---

more/diag/stopwatch.h

Go to the documentation of this file.

//  Copyright (C) 2001  Petter Urkedal (petter.urkedal@matfys.lth.se)
//
//  This file 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 file 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
//
//  As a special exception, you may use this file as part of a free
//  software library without restriction.  Specifically, if other files
//  instantiate templates or use macros or inline functions from this
//  file, or you compile this file and link it with other files to
//  produce an executable, this file does not by itself cause the
//  resulting executable to be covered by the GNU General Public
//  License.  This exception does not however invalidate any other
//  reasons why the executable file might be covered by the GNU General
//  Public License.
//
//  $Id: stopwatch.h,v 1.1 2002/05/30 18:01:37 petter_urkedal Exp $


#include <stdexcept>
#include <more/sys/time.h>

namespace more {
namespace diag {

  //! Class for timing program execution.
  class stopwatch
  {
      bool run;
      mutable clock_t t0;
      mutable double accum;
    public:
      /** Construct a stopwatch initialized to t=0. */
      stopwatch()
          : run(false), accum(0) {}
      /** Construct a stopwatch initialized to the time \a t seconds. */
      stopwatch(double t)
          : run(false), accum(t) {}

      /** Start a stopwatch which is not already running.
          The stopwatch will continue from its current value. */
      void start()
      {
          if(run) throw std::logic_error
                      ("stopwatch::start(): Stopwatch is already running.");
          t0 = clock();
          run = true;
      }

      /** Stop a running stopwatch. */
      void stop()
      {
          if(!run) throw std::logic_error
                       ("stopwatch::stop(): Stopwatch is not running.");
          accum += double(clock()-t0)/CLOCKS_PER_SEC;
          run = false;
      }

      /** Reset the stopwatch.
          If the stopwatch is running, it will continue running from t=0. */
      void reset() { accum = 0; if (run) t0=clock(); }

      //! Start a stopwatch, which is not running, from t=0.
      void restart() { accum = 0; start(); }

      //! Conversion to double gives the current time in second.
      operator double() const { if (run) flush(); return accum; }

      //! Assign a time of \a t seconds to the stopwatch.
      stopwatch& operator=(double t) { t0=clock(); accum=t; return *this; }

      //! True iff the stopwatch is running.
      bool running() const { return run; }

      void flush() const
      {
          if (!run)
              throw std::logic_error("more::stopwatch::flush(): "
                                     "Stopwatch is not running.");
          clock_t t1 = clock();
          accum += double(t1-t0)/CLOCKS_PER_SEC;
          t0 = t1;
      }
  };

  inline std::ostream&
  operator<<(std::ostream& out, const stopwatch& sw)
  {
      sys::print_time_nicely(out, sw); return out;
  }

}}

---