COIN-OR::LEMON - Graph Library

source: lemon-1.2/lemon/time_measure.h @ 209:765619b7cbb2

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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) 2003-2008
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#define WIN32_LEAN_AND_MEAN
28#define NOMINMAX
29#include <windows.h>
30#include <cmath>
31#else
32#include <sys/times.h>
33#include <sys/time.h>
34#endif
35
36#include <string>
37#include <fstream>
38#include <iostream>
39
40namespace lemon {
41
42  /// \addtogroup timecount
43  /// @{
44
45  /// A class to store (cpu)time instances.
46
47  /// This class stores five time values.
48  /// - a real time
49  /// - a user cpu time
50  /// - a system cpu time
51  /// - a user cpu time of children
52  /// - a system cpu time of children
53  ///
54  /// TimeStamp's can be added to or substracted from each other and
55  /// they can be pushed to a stream.
56  ///
57  /// In most cases, perhaps the \ref Timer or the \ref TimeReport
58  /// class is what you want to use instead.
59
60  class TimeStamp
61  {
62    double utime;
63    double stime;
64    double cutime;
65    double cstime;
66    double rtime;
67
68    void _reset() {
69      utime = stime = cutime = cstime = rtime = 0;
70    }
71
72  public:
73
74    ///Read the current time values of the process
75    void stamp()
76    {
77#ifndef WIN32
78      timeval tv;
79      gettimeofday(&tv, 0);
80      rtime=tv.tv_sec+double(tv.tv_usec)/1e6;
81
82      tms ts;
83      double tck=sysconf(_SC_CLK_TCK);
84      times(&ts);
85      utime=ts.tms_utime/tck;
86      stime=ts.tms_stime/tck;
87      cutime=ts.tms_cutime/tck;
88      cstime=ts.tms_cstime/tck;
89#else
90      static const double ch = 4294967296.0e-7;
91      static const double cl = 1.0e-7;
92
93      FILETIME system;
94      GetSystemTimeAsFileTime(&system);
95      rtime = ch * system.dwHighDateTime + cl * system.dwLowDateTime;
96
97      FILETIME create, exit, kernel, user;
98      if (GetProcessTimes(GetCurrentProcess(),&create, &exit, &kernel, &user)) {
99        utime = ch * user.dwHighDateTime + cl * user.dwLowDateTime;
100        stime = ch * kernel.dwHighDateTime + cl * kernel.dwLowDateTime;
101        cutime = 0;
102        cstime = 0;
103      } else {
104        rtime = 0;
105        utime = 0;
106        stime = 0;
107        cutime = 0;
108        cstime = 0;
109      }
110#endif
111    }
112
113    /// Constructor initializing with zero
114    TimeStamp()
115    { _reset(); }
116    ///Constructor initializing with the current time values of the process
117    TimeStamp(void *) { stamp();}
118
119    ///Set every time value to zero
120    TimeStamp &reset() {_reset();return *this;}
121
122    ///\e
123    TimeStamp &operator+=(const TimeStamp &b)
124    {
125      utime+=b.utime;
126      stime+=b.stime;
127      cutime+=b.cutime;
128      cstime+=b.cstime;
129      rtime+=b.rtime;
130      return *this;
131    }
132    ///\e
133    TimeStamp operator+(const TimeStamp &b) const
134    {
135      TimeStamp t(*this);
136      return t+=b;
137    }
138    ///\e
139    TimeStamp &operator-=(const TimeStamp &b)
140    {
141      utime-=b.utime;
142      stime-=b.stime;
143      cutime-=b.cutime;
144      cstime-=b.cstime;
145      rtime-=b.rtime;
146      return *this;
147    }
148    ///\e
149    TimeStamp operator-(const TimeStamp &b) const
150    {
151      TimeStamp t(*this);
152      return t-=b;
153    }
154    ///\e
155    TimeStamp &operator*=(double b)
156    {
157      utime*=b;
158      stime*=b;
159      cutime*=b;
160      cstime*=b;
161      rtime*=b;
162      return *this;
163    }
164    ///\e
165    TimeStamp operator*(double b) const
166    {
