1//===-- llvm/Support/Timer.h - Interval Timing Support ----------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines three classes: Timer, TimeRegion, and TimerGroup,
11// documented below.
12//
13//===----------------------------------------------------------------------===//
14
15#ifndef LLVM_SUPPORT_TIMER_H
16#define LLVM_SUPPORT_TIMER_H
17
18#include "llvm/Support/DataTypes.h"
19#include "llvm/ADT/StringRef.h"
20#include <cassert>
21#include <string>
22#include <vector>
23#include <utility>
24
25namespace llvm {
26
27class Timer;
28class TimerGroup;
29class raw_ostream;
30
31class TimeRecord {
32  double WallTime;       // Wall clock time elapsed in seconds
33  double UserTime;       // User time elapsed
34  double SystemTime;     // System time elapsed
35  ssize_t MemUsed;       // Memory allocated (in bytes)
36public:
37  TimeRecord() : WallTime(0), UserTime(0), SystemTime(0), MemUsed(0) {}
38
39  /// getCurrentTime - Get the current time and memory usage.  If Start is true
40  /// we get the memory usage before the time, otherwise we get time before
41  /// memory usage.  This matters if the time to get the memory usage is
42  /// significant and shouldn't be counted as part of a duration.
43  static TimeRecord getCurrentTime(bool Start = true);
44
45  double getProcessTime() const { return UserTime+SystemTime; }
46  double getUserTime() const { return UserTime; }
47  double getSystemTime() const { return SystemTime; }
48  double getWallTime() const { return WallTime; }
49  ssize_t getMemUsed() const { return MemUsed; }
50
51
52  // operator< - Allow sorting.
53  bool operator<(const TimeRecord &T) const {
54    // Sort by Wall Time elapsed, as it is the only thing really accurate
55    return WallTime < T.WallTime;
56  }
57
58  void operator+=(const TimeRecord &RHS) {
59    WallTime   += RHS.WallTime;
60    UserTime   += RHS.UserTime;
61    SystemTime += RHS.SystemTime;
62    MemUsed    += RHS.MemUsed;
63  }
64  void operator-=(const TimeRecord &RHS) {
65    WallTime   -= RHS.WallTime;
66    UserTime   -= RHS.UserTime;
67    SystemTime -= RHS.SystemTime;
68    MemUsed    -= RHS.MemUsed;
69  }
70
71  /// print - Print the current timer to standard error, and reset the "Started"
72  /// flag.
73  void print(const TimeRecord &Total, raw_ostream &OS) const;
74};
75
76/// Timer - This class is used to track the amount of time spent between
77/// invocations of its startTimer()/stopTimer() methods.  Given appropriate OS
78/// support it can also keep track of the RSS of the program at various points.
79/// By default, the Timer will print the amount of time it has captured to
80/// standard error when the laster timer is destroyed, otherwise it is printed
81/// when its TimerGroup is destroyed.  Timers do not print their information
82/// if they are never started.
83///
84class Timer {
85  TimeRecord Time;
86  std::string Name;      // The name of this time variable.
87  bool Started;          // Has this time variable ever been started?
88  TimerGroup *TG;        // The TimerGroup this Timer is in.
89
90  Timer **Prev, *Next;   // Doubly linked list of timers in the group.
91public:
92  explicit Timer(StringRef N) : TG(0) { init(N); }
93  Timer(StringRef N, TimerGroup &tg) : TG(0) { init(N, tg); }
94  Timer(const Timer &RHS) : TG(0) {
95    assert(RHS.TG == 0 && "Can only copy uninitialized timers");
96  }
97  const Timer &operator=(const Timer &T) {
98    assert(TG == 0 && T.TG == 0 && "Can only assign uninit timers");
99    return *this;
100  }
101  ~Timer();
102
103  // Create an uninitialized timer, client must use 'init'.
104  explicit Timer() : TG(0) {}
105  void init(StringRef N);
106  void init(StringRef N, TimerGroup &tg);
107
108  const std::string &getName() const { return Name; }
109  bool isInitialized() const { return TG != 0; }
110
111  /// startTimer - Start the timer running.  Time between calls to
112  /// startTimer/stopTimer is counted by the Timer class.  Note that these calls
113  /// must be correctly paired.
114  ///
115  void startTimer();
116
117  /// stopTimer - Stop the timer.
118  ///
119  void stopTimer();
120
121private:
122  friend class TimerGroup;
123};
124
125
126/// The TimeRegion class is used as a helper class to call the startTimer() and
127/// stopTimer() methods of the Timer class.  When the object is constructed, it
128/// starts the timer specified as it's argument.  When it is destroyed, it stops
129/// the relevant timer.  This makes it easy to time a region of code.
130///
131class TimeRegion {
132  Timer *T;
133  TimeRegion(const TimeRegion &); // DO NOT IMPLEMENT
134public:
135  explicit TimeRegion(Timer &t) : T(&t) {
136    T->startTimer();
137  }
138  explicit TimeRegion(Timer *t) : T(t) {
139    if (T) T->startTimer();
140  }
141  ~TimeRegion() {
142    if (T) T->stopTimer();
143  }
144};
145
146
147/// NamedRegionTimer - This class is basically a combination of TimeRegion and
148/// Timer.  It allows you to declare a new timer, AND specify the region to
149/// time, all in one statement.  All timers with the same name are merged.  This
150/// is primarily used for debugging and for hunting performance problems.
151///
152struct NamedRegionTimer : public TimeRegion {
153  explicit NamedRegionTimer(StringRef Name,
154                            bool Enabled = true);
155  explicit NamedRegionTimer(StringRef Name, StringRef GroupName,
156                            bool Enabled = true);
157};
158
159
160/// The TimerGroup class is used to group together related timers into a single
161/// report that is printed when the TimerGroup is destroyed.  It is illegal to
162/// destroy a TimerGroup object before all of the Timers in it are gone.  A
163/// TimerGroup can be specified for a newly created timer in its constructor.
164///
165class TimerGroup {
166  std::string Name;
167  Timer *FirstTimer;   // First timer in the group.
168  std::vector<std::pair<TimeRecord, std::string> > TimersToPrint;
169
170  TimerGroup **Prev, *Next; // Doubly linked list of TimerGroup's.
171  TimerGroup(const TimerGroup &TG);      // DO NOT IMPLEMENT
172  void operator=(const TimerGroup &TG);  // DO NOT IMPLEMENT
173public:
174  explicit TimerGroup(StringRef name);
175  ~TimerGroup();
176
177  void setName(StringRef name) { Name.assign(name.begin(), name.end()); }
178
179  /// print - Print any started timers in this group and zero them.
180  void print(raw_ostream &OS);
181
182  /// printAll - This static method prints all timers and clears them all out.
183  static void printAll(raw_ostream &OS);
184
185private:
186  friend class Timer;
187  void addTimer(Timer &T);
188  void removeTimer(Timer &T);
189  void PrintQueuedTimers(raw_ostream &OS);
190};
191
192} // End llvm namespace
193
194#endif
195