COIN-OR::LEMON - Graph Library

source: lemon-0.x/lemon/time_measure.h @ 1855:c72636dcf0bd

Last change on this file since 1855:c72636dcf0bd was 1855:c72636dcf0bd, checked in by Alpar Juttner, 14 years ago

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1/* -*- C++ -*-
2 * lemon/time_measure.h - Part of LEMON, a generic C++ optimization library
3 *
4 * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
5 * (Egervary Research Group on Combinatorial Optimization, EGRES).
6 *
7 * Permission to use, modify and distribute this software is granted
8 * provided that this copyright notice appears in all copies. For
9 * precise terms see the accompanying LICENSE file.
10 *
11 * This software is provided "AS IS" with no warranty of any kind,
12 * express or implied, and with no claim as to its suitability for any
13 * purpose.
14 *
15 */
16
17#ifndef LEMON_TIME_MEASURE_H
18#define LEMON_TIME_MEASURE_H
19
20///\ingroup timecount
21///\file
22///\brief Tools for measuring cpu usage
23
24#include <sys/time.h>
25#include <sys/times.h>
26#include <fstream>
27#include <iostream>
28#include <unistd.h>
29
30namespace lemon {
31
32  /// \addtogroup timecount
33  /// @{
34
35  /// A class to store (cpu)time instances.
36
37  /// This class stores five time values.
38  /// - a real time
39  /// - a user cpu time
40  /// - a system cpu time
41  /// - a user cpu time of children
42  /// - a system cpu time of children
43  ///
44  /// TimeStamp's can be added to or substracted from each other and
45  /// they can be pushed to a stream.
46  ///
47  /// In most cases, perhaps the \ref Timer or the \ref TimeReport
48  /// class is what you want to use instead.
49  ///
50  ///\author Alpar Juttner
51
52  class TimeStamp
53  {
54    struct rtms
55    {
56      double tms_utime;
57      double tms_stime;
58      double tms_cutime;
59      double tms_cstime;
60      rtms() {}
61      rtms(tms ts) : tms_utime(ts.tms_utime), tms_stime(ts.tms_stime),
62                     tms_cutime(ts.tms_cutime), tms_cstime(ts.tms_cstime) {}
63    };
64    rtms ts;
65    double real_time;
66 
67    rtms &getTms() {return ts;}
68    const rtms &getTms() const {return ts;}
69
70    void _reset()
71    { ts.tms_utime=ts.tms_stime=ts.tms_cutime=ts.tms_cstime=0; real_time=0;}
72
73  public:
74
75    ///Read the current time values of the process
76    void stamp()
77    {
78      timeval tv;
79      tms _ts;
80      times(&_ts);
81      gettimeofday(&tv, 0);real_time=tv.tv_sec+double(tv.tv_usec)/1e6;
82      ts=_ts;
83    }
84 
85    /// Constructor initializing with zero
86    TimeStamp()
87    { _reset(); }
88    ///Constructor initializing with the current time values of the process
89    TimeStamp(void *) { stamp();}
90 
91    ///Set every time value to zero
92    TimeStamp &reset() {_reset();return *this;}
93
94    ///\e
95    TimeStamp &operator+=(const TimeStamp &b)
96    {
97      ts.tms_utime+=b.ts.tms_utime;
98      ts.tms_stime+=b.ts.tms_stime;
99      ts.tms_cutime+=b.ts.tms_cutime;
100      ts.tms_cstime+=b.ts.tms_cstime;
101      real_time+=b.real_time;
102      return *this;
103    }
104    ///\e
105    TimeStamp operator+(const TimeStamp &b) const
106    {
107      TimeStamp t(*this);
108      return t+=b;
109    }
110    ///\e
111    TimeStamp &operator-=(const TimeStamp &b)
112    {
113      ts.tms_utime-=b.ts.tms_utime;
114      ts.tms_stime-=b.ts.tms_stime;
115      ts.tms_cutime-=b.ts.tms_cutime;
116      ts.tms_cstime-=b.ts.tms_cstime;
117      real_time-=b.real_time;
118      return *this;
119    }
120    ///\e
121    TimeStamp operator-(const TimeStamp &b) const