167      TimeStamp t(*this);
168      return t*=b;
169    }
170    friend TimeStamp operator*(double b,const TimeStamp &t);
171    ///\e
172    TimeStamp &operator/=(double b)
173    {
174      utime/=b;
175      stime/=b;
176      cutime/=b;
177      cstime/=b;
178      rtime/=b;
179      return *this;
180    }
181    ///\e
182    TimeStamp operator/(double b) const
183    {
184      TimeStamp t(*this);
185      return t/=b;
186    }
187    ///The time ellapsed since the last call of stamp()
188    TimeStamp ellapsed() const
189    {
190      TimeStamp t(NULL);
191      return t-*this;
192    }
193
194    friend std::ostream& operator<<(std::ostream& os,const TimeStamp &t);
195
196    ///Gives back the user time of the process
197    double userTime() const
198    {
199      return utime;
200    }
201    ///Gives back the system time of the process
202    double systemTime() const
203    {
204      return stime;
205    }
206    ///Gives back the user time of the process' children
207
208    ///\note On <tt>WIN32</tt> platform this value is not calculated.
209    ///
210    double cUserTime() const
211    {
212      return cutime;
213    }
214    ///Gives back the user time of the process' children
215
216    ///\note On <tt>WIN32</tt> platform this value is not calculated.
217    ///
218    double cSystemTime() const
219    {
220      return cstime;
221    }
222    ///Gives back the real time
223    double realTime() const {return rtime;}
224  };
225
226  TimeStamp operator*(double b,const TimeStamp &t)
227  {
228    return t*b;
229  }
230
231  ///Prints the time counters
232
233  ///Prints the time counters in the following form:
234  ///
235  /// <tt>u: XX.XXs s: XX.XXs cu: XX.XXs cs: XX.XXs real: XX.XXs</tt>
236  ///
237  /// where the values are the
238  /// \li \c u: user cpu time,
239  /// \li \c s: system cpu time,
240  /// \li \c cu: user cpu time of children,
241  /// \li \c cs: system cpu time of children,
242  /// \li \c real: real time.
243  /// \relates TimeStamp
244  /// \note On <tt>WIN32</tt> platform the cummulative values are not
245  /// calculated.
246  inline std::ostream& operator<<(std::ostream& os,const TimeStamp &t)
247  {
248    os << "u: " << t.userTime() <<
249      "s, s: " << t.systemTime() <<
250      "s, cu: " << t.cUserTime() <<
251      "s, cs: " << t.cSystemTime() <<
252      "s, real: " << t.realTime() << "s";
253    return os;
254  }
255
256  ///Class for measuring the cpu time and real time usage of the process
257
258  ///Class for measuring the cpu time and real time usage of the process.
259  ///It is quite easy-to-use, here is a short example.
260  ///\code
261  /// #include<lemon/time_measure.h>
262  /// #include<iostream>
263  ///
264  /// int main()
265  /// {
266  ///
267  ///   ...
268  ///
269  ///   Timer t;
270  ///   doSomething();
271  ///   std::cout << t << '\n';
272  ///   t.restart();
273  ///   doSomethingElse();
274  ///   std::cout << t << '\n';
275  ///
276  ///   ...
277  ///
278  /// }
279  ///\endcode
280  ///
281  ///The \ref Timer can also be \ref stop() "stopped" and
282  ///\ref start() "started" again, so it is possible to compute collected
283  ///running times.
284  ///
285  ///\warning Depending on the operation system and its actual configuration
286  ///the time counters have a certain (10ms on a typical Linux system)
287  ///granularity.
288  ///Therefore this tool is not appropriate to measure very short times.
289  ///Also, if you start and stop the timer very frequently, it could lead to
290  ///distorted results.
291  ///
292  ///\note If you want to measure the running time of the execution of a certain
293  ///function, consider the usage of \ref TimeReport instead.
