Timer.h revision b0d0f5b473b6110a9e72d823f2f2c4c52928a1bf 
1//===-- Support/Timer.h - Interval Timing Support ---------------*- C++ -*-===//
2//
3// This file defines three classes: Timer, TimeRegion, and TimerGroup.
4//
5// The Timer class is used to track the amount of time spent between invocations
6// of it's startTimer()/stopTimer() methods.  Given appropriate OS support it
7// can also keep track of the RSS of the program at various points.  By default,
8// the Timer will print the amount of time it has captured to standard error
9// when the laster timer is destroyed, otherwise it is printed when it's
10// TimerGroup is destroyed.  Timer's do not print their information if they are
11// never started.
12//
13// The TimeRegion class is used as a helper class to call the startTimer() and
14// stopTimer() methods of the Timer class.  When the object is constructed, it
15// starts the timer specified as it's argument.  When it is destroyed, it stops
16// the relevant timer.  This makes it easy to time a region of code.
17//
18// The TimerGroup class is used to group together related timers into a single
19// report that is printed when the TimerGroup is destroyed.  It is illegal to
20// destroy a TimerGroup object before all of the Timers in it are gone.  A
21// TimerGroup can be specified for a newly created timer in its constructor.
22//
23//===----------------------------------------------------------------------===//
24
25#ifndef SUPPORT_TIMER_H
26#define SUPPORT_TIMER_H
27
28#include <string>
29#include <vector>
30
31class TimerGroup;
32
33class Timer {
34  double Elapsed;        // Wall clock time elapsed in seconds
35  double UserTime;       // User time elapsed
36  double SystemTime;     // System time elapsed
37  unsigned long MaxRSS;  // Maximum resident set size (in bytes)
38  unsigned long RSSTemp; // Temp for calculating maxrss
39  std::string Name;      // The name of this time variable
40  bool Started;          // Has this time variable ever been started?
41  TimerGroup *TG;        // The TimerGroup this Timer is in.
42public:
43  Timer(const std::string &N);
44  Timer(const std::string &N, TimerGroup &tg);
45  Timer(const Timer &T);
46  ~Timer();
47
48  double getProcessTime() const { return UserTime+SystemTime; }
49  double getWallTime() const { return Elapsed; }
50  unsigned long getMaxRSS() const { return MaxRSS; }
51  std::string   getName() const { return Name; }
52
53  const Timer &operator=(const Timer &T) {
54    Elapsed = T.Elapsed;
55    UserTime = T.UserTime;
56    SystemTime = T.SystemTime;
57    MaxRSS = T.MaxRSS;
58    RSSTemp = T.RSSTemp;
59    Name = T.Name;
60    Started = T.Started;
61    assert (TG == T.TG && "Can only assign timers in the same TimerGroup!");
62    return *this;
63  }
64
65  // operator< - Allow sorting...
66  bool operator<(const Timer &T) const {
67    // Sort by Wall Time elapsed, as it is the only thing really accurate
68    return Elapsed < T.Elapsed;
69  }
70  bool operator>(const Timer &T) const { return T.operator<(*this); }
71
72  /// startTimer - Start the timer running.  Time between calls to
73  /// startTimer/stopTimer is counted by the Timer class.  Note that these calls
74  /// must be correctly paired.
75  ///
76  void startTimer();
77
78  /// stopTimer - Stop the timer.
79  ///
80  void stopTimer();
81
82  /// print - Print the current timer to standard error, and reset the "Started"
83  /// flag.
84  void print(const Timer &Total);
85
86private:
87  friend class TimerGroup;
88
89  // Copy ctor, initialize with no TG member.
90  Timer(bool, const Timer &T);
91
92  /// sum - Add the time accumulated in the specified timer into this timer.
93  ///
94  void sum(const Timer &T);
95};
96
97
98class TimeRegion {
99  Timer &T;
100  TimeRegion(const TimeRegion &); // DO NOT IMPLEMENT
101public:
102  TimeRegion(Timer &t) : T(t) {
103    T.startTimer();
104  }
105  ~TimeRegion() {
106    T.stopTimer();
107  }
108};
109
110class TimerGroup {
111  std::string Name;
112  unsigned NumTimers;
113  std::vector<Timer> TimersToPrint;
114public:
115  TimerGroup(const std::string &name) : Name(name), NumTimers(0) {}
116  ~TimerGroup() {
117    assert(NumTimers == 0 &&
118           "TimerGroup destroyed before all contained timers!");
119  }
120
121private:
122  friend class Timer;
123  void addTimer() { ++NumTimers; }
124  void removeTimer();
125  void addTimerToPrint(const Timer &T) {
126    TimersToPrint.push_back(Timer(true, T));
127  }
128};
129
130#endif
131