COIN-OR::LEMON - Graph Library

source: lemon/lemon/time_measure.h @ 1298:a78e5b779b69

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1/* -*- mode: C++; indent-tabs-mode: nil; -*-
2 *
3 * This file is a part of LEMON, a generic C++ optimization library.
4 *
5 * Copyright (C) 2003-2013
6 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
7 * (Egervary Research Group on Combinatorial Optimization, EGRES).
8 *
9 * Permission to use, modify and distribute this software is granted
10 * provided that this copyright notice appears in all copies. For
11 * precise terms see the accompanying LICENSE file.
12 *
13 * This software is provided "AS IS" with no warranty of any kind,
14 * express or implied, and with no claim as to its suitability for any
15 * purpose.
16 *
17 */
18
19#ifndef LEMON_TIME_MEASURE_H
20#define LEMON_TIME_MEASURE_H
21
22///\ingroup timecount
23///\file
24///\brief Tools for measuring cpu usage
25
26#ifdef WIN32
27#include <lemon/bits/windows.h>
28#else
29#include <unistd.h>
30#include <sys/times.h>
31#include <sys/time.h>
32#endif
33
34#include <string>
35#include <fstream>
36#include <iostream>
37#include <lemon/math.h>
38
39namespace lemon {
40
41  /// \addtogroup timecount
42  /// @{
43
44  /// A class to store (cpu)time instances.
45
46  /// This class stores five time values.
47  /// - a real time
48  /// - a user cpu time
49  /// - a system cpu time
50  /// - a user cpu time of children
51  /// - a system cpu time of children
52  ///
53  /// TimeStamp's can be added to or substracted from each other and
54  /// they can be pushed to a stream.
55  ///
56  /// In most cases, perhaps the \ref Timer or the \ref TimeReport
57  /// class is what you want to use instead.
58
59  class TimeStamp
60  {
61    double utime;
62    double stime;
63    double cutime;
64    double cstime;
65    double rtime;
66
67  public:
68    ///Display format specifier
69
70    ///\e
71    ///
72    enum Format {
73      /// Reports all measured values
74      NORMAL = 0,
75      /// Only real time and an error indicator is displayed
76      SHORT = 1
77    };
78
79  private:
80    static Format _format;
81
82    void _reset() {
83      utime = stime = cutime = cstime = rtime = 0;
84    }
85
86  public:
87
88    ///Set output format
89
90    ///Set output format.
91    ///
92    ///The output format is global for all timestamp instances.
93    static void format(Format f) { _format = f; }
94    ///Retrieve the current output format
95
96    ///Retrieve the current output format
97    ///
98    ///The output format is global for all timestamp instances.
99    static Format format() { return _format; }
100
101
102    ///Read the current time values of the process
103    void stamp()
104    {
105#ifndef WIN32
106      timeval tv;
107      gettimeofday(&tv, 0);
108      rtime=tv.tv_sec+double(tv.tv_usec)/1e6;
109
110      tms ts;
111      double tck=sysconf(_SC_CLK_TCK);
112      times(&ts);
113      utime=ts.tms_utime/tck;
114      stime=ts.tms_stime/tck;
115      cutime=ts.tms_cutime/tck;
116      cstime=ts.tms_cstime/tck;
117#else
118      bits::getWinProcTimes(rtime, utime, stime, cutime, cstime);
119#endif
120    }
121
122    /// Constructor initializing with zero
123    TimeStamp()
124    { _reset(); }
125    ///Constructor initializing with the current time values of the process
126    TimeStamp(void *) { stamp();}
127
128    ///Set every time value to zero
129    TimeStamp &reset() {_reset();return *this;}
130
131    ///\e
132    TimeStamp &operator+=(const TimeStamp &b)
133    {
134      utime+=b.utime;
135      stime+=b.stime;
136      cutime+=b.cutime;
137      cstime+=b.cstime;
138      rtime+=b.rtime;
139      return *this;
140    }
141    ///\e
142    TimeStamp operator+(const TimeStamp &b) const
143    {
144      TimeStamp t(*this);
145      return t+=b;
146    }
147    ///\e
148    TimeStamp &operator-=(const TimeStamp &b)
149    {
150      utime-=b.utime;
151      stime-=b.stime;
152      cutime-=b.cutime;
153      cstime-=b.cstime;
154      rtime-=b.rtime;