122    {
123      TimeStamp t(*this);
124      return t-=b;
125    }
126    ///\e
127    TimeStamp &operator*=(double b)
128    {
129      ts.tms_utime*=b;
130      ts.tms_stime*=b;
131      ts.tms_cutime*=b;
132      ts.tms_cstime*=b;
133      real_time*=b;
134      return *this;
135    }
136    ///\e
137    TimeStamp operator*(double b) const
138    {
139      TimeStamp t(*this);
140      return t*=b;
141    }
142    friend TimeStamp operator*(double b,const TimeStamp &t);
143    ///\e
144    TimeStamp &operator/=(double b)
145    {
146      ts.tms_utime/=b;
147      ts.tms_stime/=b;
148      ts.tms_cutime/=b;
149      ts.tms_cstime/=b;
150      real_time/=b;
151      return *this;
152    }
153    ///\e
154    TimeStamp operator/(double b) const
155    {
156      TimeStamp t(*this);
157      return t/=b;
158    }
159    ///The time ellapsed since the last call of stamp()
160    TimeStamp ellapsed() const
161    {
162      TimeStamp t(NULL);
163      return t-*this;
164    }
165 
166    friend std::ostream& operator<<(std::ostream& os,const TimeStamp &t);
167 
168    ///Gives back the user time of the process
169    double userTime() const
170    {
171      return double(ts.tms_utime)/sysconf(_SC_CLK_TCK);
172    }
173    ///Gives back the system time of the process
174    double systemTime() const
175    {
176      return double(ts.tms_stime)/sysconf(_SC_CLK_TCK);
177    }
178    ///Gives back the user time of the process' children
179    double cUserTime() const
180    {
181      return double(ts.tms_cutime)/sysconf(_SC_CLK_TCK);
182    }
183    ///Gives back the user time of the process' children
184    double cSystemTime() const
185    {
186      return double(ts.tms_cstime)/sysconf(_SC_CLK_TCK);
187    }
188    ///Gives back the real time
189    double realTime() const {return real_time;}
190  };
191
192  TimeStamp operator*(double b,const TimeStamp &t)
193  {
194    return t*b;
195  }
196 
197  ///Prints the time counters
198
199  ///Prints the time counters in the following form:
200  ///
201  /// <tt>u: XX.XXs s: XX.XXs cu: XX.XXs cs: XX.XXs real: XX.XXs</tt>
202  ///
203  /// where the values are the
204  /// \li \c u: user cpu time,
205  /// \li \c s: system cpu time,
206  /// \li \c cu: user cpu time of children,
207  /// \li \c cs: system cpu time of children,
208  /// \li \c real: real time.
209  /// \relates TimeStamp
210  inline std::ostream& operator<<(std::ostream& os,const TimeStamp &t)
211  {
212    long cls = sysconf(_SC_CLK_TCK);
213    os << "u: " << double(t.getTms().tms_utime)/cls <<
214      "s, s: " << double(t.getTms().tms_stime)/cls <<
215      "s, cu: " << double(t.getTms().tms_cutime)/cls <<
216      "s, cs: " << double(t.getTms().tms_cstime)/cls <<
217      "s, real: " << t.realTime() << "s";
218    return os;
219  }
220
221  ///Class for measuring the cpu time and real time usage of the process
222
223  ///Class for measuring the cpu time and real time usage of the process.
224  ///It is quite easy-to-use, here is a short example.
225  ///\code
226  ///#include<lemon/time_measure.h>
227  ///#include<iostream>
228  ///
229  ///int main()
230  ///{
231  ///
232  ///  ...
233  ///
234  ///  Timer T;
235  ///  doSomething();
236  ///  std::cout << T << '\n';
237  ///  T.restart();
238  ///  doSomethingElse();
239  ///  std::cout << T << '\n';
240  ///
241  ///  ...
242  ///
243  ///}
244  ///\endcode
245  ///
246  ///The \ref Timer can also be \ref stop() "stopped" and
247  ///\ref start() "started" again, so it is possible to compute collected
248  ///running times.
