lemon/time_measure.h
author Alpar Juttner <alpar@cs.elte.hu>
Thu, 05 Mar 2009 06:51:53 +0000
changeset 528 097d7c4634ea
parent 511 879c55700cd4
child 595 94387da47f79
child 1078 c59bdcc8e33e
permissions -rw-r--r--
Fix missing 'inline' specifier in time_measure.h (#239)
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/* -*- mode: C++; indent-tabs-mode: nil; -*-
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 *
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 * This file is a part of LEMON, a generic C++ optimization library.
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 *
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 * Copyright (C) 2003-2008
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 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
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 * (Egervary Research Group on Combinatorial Optimization, EGRES).
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 *
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 * Permission to use, modify and distribute this software is granted
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 * provided that this copyright notice appears in all copies. For
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 * precise terms see the accompanying LICENSE file.
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 *
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 * This software is provided "AS IS" with no warranty of any kind,
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 * express or implied, and with no claim as to its suitability for any
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 * purpose.
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 *
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 */
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#ifndef LEMON_TIME_MEASURE_H
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#define LEMON_TIME_MEASURE_H
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///\ingroup timecount
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///\file
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///\brief Tools for measuring cpu usage
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#ifdef WIN32
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#include <lemon/bits/windows.h>
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#else
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#include <unistd.h>
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#include <sys/times.h>
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#include <sys/time.h>
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#endif
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#include <string>
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#include <fstream>
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#include <iostream>
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namespace lemon {
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  /// \addtogroup timecount
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  /// @{
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  /// A class to store (cpu)time instances.
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  /// This class stores five time values.
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  /// - a real time
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  /// - a user cpu time
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  /// - a system cpu time
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  /// - a user cpu time of children
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  /// - a system cpu time of children
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  ///
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  /// TimeStamp's can be added to or substracted from each other and
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  /// they can be pushed to a stream.
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  ///
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  /// In most cases, perhaps the \ref Timer or the \ref TimeReport
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  /// class is what you want to use instead.
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  class TimeStamp
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  {
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    double utime;
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    double stime;
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    double cutime;
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    double cstime;
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    double rtime;
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    void _reset() {
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      utime = stime = cutime = cstime = rtime = 0;
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    }
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  public:
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    ///Read the current time values of the process
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    void stamp()
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    {
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#ifndef WIN32
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      timeval tv;
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      gettimeofday(&tv, 0);
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      rtime=tv.tv_sec+double(tv.tv_usec)/1e6;
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      tms ts;
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      double tck=sysconf(_SC_CLK_TCK);
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      times(&ts);
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      utime=ts.tms_utime/tck;
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      stime=ts.tms_stime/tck;
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      cutime=ts.tms_cutime/tck;
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      cstime=ts.tms_cstime/tck;
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#else
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      bits::getWinProcTimes(rtime, utime, stime, cutime, cstime);
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#endif
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    }
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    /// Constructor initializing with zero
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    TimeStamp()
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    { _reset(); }
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    ///Constructor initializing with the current time values of the process
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    TimeStamp(void *) { stamp();}
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    ///Set every time value to zero
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    TimeStamp &reset() {_reset();return *this;}
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    ///\e
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    TimeStamp &operator+=(const TimeStamp &b)
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    {
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      utime+=b.utime;
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      stime+=b.stime;
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      cutime+=b.cutime;
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      cstime+=b.cstime;
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      rtime+=b.rtime;
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      return *this;
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    }
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    ///\e
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    TimeStamp operator+(const TimeStamp &b) const
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    {
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      TimeStamp t(*this);
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      return t+=b;
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    }
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    ///\e
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    TimeStamp &operator-=(const TimeStamp &b)
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    {
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      utime-=b.utime;
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      stime-=b.stime;
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      cutime-=b.cutime;
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      cstime-=b.cstime;
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      rtime-=b.rtime;
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      return *this;
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    }
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    ///\e
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    TimeStamp operator-(const TimeStamp &b) const
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    {
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      TimeStamp t(*this);
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      return t-=b;
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    }
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    ///\e
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    TimeStamp &operator*=(double b)
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    {
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      utime*=b;
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      stime*=b;
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      cutime*=b;
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      cstime*=b;
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      rtime*=b;
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      return *this;
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    }
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    ///\e
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    TimeStamp operator*(double b) const
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    {
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      TimeStamp t(*this);
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      return t*=b;
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    }
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    friend TimeStamp operator*(double b,const TimeStamp &t);
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    ///\e
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    TimeStamp &operator/=(double b)
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    {
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      utime/=b;
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      stime/=b;
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      cutime/=b;
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      cstime/=b;
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      rtime/=b;
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      return *this;
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    }
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    ///\e
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    TimeStamp operator/(double b) const
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    {
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      TimeStamp t(*this);
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      return t/=b;
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    }
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    ///The time ellapsed since the last call of stamp()
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    TimeStamp ellapsed() const
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    {
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      TimeStamp t(NULL);
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      return t-*this;
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    }
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    friend std::ostream& operator<<(std::ostream& os,const TimeStamp &t);
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    ///Gives back the user time of the process
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    double userTime() const
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    {
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      return utime;
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    }
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    ///Gives back the system time of the process
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    double systemTime() const
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    {
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      return stime;
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    }
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    ///Gives back the user time of the process' children
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    ///\note On <tt>WIN32</tt> platform this value is not calculated.
