK_MS_H

#include <stdint.h>

namespace ns3 {

/**

 * \brief measure elapsed time in milliseconds

 *

 */

class SystemWallClockMs {

public:

  SystemWallClockMs ();

  ~SystemWallClockMs ();

  /**

   * Start a measure.

   */

  void Start (void);

  /**

   * \brief Stop measuring the time since Start() was called.

   * \returns the measured elapsed wall clock time (in milliseconds) since 

   *          ns3::SystemWallClockMs::Start was invoked.

   *

   * It is possible to start a new measurement with ns3::SystemWallClockMs::Start

   * after this method returns.

   *

   * Returns int64_t to avoid dependency on clock_t in ns-3 code.

   */

  int64_t End (void);

  /**

   * \returns the measured elapsed wall clock time (in milliseconds) since 

   *          ns3::SystemWallClockMs::Start was invoked.

   *

   * Returns int64_t to avoid dependency on clock_t in ns-3 code.

   */

  int64_t GetElapsedReal (void) const;

  /**

   * \returns the measured elapsed 'user' wall clock time (in milliseconds) since 

   *          ns3::SystemWallClockMs::Start was invoked.

   *

   * Returns int64_t to avoid dependency on clock_t in ns-3 code.

   */

  int64_t GetElapsedUser (void) const;

  /**

   * \returns the measured elapsed 'system' wall clock time (in milliseconds) since 

   *          ns3::SystemWallClockMs::Start was invoked.

   *

   * Returns int64_t to avoid dependency on clock_t in ns-3 code.

   */

  int64_t GetElapsedSystem (void) const;

private:

  class SystemWallClockMsPrivate *m_priv;

};

} // namespace ns3

#endif /* SYSTEM_WALL_CLOCK_MS_H */