155      return *this;
156    }
157    ///\e
158    TimeStamp operator-(const TimeStamp &b) const
159    {
160      TimeStamp t(*this);
161      return t-=b;
162    }
163    ///\e
164    TimeStamp &operator*=(double b)
165    {
166      utime*=b;
167      stime*=b;
168      cutime*=b;
169      cstime*=b;
170      rtime*=b;
171      return *this;
172    }
173    ///\e
174    TimeStamp operator*(double b) const
175    {
176      TimeStamp t(*this);
177      return t*=b;
178    }
179    friend TimeStamp operator*(double b,const TimeStamp &t);
180    ///\e
181    TimeStamp &operator/=(double b)
182    {
183      utime/=b;
184      stime/=b;
185      cutime/=b;
186      cstime/=b;
187      rtime/=b;
188      return *this;
189    }
190    ///\e
191    TimeStamp operator/(double b) const
192    {
193      TimeStamp t(*this);
194      return t/=b;
195    }
196    ///The time ellapsed since the last call of stamp()
197    TimeStamp ellapsed() const
198    {
199      TimeStamp t(NULL);
200      return t-*this;
201    }
202
203    friend std::ostream& operator<<(std::ostream& os,const TimeStamp &t);
204
205    ///Gives back the user time of the process
206    double userTime() const
207    {
208      return utime;
209    }
210    ///Gives back the system time of the process
211    double systemTime() const
212    {
213      return stime;
214    }
215    ///Gives back the user time of the process' children
216
217    ///\note On <tt>WIN32</tt> platform this value is not calculated.
218    ///
219    double cUserTime() const
220    {
221      return cutime;
222    }
223    ///Gives back the user time of the process' children
224
225    ///\note On <tt>WIN32</tt> platform this value is not calculated.
226    ///
227    double cSystemTime() const
228    {
229      return cstime;
230    }
231    ///Gives back the real time
232    double realTime() const {return rtime;}
233  };
234
235  inline TimeStamp operator*(double b,const TimeStamp &t)
236  {
237    return t*b;
238  }
239
240  ///Prints the time counters
241
242  ///Prints the time counters in the following form:
243  ///
244  /// <tt>u: XX.XXs s: XX.XXs cu: XX.XXs cs: XX.XXs real: XX.XXs</tt>
245  ///
246  /// where the values are the
247  /// \li \c u: user cpu time,
248  /// \li \c s: system cpu time,
249  /// \li \c cu: user cpu time of children,
250  /// \li \c cs: system cpu time of children,
251  /// \li \c real: real time.
252  /// \relates TimeStamp
253  /// \note On <tt>WIN32</tt> platform the cummulative values are not
254  /// calculated.
255  inline std::ostream& operator<<(std::ostream& os,const TimeStamp &t)
256  {
257    switch(t._format)
258      {
259      case TimeStamp::NORMAL:
260        os << "u: " << t.userTime() <<
261          "s, s: " << t.systemTime() <<
262          "s, cu: " << t.cUserTime() <<
263          "s, cs: " << t.cSystemTime() <<
264          "s, real: " << t.realTime() << "s";
265        break;
266      case TimeStamp::SHORT:
267        double total = t.userTime()+t.systemTime()+
268          t.cUserTime()+t.cSystemTime();
269        os << t.realTime()
270           << "s (err: " << round((t.realTime()-total)/
271                                  t.realTime()*10000)/100
272           << "%)";
273        break;
274      }
275    return os;
276  }
277
278  ///Class for measuring the cpu time and real time usage of the process
279
280  ///Class for measuring the cpu time and real time usage of the process.
281  ///It is quite easy-to-use, here is a short example.
282  ///\code
283  /// #include<lemon/time_measure.h>
284  /// #include<iostream>
285  ///
286  /// int main()
287  /// {
288  ///
289  ///   ...
290  ///
291  ///   Timer t;
292  ///   doSomething();
293  ///   std::cout << t << '\n';
294  ///   t.restart();
295  ///   doSomethingElse();
296  ///   std::cout << t << '\n';
297  ///
298  ///   ...
299  ///
300  /// }
301  ///\endcode
302  ///
303  ///The \ref Timer can also be \ref stop() "stopped" and
304  ///\ref start() "started" again, so it is possible to compute collected
305  ///running times.