294  ///
295  ///\todo This shouldn't be Unix (Linux) specific.
296  ///\sa TimeReport
297  class Timer
298  {
299    int _running; //Timer is running iff _running>0; (_running>=0 always holds)
300    TimeStamp start_time; //This is the relativ start-time if the timer
301                          //is _running, the collected _running time otherwise.
302
303    void _reset() {if(_running) start_time.stamp(); else start_time.reset();}
304
305  public:
306    ///Constructor.
307
308    ///\param run indicates whether or not the timer starts immediately.
309    ///
310    Timer(bool run=true) :_running(run) {_reset();}
311
312    ///\name Control the state of the timer
313    ///Basically a Timer can be either running or stopped,
314    ///but it provides a bit finer control on the execution.
315    ///The \ref Timer also counts the number of \ref start()
316    ///executions, and is stops only after the same amount (or more)
317    ///\ref stop() "stop()"s. This can be useful e.g. to compute the running time
318    ///of recursive functions.
319    ///
320
321    ///@{
322
323    ///Reset and stop the time counters
324
325    ///This function resets and stops the time counters
326    ///\sa restart()
327    void reset()
328    {
329      _running=0;
330      _reset();
331    }
332
333    ///Start the time counters
334
335    ///This function starts the time counters.
336    ///
337    ///If the timer is started more than ones, it will remain running
338    ///until the same amount of \ref stop() is called.
339    ///\sa stop()
340    void start()
341    {
342      if(_running) _running++;
343      else {
344        _running=1;
345        TimeStamp t;
346        t.stamp();
347        start_time=t-start_time;
348      }
349    }
350
351
352    ///Stop the time counters
353
354    ///This function stops the time counters. If start() was executed more than
355    ///once, then the same number of stop() execution is necessary the really
356    ///stop the timer.
357    ///
358    ///\sa halt()
359    ///\sa start()
360    ///\sa restart()
361    ///\sa reset()
362
363    void stop()
364    {
365      if(_running && !--_running) {
366        TimeStamp t;
367        t.stamp();
368        start_time=t-start_time;
369      }
370    }
371
372    ///Halt (i.e stop immediately) the time counters
373
374    ///This function stops immediately the time counters, i.e. <tt>t.halt()</tt>
375    ///is a faster
376    ///equivalent of the following.
377    ///\code
378    ///  while(t.running()) t.stop()
379    ///\endcode
380    ///
381    ///
382    ///\sa stop()
383    ///\sa restart()
384    ///\sa reset()
385
386    void halt()
387    {
388      if(_running) {
389        _running=0;
390        TimeStamp t;
391        t.stamp();
392        start_time=t-start_time;
393      }
394    }
395
396    ///Returns the running state of the timer
397
398    ///This function returns the number of stop() exections that is
399    ///necessary to really stop the timer.
400    ///For example the timer
401    ///is running if and only if the return value is \c true
402    ///(i.e. greater than
403    ///zero).
404    int running()  { return _running; }
405
406
407    ///Restart the time counters
408
409    ///This function is a shorthand for
410    ///a reset() and a start() calls.
411    ///
412    void restart()
413    {
414      reset();
415      start();
416    }
417
418    ///@}
419
420    ///\name Query Functions for the ellapsed time
421
422    ///@{
423
424    ///Gives back the ellapsed user time of the process
425    double userTime() const
426    {
427      return operator TimeStamp().userTime();
428    }
429    ///Gives back the ellapsed system time of the process
430    double systemTime() const
431    {
432      return operator TimeStamp().systemTime();
433    }
434    ///Gives back the ellapsed user time of the process' children
435
436    ///\note On <tt>WIN32</tt> platform this value is not calculated.
437    ///
438    double cUserTime() const
439    {
440      return operator TimeStamp().cUserTime();
441    }
442    ///Gives back the ellapsed user time of the process' children
443
444    ///\note On <tt>WIN32</tt> platform this value is not calculated.
