/* Pending_Element class declaration.
   Copyright (C) 2002-2004 Roberto Bagnara <bagnara@cs.unipr.it>

This file is part of the Parma Watchdog Library (PWL).

The PWL 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.

The PWL 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.

For the most up-to-date information see
http://www.cs.unipr.it/Software/ . */

#ifndef PWL_Pending_Element_defs_hh
#define PWL_Pending_Element_defs_hh 1

#include "Pending_Element.types.hh"
#include "Doubly_Linked_Object.defs.hh"
#include "Time.defs.hh"
#include "Handler.types.hh"

//! A class for pending watchdog events with embedded links.
/*!
  Each pending watchdog event is characterized by a deadline (a positive
  time interval), an associated handler that will be invoked upon event
  expiration, and a boolean flag that indicates whether the event has already
  expired or not.
*/
class Parma_Watchdog_Library::Pending_Element : public Doubly_Linked_Object {
public:
  //! Constructs an element with the given attributes.
  Pending_Element(const Time& deadline,
		  const Handler& handler,
		  bool& expired_flag);

  //! Modifies \p *this so that it has the given attributes.
  void assign(const Time& deadline,
	      const Handler& handler,
	      bool& expired_flag);

  //! Returns the deadline of the event.
  const Time& deadline() const;

  //! Returns the handler associated to the event.
  const Handler& handler() const;

  //! Returns a reference to the "event-expired" flag.
  bool& expired_flag() const;

  //! Checks if all the invariants are satisfied.
  bool OK() const;

private:
  //! The deadline of the event.
  Time d;

  //! A pointer to the handler associated to the event.
  const Handler* p_h;

  //! A pointer to a flag saying whether the event has already expired or not.
  bool* p_f;
};

#include "Pending_Element.inlines.hh"

#endif // !defined(PWL_Pending_Element_defs_hh)