/*
 * Copyright (c) 1996 Gunther Schadow.  All rights reserved.
 *
 * 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 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#ifndef CXX_TIMER_H
#define CXX_TIMER_H

#pragma interface

#include <sys/types.h>
#include <sys/time.h>
#include <unistd.h>

// Just a C++ wrapper to attach a few calculus operators to
// struct timeval
class Timeval: public timeval
{
 public:
  Timeval() { tv_sec  = 0; tv_usec = 0; }
  Timeval(const timeval &x) { tv_sec=x.tv_sec; tv_usec=x.tv_usec; }
  Timeval(u_int sec, u_int usec = 0);
  const Timeval &operator += (const Timeval &x);
  const Timeval &operator -= (const Timeval &x);
  const Timeval &operator *= (u_int x);
  static const Timeval null;
};

// NOTE: the class Timer should currently not be instantiated
// on the heap since this may lead to restoring the wrong timer
// on delete.

class Timer
{
 public:
  typedef void (*alrmhdl_t)(Timer&);

  Timer(u_int vsec, u_int vusec = 0, u_int isec = 0, u_int iusec = 0,
	alrmhdl_t hdl = NULL);
  ~Timer();
  
  void get(u_int *vsec, u_int *vusec = NULL,
	   u_int *isec = NULL, u_int *iusec = NULL) const;
  
  int  expired() { return _alrm_cnt; }

  static void sleep(u_int vsec, u_int vusec = 0);
  
 private:
  u_long           _alrm_cnt;
  itimerval        _val;
  itimerval        _orig_val;  
  Timeval          _init_val;
  alrmhdl_t        _handler;
  class Timer     *_orig_timer;

  static class Signal  _sigalrm;
  static class Timer  *_active_timer;
  static int alrmsuperhandler(class Signal&);

 private:
  Timer(const Timer &);
  const Timer &operator=(const Timer &);
};

#endif