445    ///
446    double cSystemTime() const
447    {
448      return operator TimeStamp().cSystemTime();
449    }
450    ///Gives back the ellapsed real time
451    double realTime() const
452    {
453      return operator TimeStamp().realTime();
454    }
455    ///Computes the ellapsed time
456
457    ///This conversion computes the ellapsed time, therefore you can print
458    ///the ellapsed time like this.
459    ///\code
460    ///  Timer t;
461    ///  doSomething();
462    ///  std::cout << t << '\n';
463    ///\endcode
464    operator TimeStamp () const
465    {
466      TimeStamp t;
467      t.stamp();
468      return _running?t-start_time:start_time;
469    }
470
471
472    ///@}
473  };
474
475  ///Same as \ref Timer but prints a report on destruction.
476
477  ///Same as \ref Timer but prints a report on destruction.
478  ///This example shows its usage.
479  ///\code
480  ///  void myAlg(ListGraph &g,int n)
481  ///  {
482  ///    TimeReport tr("Running time of myAlg: ");
483  ///    ... //Here comes the algorithm
484  ///  }
485  ///\endcode
486  ///
487  ///\sa Timer
488  ///\sa NoTimeReport
489  ///\todo There is no test case for this
490  class TimeReport : public Timer
491  {
492    std::string _title;
493    std::ostream &_os;
494  public:
495    ///\e
496
497    ///\param title This text will be printed before the ellapsed time.
498    ///\param os The stream to print the report to.
499    ///\param run Sets whether the timer should start immediately.
500
501    TimeReport(std::string title,std::ostream &os=std::cerr,bool run=true)
502      : Timer(run), _title(title), _os(os){}
503    ///\e Prints the ellapsed time on destruction.
504    ~TimeReport()
505    {
506      _os << _title << *this << std::endl;
507    }
508  };
509
510  ///'Do nothing' version of \ref TimeReport
511
512  ///\sa TimeReport
513  ///
514  class NoTimeReport
515  {
516  public:
517    ///\e
518    NoTimeReport(std::string,std::ostream &,bool) {}
519    ///\e
520    NoTimeReport(std::string,std::ostream &) {}
521    ///\e
522    NoTimeReport(std::string) {}
523    ///\e Do nothing.
524    ~NoTimeReport() {}
525
526    operator TimeStamp () const { return TimeStamp(); }
527    void reset() {}
528    void start() {}
529    void stop() {}
530    void halt() {}
531    int running() { return 0; }
532    void restart() {}
533    double userTime() const { return 0; }
534    double systemTime() const { return 0; }
535    double cUserTime() const { return 0; }
536    double cSystemTime() const { return 0; }
537    double realTime() const { return 0; }
538  };
539
540  ///Tool to measure the running time more exactly.
541
542  ///This function calls \c f several times and returns the average
543  ///running time. The number of the executions will be choosen in such a way
544  ///that the full real running time will be roughly between \c min_time
545  ///and <tt>2*min_time</tt>.
546  ///\param f the function object to be measured.
547  ///\param min_time the minimum total running time.
548  ///\retval num if it is not \c NULL, then the actual
549  ///        number of execution of \c f will be written into <tt>*num</tt>.
550  ///\retval full_time if it is not \c NULL, then the actual
551  ///        total running time will be written into <tt>*full_time</tt>.
552  ///\return The average running time of \c f.
553
554  template<class F>
555  TimeStamp runningTimeTest(F f,double min_time=10,unsigned int *num = NULL,
556                            TimeStamp *full_time=NULL)
557  {
558    TimeStamp full;
559    unsigned int total=0;
560    Timer t;
561    for(unsigned int tn=1;tn <= 1U<<31 && full.realTime()<=min_time; tn*=2) {
562      for(;total<tn;total++) f();
563      full=t;
564    }
565    if(num) *num=total;
566    if(full_time) *full_time=full;
567    return full/total;
568  }
569
570  /// @}
571
572
573} //namespace lemon
574
575#endif //LEMON_TIME_MEASURE_H
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