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    ///
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    double cUserTime() const
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    {
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      return cutime;
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    }
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    ///Gives back the user time of the process' children
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    ///\note On <tt>WIN32</tt> platform this value is not calculated.
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    ///
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    double cSystemTime() const
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    {
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      return cstime;
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    }
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    ///Gives back the real time
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    double realTime() const {return rtime;}
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  };
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  inline TimeStamp operator*(double b,const TimeStamp &t)
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  {
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    return t*b;
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  }
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  ///Prints the time counters
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  ///Prints the time counters in the following form:
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  ///
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  /// <tt>u: XX.XXs s: XX.XXs cu: XX.XXs cs: XX.XXs real: XX.XXs</tt>
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  ///
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  /// where the values are the
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  /// \li \c u: user cpu time,
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  /// \li \c s: system cpu time,
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  /// \li \c cu: user cpu time of children,
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  /// \li \c cs: system cpu time of children,
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  /// \li \c real: real time.
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  /// \relates TimeStamp
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  /// \note On <tt>WIN32</tt> platform the cummulative values are not
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  /// calculated.
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  inline std::ostream& operator<<(std::ostream& os,const TimeStamp &t)
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  {
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    os << "u: " << t.userTime() <<
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      "s, s: " << t.systemTime() <<
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      "s, cu: " << t.cUserTime() <<
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      "s, cs: " << t.cSystemTime() <<
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      "s, real: " << t.realTime() << "s";
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    return os;
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  }
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  ///Class for measuring the cpu time and real time usage of the process
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  ///Class for measuring the cpu time and real time usage of the process.
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  ///It is quite easy-to-use, here is a short example.
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  ///\code
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  /// #include<lemon/time_measure.h>
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  /// #include<iostream>
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  ///
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  /// int main()
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  /// {
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  ///
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  ///   ...
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  ///
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  ///   Timer t;
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  ///   doSomething();
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  ///   std::cout << t << '\n';
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  ///   t.restart();
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  ///   doSomethingElse();
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  ///   std::cout << t << '\n';
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  ///
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  ///   ...
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  ///
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  /// }
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  ///\endcode
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  ///
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  ///The \ref Timer can also be \ref stop() "stopped" and
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  ///\ref start() "started" again, so it is possible to compute collected
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  ///running times.
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  ///
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  ///\warning Depending on the operation system and its actual configuration
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  ///the time counters have a certain (10ms on a typical Linux system)
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  ///granularity.
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  ///Therefore this tool is not appropriate to measure very short times.
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  ///Also, if you start and stop the timer very frequently, it could lead to
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  ///distorted results.
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  ///
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  ///\note If you want to measure the running time of the execution of a certain
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  ///function, consider the usage of \ref TimeReport instead.
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  ///
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  ///\sa TimeReport
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  class Timer
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  {
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    int _running; //Timer is running iff _running>0; (_running>=0 always holds)
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    TimeStamp start_time; //This is the relativ start-time if the timer
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                          //is _running, the collected _running time otherwise.
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    void _reset() {if(_running) start_time.stamp(); else start_time.reset();}
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  public:
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    ///Constructor.
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    ///\param run indicates whether or not the timer starts immediately.
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    ///
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    Timer(bool run=true) :_running(run) {_reset();}
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    ///\name Control the state of the timer
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    ///Basically a Timer can be either running or stopped,
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    ///but it provides a bit finer control on the execution.
