COIN-OR::LEMON - Graph Library

source: lemon-1.0/lemon/time_measure.h @ 142:8b703d177341

Last change on this file since 142:8b703d177341 was 126:e1dd2a70737c, checked in by Balazs Dezso <deba@…>, 12 years ago

MinGW compatible time measure + changes in its internals

File size: 14.1 KB
Line 
1/* -*- C++ -*-
2 *
3 * This file is a part of LEMON, a generic C++ optimization library
4 *
5 * Copyright (C) 2003-2008
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 <windows.h>
28#include <cmath>
29#else
30#include <sys/times.h>
31#include <sys/time.h>
32#endif
33
34#include <fstream>
35#include <iostream>
36
37namespace lemon {
38
39  /// \addtogroup timecount
40  /// @{
41
42  /// A class to store (cpu)time instances.
43
44  /// This class stores five time values.
45  /// - a real time
46  /// - a user cpu time
47  /// - a system cpu time
48  /// - a user cpu time of children
49  /// - a system cpu time of children
50  ///
51  /// TimeStamp's can be added to or substracted from each other and
52  /// they can be pushed to a stream.
53  ///
54  /// In most cases, perhaps the \ref Timer or the \ref TimeReport
55  /// class is what you want to use instead.
56  ///
57  ///\author Alpar Juttner
58
59  class TimeStamp
60  {
61    double utime;
62    double stime;
63    double cutime;
64    double cstime;
65    double rtime;
66 
67    void _reset() {
68      utime = stime = cutime = cstime = rtime = 0;
69    }
70
71  public:
72
73    ///Read the current time values of the process
74    void stamp()
75    {
76#ifndef WIN32
77      timeval tv;
78      gettimeofday(&tv, 0);
79      rtime=tv.tv_sec+double(tv.tv_usec)/1e6;
80
81      tms ts;
82      double tck=sysconf(_SC_CLK_TCK);
83      times(&ts);
84      utime=ts.tms_utime/tck;
85      stime=ts.tms_stime/tck;
86      cutime=ts.tms_cutime/tck;
87      cstime=ts.tms_cstime/tck;
88#else
89      static const double ch = 4294967296.0e-7;
90      static const double cl = 1.0e-7;
91
92      FILETIME system;
93      GetSystemTimeAsFileTime(&system);
94      rtime = ch * system.dwHighDateTime + cl * system.dwLowDateTime;
95
96      FILETIME create, exit, kernel, user;
97      if (GetProcessTimes(GetCurrentProcess(),&create, &exit, &kernel, &user)) {
98        utime = ch * user.dwHighDateTime + cl * user.dwLowDateTime;
99        stime = ch * kernel.dwHighDateTime + cl * kernel.dwLowDateTime;
100        cutime = 0;
101        cstime = 0;
102      } else {
103        rtime = 0;
104        utime = 0;
105        stime = 0;
106        cutime = 0;
107        cstime = 0;
108      }
109#endif     
110    }
111 
112    /// Constructor initializing with zero
113    TimeStamp()
114    { _reset(); }
115    ///Constructor initializing with the current time values of the process
116    TimeStamp(void *) { stamp();}
117 
118    ///Set every time value to zero
119    TimeStamp &reset() {_reset();return *this;}
120
121    ///\e
122    TimeStamp &operator+=(const TimeStamp &b)
123    {
124      utime+=b.utime;
125      stime+=b.stime;
126      cutime+=b.cutime;
127      cstime+=b.cstime;
128      rtime+=b.rtime;
129      return *this;
130    }
131    ///\e
132    TimeStamp operator+(const TimeStamp &b) const
133    {
134      TimeStamp t(*this);
135      return t+=b;
136    }
137    ///\e
138    TimeStamp &operator-=(const TimeStamp &b)
139    {
140      utime-=b.utime;
141      stime-=b.stime;
142      cutime-=b.cutime;
143      cstime-=b.cstime;
144      rtime-=b.rtime;
145      return *this;
146    }
147    ///\e
148    TimeStamp operator-(const TimeStamp &b) const
149    {
150      TimeStamp t(*this);
151      return t-=b;
152    }
153    ///\e
154    TimeStamp &operator*=(double b)
155    {
156      utime*=b;
157      stime*=b;
