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/Compiler.h"
19#include "llvm/Support/DataTypes.h"
20#include "llvm/ADT/StringRef.h"
21#include <cassert>
22#include <string>
23#include <vector>
24#include <utility>
25
26namespace llvm {
27
28class Timer;
29class TimerGroup;
30class raw_ostream;
31
32class TimeRecord {
33  double WallTime;       // Wall clock time elapsed in seconds
34  double UserTime;       // User time elapsed
35  double SystemTime;     // System time elapsed
36  ssize_t MemUsed;       // Memory allocated (in bytes)
37public:
38  TimeRecord() : WallTime(0), UserTime(0), SystemTime(0), MemUsed(0) {}
39
40  /// getCurrentTime - Get the current time and memory usage.  If Start is true
41  /// we get the memory usage before the time, otherwise we get time before
42  /// memory usage.  This matters if the time to get the memory usage is
43  /// significant and shouldn't be counted as part of a duration.
44  static TimeRecord getCurrentTime(bool Start = true);
45
46  double getProcessTime() const { return UserTime+SystemTime; }
47  double getUserTime() const { return UserTime; }
48  double getSystemTime() const { return SystemTime; }
49  double getWallTime() const { return WallTime; }
50  ssize_t getMemUsed() const { return MemUsed; }
51
52
53  // operator< - Allow sorting.
54  bool operator<(const TimeRecord &T) const {
55    // Sort by Wall Time elapsed, as it is the only thing really accurate
56    return WallTime < T.WallTime;
57  }
58
59  void operator+=(const TimeRecord &RHS) {
60    WallTime   += RHS.WallTime;
61    UserTime   += RHS.UserTime;
62    SystemTime += RHS.SystemTime;
63    MemUsed    += RHS.MemUsed;
64  }
65  void operator-=(const TimeRecord &RHS) {
66    WallTime   -= RHS.WallTime;
67    UserTime   -= RHS.UserTime;
68    SystemTime -= RHS.SystemTime;
69    MemUsed    -= RHS.MemUsed;
70  }
71
72  /// print - Print the current timer to standard error, and reset the "Started"
73  /// flag.
74  void print(const TimeRecord &Total, raw_ostream &OS) const;
75};
76
77/// Timer - This class is used to track the amount of time spent between
78/// invocations of its startTimer()/stopTimer() methods.  Given appropriate OS
79/// support it can also keep track of the RSS of the program at various points.
80/// By default, the Timer will print the amount of time it has captured to
81/// standard error when the laster timer is destroyed, otherwise it is printed
82/// when its TimerGroup is destroyed.  Timers do not print their information
83/// if they are never started.
84///
85class Timer {
86  TimeRecord Time;
87  std::string Name;      // The name of this time variable.
88  bool Started;          // Has this time variable ever been started?
89  TimerGroup *TG;        // The TimerGroup this Timer is in.
90
91  Timer **Prev, *Next;   // Doubly linked list of timers in the group.
92public:
93  explicit Timer(StringRef N) : TG(0) { init(N); }
94  Timer(StringRef N, TimerGroup &tg) : TG(0) { init(N, tg); }
95  Timer(const Timer &RHS) : TG(0) {
96    assert(RHS.TG == 0 && "Can only copy uninitialized timers");
97  }
98  const Timer &operator=(const Timer &T) {
99    assert(TG == 0 && T.TG == 0 && "Can only assign uninit timers");
100    return *this;
101  }
102  ~Timer();
103
104  // Create an uninitialized timer, client must use 'init'.
105  explicit Timer() : TG(0) {}
106  void init(StringRef N);
107  void init(StringRef N, TimerGroup &tg);
108
109  const std::string &getName() const { return Name; }
110  bool isInitialized() const { return TG != 0; }
111
112  /// startTimer - Start the timer running.  Time between calls to
113  /// startTimer/stopTimer is counted by the Timer class.  Note that these calls
114  /// must be correctly paired.
115  ///
116  void startTimer();
117
118  /// stopTimer - Stop the timer.
119  ///
120  void stopTimer();
121
122private:
123  friend class TimerGroup;
124};
125
126
127/// The TimeRegion class is used as a helper class to call the startTimer() and
128/// stopTimer() methods of the Timer class.  When the object is constructed, it
129/// starts the timer specified as it's argument.  When it is destroyed, it stops
130/// the relevant timer.  This makes it easy to time a region of code.
131///
132class TimeRegion {
133  Timer *T;
134  TimeRegion(const TimeRegion &) LLVM_DELETED_FUNCTION;
135public:
136  explicit TimeRegion(Timer &t) : T(&t) {
137    T->startTimer();
138  }
139  explicit TimeRegion(Timer *t) : T(t) {
140    if (T) T->startTimer();
141  }
142  ~TimeRegion() {
143    if (T) T->stopTimer();
144  }
145};
146
147
148/// NamedRegionTimer - This class is basically a combination of TimeRegion and
149/// Timer.  It allows you to declare a new timer, AND specify the region to
150/// time, all in one statement.  All timers with the same name are merged.  This
151/// is primarily used for debugging and for hunting performance problems.
152///
153struct NamedRegionTimer : public TimeRegion {
154  explicit NamedRegionTimer(StringRef Name,
155                            bool Enabled = true);
156  explicit NamedRegionTimer(StringRef Name, StringRef GroupName,
157                            bool Enabled = true);
158};
159
160
161/// The TimerGroup class is used to group together related timers into a single
162/// report that is printed when the TimerGroup is destroyed.  It is illegal to
163/// destroy a TimerGroup object before all of the Timers in it are gone.  A
164/// TimerGroup can be specified for a newly created timer in its constructor.
165///
166class TimerGroup {
167  std::string Name;
168  Timer *FirstTimer;   // First timer in the group.
169  std::vector<std::pair<TimeRecord, std::string> > TimersToPrint;
170
171  TimerGroup **Prev, *Next; // Doubly linked list of TimerGroup's.
172  TimerGroup(const TimerGroup &TG) LLVM_DELETED_FUNCTION;
173  void operator=(const TimerGroup &TG) LLVM_DELETED_FUNCTION;
174public:
175  explicit TimerGroup(StringRef name);
176  ~TimerGroup();
177
178  void setName(StringRef name) { Name.assign(name.begin(), name.end()); }
179
180  /// print - Print any started timers in this group and zero them.
181  void print(raw_ostream &OS);
182
183  /// printAll - This static method prints all timers and clears them all out.
184  static void printAll(raw_ostream &OS);
185
186private:
187  friend class Timer;
188  void addTimer(Timer &T);
189  void removeTimer(Timer &T);
190  void PrintQueuedTimers(raw_ostream &OS);
191};
192
193} // End llvm namespace
194
195#endif
196