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    ///The \ref lemon::Timer "Timer" also counts the number of
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    ///\ref lemon::Timer::start() "start()" executions, and it stops
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    ///only after the same amount (or more) \ref lemon::Timer::stop()
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    ///"stop()"s. This can be useful e.g. to compute the running time
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    ///of recursive functions.
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    ///@{
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    ///Reset and stop the time counters
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    ///This function resets and stops the time counters
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    ///\sa restart()
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    void reset()
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    {
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      _running=0;
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      _reset();
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    }
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    ///Start the time counters
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    ///This function starts the time counters.
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    ///
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    ///If the timer is started more than ones, it will remain running
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    ///until the same amount of \ref stop() is called.
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    ///\sa stop()
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    void start()
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    {
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      if(_running) _running++;
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      else {
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        _running=1;
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        TimeStamp t;
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        t.stamp();
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        start_time=t-start_time;
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      }
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    }
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    ///Stop the time counters
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    ///This function stops the time counters. If start() was executed more than
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    ///once, then the same number of stop() execution is necessary the really
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    ///stop the timer.
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    ///
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    ///\sa halt()
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    ///\sa start()
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    ///\sa restart()
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    ///\sa reset()
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    void stop()
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    {
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      if(_running && !--_running) {
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        TimeStamp t;
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        t.stamp();
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        start_time=t-start_time;
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      }
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    }
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    ///Halt (i.e stop immediately) the time counters
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    ///This function stops immediately the time counters, i.e. <tt>t.halt()</tt>
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    ///is a faster
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    ///equivalent of the following.
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    ///\code
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    ///  while(t.running()) t.stop()
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    ///\endcode
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    ///
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    ///
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    ///\sa stop()
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    ///\sa restart()
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    ///\sa reset()
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    void halt()
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    {
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      if(_running) {
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        _running=0;
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        TimeStamp t;
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        t.stamp();
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        start_time=t-start_time;
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      }
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    }
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    ///Returns the running state of the timer
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    ///This function returns the number of stop() exections that is
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    ///necessary to really stop the timer.
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    ///For example the timer
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    ///is running if and only if the return value is \c true
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    ///(i.e. greater than
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    ///zero).
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    int running()  { return _running; }
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    ///Restart the time counters
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    ///This function is a shorthand for
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    ///a reset() and a start() calls.
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    ///
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    void restart()
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    {
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      reset();
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      start();
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    }
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    ///@}
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    ///\name Query Functions for the ellapsed time
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    ///@{
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    ///Gives back the ellapsed user time of the process
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    double userTime() const
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    {
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      return operator TimeStamp().userTime();
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    }
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    ///Gives back the ellapsed system time of the process
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    double systemTime() const
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    {
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      return operator TimeStamp().systemTime();
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    }
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    ///Gives back the ellapsed user time of the process' children
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    ///\note On <tt>WIN32</tt> platform this value is not calculated.
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    ///
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    double cUserTime() const
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    {
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      return operator TimeStamp().cUserTime();
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    }
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    ///Gives back the ellapsed user time of the process' children
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    ///\note On <tt>WIN32</tt> platform this value is not calculated.
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    ///
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    double cSystemTime() const
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    {
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      return operator TimeStamp().cSystemTime();
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    }
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    ///Gives back the ellapsed real time
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    double realTime() const
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    {
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      return operator TimeStamp().realTime();
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    }
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    ///Computes the ellapsed time
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    ///This conversion computes the ellapsed time, therefore you can print
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   436
    ///the ellapsed time like this.
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    ///\code
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    ///  Timer t;
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   439
    ///  doSomething();
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    ///  std::cout << t << '\n';
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    ///\endcode
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   442
    operator TimeStamp () const
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   443
    {
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      TimeStamp t;
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      t.stamp();
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   446
      return _running?t-start_time:start_time;
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    }
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   448
alpar@119
   449
alpar@119
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    ///@}
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  };
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   453
  ///Same as Timer but prints a report on destruction.
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   454
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  ///Same as \ref Timer but prints a report on destruction.
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   456
  ///This example shows its usage.
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   457
  ///\code
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   458
  ///  void myAlg(ListGraph &g,int n)
alpar@119
   459
  ///  {
alpar@119
   460
  ///    TimeReport tr("Running time of myAlg: ");
alpar@119
   461
  ///    ... //Here comes the algorithm
alpar@119
   462
  ///  }
alpar@119
   463
  ///\endcode
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  ///
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   465
  ///\sa Timer
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   466
  ///\sa NoTimeReport
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  class TimeReport : public Timer
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   468
  {
alpar@119
   469
    std::string _title;
alpar@119
   470
    std::ostream &_os;
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   471
  public:
kpeter@313
   472
    ///Constructor
alpar@119
   473
kpeter@313
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    ///Constructor.