158      cutime*=b;
159      cstime*=b;
160      rtime*=b;
161      return *this;
162    }
163    ///\e
164    TimeStamp operator*(double b) const
165    {
166      TimeStamp t(*this);
167      return t*=b;
168    }
169    friend TimeStamp operator*(double b,const TimeStamp &t);
170    ///\e
171    TimeStamp &operator/=(double b)
172    {
173      utime/=b;
174      stime/=b;
175      cutime/=b;
176      cstime/=b;
177      rtime/=b;
178      return *this;
179    }
180    ///\e
181    TimeStamp operator/(double b) const
182    {
183      TimeStamp t(*this);
184      return t/=b;
185    }
186    ///The time ellapsed since the last call of stamp()
187    TimeStamp ellapsed() const
188    {
189      TimeStamp t(NULL);
190      return t-*this;
191    }
192 
193    friend std::ostream& operator<<(std::ostream& os,const TimeStamp &t);
194 
195    ///Gives back the user time of the process
196    double userTime() const
197    {
198      return utime;
199    }
200    ///Gives back the system time of the process
201    double systemTime() const
202    {
203      return stime;
204    }
205    ///Gives back the user time of the process' children
206
207    ///\note On <tt>WIN32</tt> platform this value is not calculated.
208    ///
209    double cUserTime() const
210    {
211      return cutime;
212    }
213    ///Gives back the user time of the process' children
214
215    ///\note On <tt>WIN32</tt> platform this value is not calculated.
216    ///
217    double cSystemTime() const
218    {
219      return cstime;
220    }
221    ///Gives back the real time
222    double realTime() const {return rtime;}
223  };
224
225  TimeStamp operator*(double b,const TimeStamp &t)
226  {
227    return t*b;
228  }
229 
230  ///Prints the time counters
231
232  ///Prints the time counters in the following form:
233  ///
234  /// <tt>u: XX.XXs s: XX.XXs cu: XX.XXs cs: XX.XXs real: XX.XXs</tt>
235  ///
236  /// where the values are the
237  /// \li \c u: user cpu time,
238  /// \li \c s: system cpu time,
239  /// \li \c cu: user cpu time of children,
240  /// \li \c cs: system cpu time of children,
241  /// \li \c real: real time.
242  /// \relates TimeStamp
243  /// \note On <tt>WIN32</tt> platform the cummulative values are not
244  /// calculated.
245  inline std::ostream& operator<<(std::ostream& os,const TimeStamp &t)
246  {
247    os << "u: " << t.userTime() <<
248      "s, s: " << t.systemTime() <<
249      "s, cu: " << t.cUserTime() <<
250      "s, cs: " << t.cSystemTime() <<
251      "s, real: " << t.realTime() << "s";
252    return os;
253  }
254
255  ///Class for measuring the cpu time and real time usage of the process
256
257  ///Class for measuring the cpu time and real time usage of the process.
258  ///It is quite easy-to-use, here is a short example.
259  ///\code
260  /// #include<lemon/time_measure.h>
261  /// #include<iostream>
262  ///
263  /// int main()
264  /// {
265  ///
266  ///   ...
267  ///
268  ///   Timer t;
269  ///   doSomething();
270  ///   std::cout << t << '\n';
271  ///   t.restart();
272  ///   doSomethingElse();
273  ///   std::cout << t << '\n';
274  ///
275  ///   ...
276  ///
277  /// }
278  ///\endcode
279  ///
280  ///The \ref Timer can also be \ref stop() "stopped" and
281  ///\ref start() "started" again, so it is possible to compute collected
282  ///running times.
283  ///
284  ///\warning Depending on the operation system and its actual configuration
285  ///the time counters have a certain (10ms on a typical Linux system)
286  ///granularity.
287  ///Therefore this tool is not appropriate to measure very short times.
288  ///Also, if you start and stop the timer very frequently, it could lead to
289  ///distorted results.