249  ///
250  ///\warning Depending on the operation system and its actual configuration
251  ///the time counters have a certain (10ms on a typical Linux system)
252  ///granularity.
253  ///Therefore this tool is not appropriate to measure very short times.
254  ///Also, if you start and stop the timer very frequently, it could lead
255  ///distorted results.
256  ///
257  ///\note If you want to measure the running time of the execution of a certain
258  ///function, consider the usage of \ref TimeReport instead.
259  ///
260  ///\todo This shouldn't be Unix (Linux) specific.
261  ///\sa TimeReport
262  ///
263  ///\author Alpar Juttner
264  class Timer
265  {
266    int _running; //Timer is running iff _running>0; (_running>=0 always holds)
267    TimeStamp start_time; //This is the relativ start-time if the timer
268                          //is _running, the collected _running time otherwise.
269   
270    void _reset() {if(_running) start_time.stamp(); else start_time.reset();}
271 
272  public:
273    ///Constructor.
274
275    ///\param _running indicates whether or not the timer starts immediately.
276    ///
277    Timer(bool run=true) :_running(run) {_reset();}
278
279    ///\name Control the state of the timer
280    ///Basically a Timer can be either running or stopped,
281    ///but it provides a bit finer control on the execution.
282    ///The \ref Timer also counts the number of \ref start()
283    ///executions, and is stops only after the same amount (or more)
284    ///\ref stop() "stop()"s. This can be useful e.g. to compute the running time
285    ///of recursive functions.
286    ///
287
288    ///@{
289
290    ///Reset and stop the time counters
291
292    ///This function resets and stops the time counters
293    ///\sa restart()
294    void reset()
295    {
296      _running=0;
297      _reset();
298    }
299
300    ///Start the time counters
301   
302    ///This function starts the time counters.
303    ///
304    ///If the timer is started more than ones, it will remain running
305    ///until the same amount of \ref stop() is called.
306    ///\sa stop()
307    void start()
308    {
309      if(_running) _running++;
310      else {
311        _running=1;
312        TimeStamp t;
313        t.stamp();
314        start_time=t-start_time;
315      }
316    }
317
318   
319    ///Stop the time counters
320
321    ///This function stops the time counters. If start() was executed more than
322    ///once, then the same number of stop() execution is necessary the really
323    ///stop the timer.
324    ///
325    ///\sa halt()
326    ///\sa start()
327    ///\sa restart()
328    ///\sa reset()
329
330    void stop()
331    {
332      if(_running && !--_running) {
333        TimeStamp t;
334        t.stamp();
335        start_time=t-start_time;
336      }
337    }
338
339    ///Halt (i.e stop immediately) the time counters
340
341    ///This function stops immediately the time counters.
342    ///
343    ///\sa stop()
344    ///\sa restart()
345    ///\sa reset()
346
347    void halt()
348    {
349      if(_running) {
350        _running=0;
351        TimeStamp t;
352        t.stamp();
353        start_time=t-start_time;
354      }
355    }
356
357    ///Returns the running state of the timer
358
359    ///This function returns the number of stop() exections that is
360    ///necessary to really stop the timer.
361    ///For example the timer
362    ///is running if and only if the return value is \c true
363    ///(i.e. greater than
364    ///zero).
365    int running()  { return _running; }
366   
367   
368    ///Restart the time counters
369
370    ///This function is a shorthand for
371    ///a reset() and a start() calls.
372    ///
373    void restart()
374    {
375      reset();
376      start();
377    }
378   
379    ///@}
380
381    ///\name Query Functions for the ellapsed time
382
383    ///@{
384
385    ///Gives back the ellapsed user time of the process
386    double userTime() const
387    {
388      return operator TimeStamp().userTime();
389    }
390    ///Gives back the ellapsed system time of the process
391    double systemTime() const
392    {
393      return operator TimeStamp().systemTime();
394    }
395    ///Gives back the ellapsed user time of the process' children
396    double cUserTime() const
397    {
398      return operator TimeStamp().cUserTime();
399    }
400    ///Gives back the ellapsed user time of the process' children
401    double cSystemTime() const
402    {
403      return operator TimeStamp().cSystemTime();
404    }
405    ///Gives back the ellapsed real time
406    double realTime() const
407    {
408      return operator TimeStamp().realTime();
409    }
410    ///Computes the ellapsed time
411
412    ///This conversion computes the ellapsed time, therefore you can print
413    ///the ellapsed time like this.