306  ///
307  ///\warning Depending on the operation system and its actual configuration
308  ///the time counters have a certain (10ms on a typical Linux system)
309  ///granularity.
310  ///Therefore this tool is not appropriate to measure very short times.
311  ///Also, if you start and stop the timer very frequently, it could lead to
312  ///distorted results.
313  ///
314  ///\note If you want to measure the running time of the execution of a certain
315  ///function, consider the usage of \ref TimeReport instead.
316  ///
317  ///\sa TimeReport
318  class Timer
319  {
320    int _running; //Timer is running iff _running>0; (_running>=0 always holds)
321    TimeStamp start_time; //This is the relativ start-time if the timer
322                          //is _running, the collected _running time otherwise.
323
324    void _reset() {if(_running) start_time.stamp(); else start_time.reset();}
325
326  public:
327    ///Constructor.
328
329    ///\param run indicates whether or not the timer starts immediately.
330    ///
331    Timer(bool run=true) :_running(run) {_reset();}
332
333    ///\name Control the State of the Timer
334    ///Basically a Timer can be either running or stopped,
335    ///but it provides a bit finer control on the execution.
336    ///The \ref lemon::Timer "Timer" also counts the number of
337    ///\ref lemon::Timer::start() "start()" executions, and it stops
338    ///only after the same amount (or more) \ref lemon::Timer::stop()
339    ///"stop()"s. This can be useful e.g. to compute the running time
340    ///of recursive functions.
341
342    ///@{
343
344    ///Reset and stop the time counters
345
346    ///This function resets and stops the time counters
347    ///\sa restart()
348    void reset()
349    {
350      _running=0;
351      _reset();
352    }
353
354    ///Start the time counters
355
356    ///This function starts the time counters.
357    ///
358    ///If the timer is started more than ones, it will remain running
359    ///until the same amount of \ref stop() is called.
360    ///\sa stop()
361    void start()
362    {
363      if(_running) _running++;
364      else {
365        _running=1;
366        TimeStamp t;
367        t.stamp();
368        start_time=t-start_time;
369      }
370    }
371
372
373    ///Stop the time counters
374
375    ///This function stops the time counters. If start() was executed more than
376    ///once, then the same number of stop() execution is necessary the really
377    ///stop the timer.
378    ///
379    ///\sa halt()
380    ///\sa start()
381    ///\sa restart()
382    ///\sa reset()
383
384    void stop()
385    {
386      if(_running && !--_running) {
387        TimeStamp t;
388        t.stamp();
389        start_time=t-start_time;
390      }
391    }
392
393    ///Halt (i.e stop immediately) the time counters
394
395    ///This function stops immediately the time counters, i.e. <tt>t.halt()</tt>
396    ///is a faster
397    ///equivalent of the following.
398    ///\code
399    ///  while(t.running()) t.stop()
400    ///\endcode
401    ///
402    ///
403    ///\sa stop()
404    ///\sa restart()
405    ///\sa reset()
406
407    void halt()
408    {
409      if(_running) {
410        _running=0;
411        TimeStamp t;
412        t.stamp();
413        start_time=t-start_time;
414      }
415    }
416
417    ///Returns the running state of the timer
418
419    ///This function returns the number of stop() exections that is
420    ///necessary to really stop the timer.
421    ///For example, the timer
422    ///is running if and only if the return value is \c true
423    ///(i.e. greater than
424    ///zero).
425    int running()  { return _running; }
426
427
428    ///Restart the time counters
429
430    ///This function is a shorthand for
431    ///a reset() and a start() calls.
432    ///
433    void restart()
434    {
435      reset();
436      start();
437    }
438
439    ///@}
440
441    ///\name Query Functions for the Ellapsed Time
442
443    ///@{
444
445    ///Gives back the ellapsed user time of the process
446    double userTime() const
447    {
448      return operator TimeStamp().userTime();
449    }
450    ///Gives back the ellapsed system time of the process
451    double systemTime() const
452    {
453      return operator TimeStamp().systemTime();
454    }
455    ///Gives back the ellapsed user time of the process' children
456
457    ///\note On <tt>WIN32</tt> platform this value is not calculated.
458    ///
459    double cUserTime() const
460    {
461      return operator TimeStamp().cUserTime();
462    }
463    ///Gives back the ellapsed user time of the process' children
464
465    ///\note On <tt>WIN32</tt> platform this value is not calculated.