290  ///
291  ///\note If you want to measure the running time of the execution of a certain
292  ///function, consider the usage of \ref TimeReport instead.
293  ///
294  ///\todo This shouldn't be Unix (Linux) specific.
295  ///\sa TimeReport
296  ///
297  ///\author Alpar Juttner
298  class Timer
299  {
300    int _running; //Timer is running iff _running>0; (_running>=0 always holds)
301    TimeStamp start_time; //This is the relativ start-time if the timer
302                          //is _running, the collected _running time otherwise.
303   
304    void _reset() {if(_running) start_time.stamp(); else start_time.reset();}
305 
306  public:
307    ///Constructor.
308
309    ///\param run indicates whether or not the timer starts immediately.
310    ///
311    Timer(bool run=true) :_running(run) {_reset();}
312
313    ///\name Control the state of the timer
314    ///Basically a Timer can be either running or stopped,
315    ///but it provides a bit finer control on the execution.
316    ///The \ref Timer also counts the number of \ref start()
317    ///executions, and is stops only after the same amount (or more)
318    ///\ref stop() "stop()"s. This can be useful e.g. to compute the running time
319    ///of recursive functions.
320    ///
321
322    ///@{
323
324    ///Reset and stop the time counters
325
326    ///This function resets and stops the time counters
327    ///\sa restart()
328    void reset()
329    {
330      _running=0;
331      _reset();
332    }
333
334    ///Start the time counters
335   
336    ///This function starts the time counters.
337    ///
338    ///If the timer is started more than ones, it will remain running
339    ///until the same amount of \ref stop() is called.
340    ///\sa stop()
341    void start()
342    {
343      if(_running) _running++;
344      else {
345        _running=1;
346        TimeStamp t;
347        t.stamp();
348        start_time=t-start_time;
349      }
350    }
351
352   
353    ///Stop the time counters
354
355    ///This function stops the time counters. If start() was executed more than
356    ///once, then the same number of stop() execution is necessary the really
357    ///stop the timer.
358    ///
359    ///\sa halt()
360    ///\sa start()
361    ///\sa restart()
362    ///\sa reset()
363
364    void stop()
365    {
366      if(_running && !--_running) {
367        TimeStamp t;
368        t.stamp();
369        start_time=t-start_time;
370      }
371    }
372
373    ///Halt (i.e stop immediately) the time counters
374
375    ///This function stops immediately the time counters, i.e. <tt>t.halt()</tt>
376    ///is a faster
377    ///equivalent of the following.
378    ///\code
379    ///  while(t.running()) t.stop()
380    ///\endcode
381    ///
382    ///
383    ///\sa stop()
384    ///\sa restart()
385    ///\sa reset()
386
387    void halt()
388    {
389      if(_running) {
390        _running=0;
391        TimeStamp t;
392        t.stamp();
393        start_time=t-start_time;
394      }
395    }
396
397    ///Returns the running state of the timer
398
399    ///This function returns the number of stop() exections that is
400    ///necessary to really stop the timer.
401    ///For example the timer
402    ///is running if and only if the return value is \c true
403    ///(i.e. greater than
404    ///zero).
405    int running()  { return _running; }
406   
407   
408    ///Restart the time counters
409
410    ///This function is a shorthand for
411    ///a reset() and a start() calls.
412    ///
413    void restart()
414    {
415      reset();
416      start();
417    }
418   
419    ///@}
420
421    ///\name Query Functions for the ellapsed time
422
423    ///@{
424
425    ///Gives back the ellapsed user time of the process
426    double userTime() const
427    {
428      return operator TimeStamp().userTime();
429    }
430    ///Gives back the ellapsed system time of the process
431    double systemTime() const
432    {
433      return operator TimeStamp().systemTime();
434    }
435    ///Gives back the ellapsed user time of the process' children
436
437    ///\note On <tt>WIN32</tt> platform this value is not calculated.
438    ///
439    double cUserTime() const
440    {
441      return operator TimeStamp().cUserTime();
442    }
443    ///Gives back the ellapsed user time of the process' children
444
445    ///\note On <tt>WIN32</tt> platform this value is not calculated.