414    ///\code
415    ///  Timer T;
416    ///  doSomething();
417    ///  std::cout << T << '\n';
418    ///\endcode
419    operator TimeStamp () const
420    {
421      TimeStamp t;
422      t.stamp();
423      return _running?t-start_time:start_time;
424    }
425
426
427    ///@}
428  };
429
430  ///Same as \ref Timer but prints a report on destruction.
431
432  ///Same as \ref Timer but prints a report on destruction.
433  ///This example shows its usage.
434  ///\code
435  ///  void myAlg(ListGraph &g,int n)
436  ///  {
437  ///    TimeReport TR("Running time of myAlg: ");
438  ///    ... //Here comes the algorithm
439  ///  }
440  ///\endcode
441  ///
442  ///\sa Timer
443  ///\sa NoTimeReport
444  ///\todo There is no test case for this
445  class TimeReport : public Timer
446  {
447    std::string _title;
448    std::ostream &_os;
449  public:
450    ///\e
451
452    ///\param title This text will be printed before the ellapsed time.
453    ///\param os The stream to print the report to.
454    ///\param run Sets whether the timer should start immediately.
455
456    TimeReport(std::string title,std::ostream &os=std::cerr,bool run=true)
457      : Timer(run), _title(title), _os(os){}
458    ///\e Prints the ellapsed time on destruction.
459    ~TimeReport()
460    {
461      _os << _title << *this << std::endl;
462    }
463  };
464     
465  ///'Do nothing' version of \ref TimeReport
466
467  ///\sa TimeReport
468  ///
469  class NoTimeReport
470  {
471  public:
472    ///\e
473    NoTimeReport(std::string,std::ostream &,bool) {}
474    ///\e
475    NoTimeReport(std::string,std::ostream &) {}
476    ///\e
477    NoTimeReport(std::string) {}
478    ///\e Do nothing.
479    ~NoTimeReport() {}
480
481    operator TimeStamp () const { return TimeStamp(); }
482    void reset() {}
483    void start() {}
484    void stop() {}
485    void halt() {}
486    int running() { return 0; }
487    void restart() {}
488    double userTime() const { return 0; }
489    double systemTime() const { return 0; }
490    double cUserTime() const { return 0; }
491    double cSystemTime() const { return 0; }
492    double realTime() const { return 0; }
493  };
494     
495  ///Tool to measure the running time more exactly.
496 
497  ///This function calls \c f several times and returns the average
498  ///running time. The number of the executions will be choosen in such a way
499  ///that the full real running time will be roughly between \c min_time
500  ///and <tt>2*min_time</tt>.
501  ///\param f the function object to be measured.
502  ///\param min_time the minimum total running time.
503  ///\retval num if it is not \c NULL, then *num will contain the actual
504  ///        number of execution of \c f.
505  ///\retval full_time if it is not \c NULL, then *full_time
506  ///        will contain the actual
507  ///        total running time.
508  ///\return The average running time of \c f.
509 
510  template<class F>
511  TimeStamp runningTimeTest(F f,double min_time=10,int *num = NULL,
512                        TimeStamp *full_time=NULL)
513  {
514    Timer t;
515    TimeStamp full;
516    int total=0;
517    for(int tn=1;tn < 1<<24; tn*=2) {
518      for(;total<tn;total++) f();
519      full=t;
520      if(full.realTime()>min_time) {
521        if(num) *num=total;
522        if(full_time) *full_time=full;
523      return full/total;
524      }
525    }
526    return TimeStamp();
527  }
528 
529  /// @} 
530
531
532} //namespace lemon
533
534#endif //LEMON_TIME_MEASURE_H
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