466    ///
467    double cSystemTime() const
468    {
469      return operator TimeStamp().cSystemTime();
470    }
471    ///Gives back the ellapsed real time
472    double realTime() const
473    {
474      return operator TimeStamp().realTime();
475    }
476    ///Computes the ellapsed time
477
478    ///This conversion computes the ellapsed time, therefore you can print
479    ///the ellapsed time like this.
480    ///\code
481    ///  Timer t;
482    ///  doSomething();
483    ///  std::cout << t << '\n';
484    ///\endcode
485    operator TimeStamp () const
486    {
487      TimeStamp t;
488      t.stamp();
489      return _running?t-start_time:start_time;
490    }
491
492
493    ///@}
494  };
495
496  ///Same as Timer but prints a report on destruction.
497
498  ///Same as \ref Timer but prints a report on destruction.
499  ///This example shows its usage.
500  ///\code
501  ///  void myAlg(ListGraph &g,int n)
502  ///  {
503  ///    TimeReport tr("Running time of myAlg: ");
504  ///    ... //Here comes the algorithm
505  ///  }
506  ///\endcode
507  ///
508  ///\sa Timer
509  ///\sa NoTimeReport
510  class TimeReport : public Timer
511  {
512    std::string _title;
513    std::ostream &_os;
514    bool _active;
515  public:
516    ///Constructor
517
518    ///Constructor.
519    ///\param title This text will be printed before the ellapsed time.
520    ///\param os The stream to print the report to.
521    ///\param run Sets whether the timer should start immediately.
522    ///\param active Sets whether the report should actually be printed
523    ///       on destruction.
524    TimeReport(std::string title,std::ostream &os=std::cerr,bool run=true,
525               bool active=true)
526      : Timer(run), _title(title), _os(os), _active(active) {}
527    ///Destructor that prints the ellapsed time
528    ~TimeReport()
529    {
530      if(_active) _os << _title << *this << std::endl;
531    }
532
533    ///Retrieve the activity status
534
535    ///\e
536    ///
537    bool active() const { return _active; }
538    ///Set the activity status
539
540    /// This function set whether the time report should actually be printed
541    /// on destruction.
542    void active(bool a) { _active=a; }
543  };
544
545  ///'Do nothing' version of TimeReport
546
547  ///\sa TimeReport
548  ///
549  class NoTimeReport
550  {
551  public:
552    ///\e
553    NoTimeReport(std::string,std::ostream &,bool) {}
554    ///\e
555    NoTimeReport(std::string,std::ostream &) {}
556    ///\e
557    NoTimeReport(std::string) {}
558    ///\e Do nothing.
559    ~NoTimeReport() {}
560
561    operator TimeStamp () const { return TimeStamp(); }
562    void reset() {}
563    void start() {}
564    void stop() {}
565    void halt() {}
566    int running() { return 0; }
567    void restart() {}
568    double userTime() const { return 0; }
569    double systemTime() const { return 0; }
570    double cUserTime() const { return 0; }
571    double cSystemTime() const { return 0; }
572    double realTime() const { return 0; }
573  };
574
575  ///Tool to measure the running time more exactly.
576
577  ///This function calls \c f several times and returns the average
578  ///running time. The number of the executions will be choosen in such a way
579  ///that the full real running time will be roughly between \c min_time
580  ///and <tt>2*min_time</tt>.
581  ///\param f the function object to be measured.
582  ///\param min_time the minimum total running time.
583  ///\retval num if it is not \c NULL, then the actual
584  ///        number of execution of \c f will be written into <tt>*num</tt>.
585  ///\retval full_time if it is not \c NULL, then the actual
586  ///        total running time will be written into <tt>*full_time</tt>.
587  ///\return The average running time of \c f.
588
589  template<class F>
590  TimeStamp runningTimeTest(F f,double min_time=10,unsigned int *num = NULL,
591                            TimeStamp *full_time=NULL)
592  {
593    TimeStamp full;
594    unsigned int total=0;
595    Timer t;
596    for(unsigned int tn=1;tn <= 1U<<31 && full.realTime()<=min_time; tn*=2) {
597      for(;total<tn;total++) f();
598      full=t;
599    }
600    if(num) *num=total;
601    if(full_time) *full_time=full;
602    return full/total;
603  }
604
605  /// @}
606
607
608} //namespace lemon
609
610#endif //LEMON_TIME_MEASURE_H
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