446    ///
447    double cSystemTime() const
448    {
449      return operator TimeStamp().cSystemTime();
450    }
451    ///Gives back the ellapsed real time
452    double realTime() const
453    {
454      return operator TimeStamp().realTime();
455    }
456    ///Computes the ellapsed time
457
458    ///This conversion computes the ellapsed time, therefore you can print
459    ///the ellapsed time like this.
460    ///\code
461    ///  Timer t;
462    ///  doSomething();
463    ///  std::cout << t << '\n';
464    ///\endcode
465    operator TimeStamp () const
466    {
467      TimeStamp t;
468      t.stamp();
469      return _running?t-start_time:start_time;
470    }
471
472
473    ///@}
474  };
475
476  ///Same as \ref Timer but prints a report on destruction.
477
478  ///Same as \ref Timer but prints a report on destruction.
479  ///This example shows its usage.
480  ///\code
481  ///  void myAlg(ListGraph &g,int n)
482  ///  {
483  ///    TimeReport tr("Running time of myAlg: ");
484  ///    ... //Here comes the algorithm
485  ///  }
486  ///\endcode
487  ///
488  ///\sa Timer
489  ///\sa NoTimeReport
490  ///\todo There is no test case for this
491  class TimeReport : public Timer
492  {
493    std::string _title;
494    std::ostream &_os;
495  public:
496    ///\e
497
498    ///\param title This text will be printed before the ellapsed time.
499    ///\param os The stream to print the report to.
500    ///\param run Sets whether the timer should start immediately.
501
502    TimeReport(std::string title,std::ostream &os=std::cerr,bool run=true)
503      : Timer(run), _title(title), _os(os){}
504    ///\e Prints the ellapsed time on destruction.
505    ~TimeReport()
506    {
507      _os << _title << *this << std::endl;
508    }
509  };
510     
511  ///'Do nothing' version of \ref TimeReport
512
513  ///\sa TimeReport
514  ///
515  class NoTimeReport
516  {
517  public:
518    ///\e
519    NoTimeReport(std::string,std::ostream &,bool) {}
520    ///\e
521    NoTimeReport(std::string,std::ostream &) {}
522    ///\e
523    NoTimeReport(std::string) {}
524    ///\e Do nothing.
525    ~NoTimeReport() {}
526
527    operator TimeStamp () const { return TimeStamp(); }
528    void reset() {}
529    void start() {}
530    void stop() {}
531    void halt() {}
532    int running() { return 0; }
533    void restart() {}
534    double userTime() const { return 0; }
535    double systemTime() const { return 0; }
536    double cUserTime() const { return 0; }
537    double cSystemTime() const { return 0; }
538    double realTime() const { return 0; }
539  };
540     
541  ///Tool to measure the running time more exactly.
542 
543  ///This function calls \c f several times and returns the average
544  ///running time. The number of the executions will be choosen in such a way
545  ///that the full real running time will be roughly between \c min_time
546  ///and <tt>2*min_time</tt>.
547  ///\param f the function object to be measured.
548  ///\param min_time the minimum total running time.
549  ///\retval num if it is not \c NULL, then the actual
550  ///        number of execution of \c f will be written into <tt>*num</tt>.
551  ///\retval full_time if it is not \c NULL, then the actual
552  ///        total running time will be written into <tt>*full_time</tt>.
553  ///\return The average running time of \c f.
554 
555  template<class F>
556  TimeStamp runningTimeTest(F f,double min_time=10,unsigned int *num = NULL,
557                            TimeStamp *full_time=NULL)
558  {
559    TimeStamp full;
560    unsigned int total=0;
561    Timer t;
562    for(unsigned int tn=1;tn <= 1U<<31 && full.realTime()<=min_time; tn*=2) {
563      for(;total<tn;total++) f();
564      full=t;
565    }
566    if(num) *num=total;
567    if(full_time) *full_time=full;
568    return full/total;
569  }
570 
571  /// @} 
572
573
574} //namespace lemon
575
576#endif //LEMON_TIME_MEASURE_H
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