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    ///\param title This text will be printed before the ellapsed time.
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   476
    ///\param os The stream to print the report to.
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   477
    ///\param run Sets whether the timer should start immediately.
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   478
    TimeReport(std::string title,std::ostream &os=std::cerr,bool run=true)
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      : Timer(run), _title(title), _os(os){}
kpeter@313
   480
    ///Destructor that prints the ellapsed time
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   481
    ~TimeReport()
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   482
    {
alpar@119
   483
      _os << _title << *this << std::endl;
alpar@119
   484
    }
alpar@119
   485
  };
alpar@209
   486
kpeter@313
   487
  ///'Do nothing' version of TimeReport
alpar@119
   488
alpar@119
   489
  ///\sa TimeReport
alpar@119
   490
  ///
alpar@119
   491
  class NoTimeReport
alpar@119
   492
  {
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   493
  public:
alpar@119
   494
    ///\e
alpar@119
   495
    NoTimeReport(std::string,std::ostream &,bool) {}
alpar@119
   496
    ///\e
alpar@119
   497
    NoTimeReport(std::string,std::ostream &) {}
alpar@119
   498
    ///\e
alpar@119
   499
    NoTimeReport(std::string) {}
alpar@119
   500
    ///\e Do nothing.
alpar@119
   501
    ~NoTimeReport() {}
alpar@119
   502
alpar@119
   503
    operator TimeStamp () const { return TimeStamp(); }
alpar@119
   504
    void reset() {}
alpar@119
   505
    void start() {}
alpar@119
   506
    void stop() {}
alpar@209
   507
    void halt() {}
alpar@119
   508
    int running() { return 0; }
alpar@119
   509
    void restart() {}
alpar@119
   510
    double userTime() const { return 0; }
alpar@119
   511
    double systemTime() const { return 0; }
alpar@119
   512
    double cUserTime() const { return 0; }
alpar@119
   513
    double cSystemTime() const { return 0; }
alpar@119
   514
    double realTime() const { return 0; }
alpar@119
   515
  };
alpar@209
   516
alpar@119
   517
  ///Tool to measure the running time more exactly.
alpar@209
   518
alpar@119
   519
  ///This function calls \c f several times and returns the average
alpar@119
   520
  ///running time. The number of the executions will be choosen in such a way
alpar@119
   521
  ///that the full real running time will be roughly between \c min_time
alpar@119
   522
  ///and <tt>2*min_time</tt>.
alpar@119
   523
  ///\param f the function object to be measured.
alpar@119
   524
  ///\param min_time the minimum total running time.
alpar@119
   525
  ///\retval num if it is not \c NULL, then the actual
alpar@119
   526
  ///        number of execution of \c f will be written into <tt>*num</tt>.
alpar@119
   527
  ///\retval full_time if it is not \c NULL, then the actual
alpar@119
   528
  ///        total running time will be written into <tt>*full_time</tt>.
alpar@119
   529
  ///\return The average running time of \c f.
alpar@209
   530
alpar@119
   531
  template<class F>
alpar@119
   532
  TimeStamp runningTimeTest(F f,double min_time=10,unsigned int *num = NULL,
alpar@119
   533
                            TimeStamp *full_time=NULL)
alpar@119
   534
  {
alpar@119
   535
    TimeStamp full;
alpar@119
   536
    unsigned int total=0;
alpar@119
   537
    Timer t;
alpar@119
   538
    for(unsigned int tn=1;tn <= 1U<<31 && full.realTime()<=min_time; tn*=2) {
alpar@119
   539
      for(;total<tn;total++) f();
alpar@119
   540
      full=t;
alpar@119
   541
    }
alpar@119
   542
    if(num) *num=total;
alpar@119
   543
    if(full_time) *full_time=full;
alpar@119
   544
    return full/total;
alpar@119
   545
  }
alpar@209
   546
alpar@209
   547
  /// @}
alpar@119
   548
alpar@119
   549
alpar@119
   550
} //namespace lemon
alpar@119
   551
alpar@119
   552
#endif //LEMON_TIME_MEASURE_H