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#ifndef LLVM_SUPPORT_TIMER_H
11#define LLVM_SUPPORT_TIMER_H
12
13#include "llvm/ADT/StringRef.h"
14#include "llvm/Support/DataTypes.h"
15#include <cassert>
16#include <string>
17#include <utility>
18#include <vector>
19
20namespace llvm {
21
22class Timer;
23class TimerGroup;
24class raw_ostream;
25
26class TimeRecord {
27  double WallTime;       ///< Wall clock time elapsed in seconds.
28  double UserTime;       ///< User time elapsed.
29  double SystemTime;     ///< System time elapsed.
30  ssize_t MemUsed;       ///< Memory allocated (in bytes).
31public:
32  TimeRecord() : WallTime(0), UserTime(0), SystemTime(0), MemUsed(0) {}
33
34  /// Get the current time and memory usage.  If Start is true we get the memory
35  /// usage before the time, otherwise we get time before memory usage.  This
36  /// matters if the time to get the memory usage is significant and shouldn't
37  /// be counted as part of a duration.
38  static TimeRecord getCurrentTime(bool Start = true);
39
40  double getProcessTime() const { return UserTime + SystemTime; }
41  double getUserTime() const { return UserTime; }
42  double getSystemTime() const { return SystemTime; }
43  double getWallTime() const { return WallTime; }
44  ssize_t getMemUsed() const { return MemUsed; }
45
46  bool operator<(const TimeRecord &T) const {
47    // Sort by Wall Time elapsed, as it is the only thing really accurate
48    return WallTime < T.WallTime;
49  }
50
51  void operator+=(const TimeRecord &RHS) {
52    WallTime   += RHS.WallTime;
53    UserTime   += RHS.UserTime;
54    SystemTime += RHS.SystemTime;
55    MemUsed    += RHS.MemUsed;
56  }
57  void operator-=(const TimeRecord &RHS) {
58    WallTime   -= RHS.WallTime;
59    UserTime   -= RHS.UserTime;
60    SystemTime -= RHS.SystemTime;
61    MemUsed    -= RHS.MemUsed;
62  }
63
64  /// Print the current time record to \p OS, with a breakdown showing
65  /// contributions to the \p Total time record.
66  void print(const TimeRecord &Total, raw_ostream &OS) const;
67};
68
69/// This class is used to track the amount of time spent between invocations of
70/// its startTimer()/stopTimer() methods.  Given appropriate OS support it can
71/// also keep track of the RSS of the program at various points.  By default,
72/// the Timer will print the amount of time it has captured to standard error
73/// when the last timer is destroyed, otherwise it is printed when its
74/// TimerGroup is destroyed.  Timers do not print their information if they are
75/// never started.
76class Timer {
77  TimeRecord Time;          ///< The total time captured.
78  TimeRecord StartTime;     ///< The time startTimer() was last called.
79  std::string Name;         ///< The name of this time variable.
80  std::string Description;  ///< Description of this time variable.
81  bool Running;             ///< Is the timer currently running?
82  bool Triggered;           ///< Has the timer ever been triggered?
83  TimerGroup *TG = nullptr; ///< The TimerGroup this Timer is in.
84
85  Timer **Prev;             ///< Pointer to \p Next of previous timer in group.
86  Timer *Next;              ///< Next timer in the group.
87public:
88  explicit Timer(StringRef Name, StringRef Description) {
89    init(Name, Description);
90  }
91  Timer(StringRef Name, StringRef Description, TimerGroup &tg) {
92    init(Name, Description, tg);
93  }
94  Timer(const Timer &RHS) {
95    assert(!RHS.TG && "Can only copy uninitialized timers");
96  }
97  const Timer &operator=(const Timer &T) {
98    assert(!TG && !T.TG && "Can only assign uninit timers");
99    return *this;
100  }
101  ~Timer();
102
103  /// Create an uninitialized timer, client must use 'init'.
104  explicit Timer() {}
105  void init(StringRef Name, StringRef Description);
106  void init(StringRef Name, StringRef Description, TimerGroup &tg);
107
108  const std::string &getName() const { return Name; }
109  const std::string &getDescription() const { return Description; }
110  bool isInitialized() const { return TG != nullptr; }
111
112  /// Check if the timer is currently running.
113  bool isRunning() const { return Running; }
114
115  /// Check if startTimer() has ever been called on this timer.
116  bool hasTriggered() const { return Triggered; }
117
118  /// Start the timer running.  Time between calls to startTimer/stopTimer is
119  /// counted by the Timer class.  Note that these calls must be correctly
120  /// paired.
121  void startTimer();
122
123  /// Stop the timer.
124  void stopTimer();
125
126  /// Clear the timer state.
127  void clear();
128
129  /// Return the duration for which this timer has been running.
130  TimeRecord getTotalTime() const { return Time; }
131
132private:
133  friend class TimerGroup;
134};
135
136/// The TimeRegion class is used as a helper class to call the startTimer() and
137/// stopTimer() methods of the Timer class.  When the object is constructed, it
138/// starts the timer specified as its argument.  When it is destroyed, it stops
139/// the relevant timer.  This makes it easy to time a region of code.
140class TimeRegion {
141  Timer *T;
142  TimeRegion(const TimeRegion &) = delete;
143
144public:
145  explicit TimeRegion(Timer &t) : T(&t) {
146    T->startTimer();
147  }
148  explicit TimeRegion(Timer *t) : T(t) {
149    if (T) T->startTimer();
150  }
151  ~TimeRegion() {
152    if (T) T->stopTimer();
153  }
154};
155
156/// This class is basically a combination of TimeRegion and Timer.  It allows
157/// you to declare a new timer, AND specify the region to time, all in one
158/// statement.  All timers with the same name are merged.  This is primarily
159/// used for debugging and for hunting performance problems.
160struct NamedRegionTimer : public TimeRegion {
161  explicit NamedRegionTimer(StringRef Name, StringRef Description,
162                            StringRef GroupName,
163                            StringRef GroupDescription, bool Enabled = true);
164};
165
166/// The TimerGroup class is used to group together related timers into a single
167/// report that is printed when the TimerGroup is destroyed.  It is illegal to
168/// destroy a TimerGroup object before all of the Timers in it are gone.  A
169/// TimerGroup can be specified for a newly created timer in its constructor.
170class TimerGroup {
171  struct PrintRecord {
172    TimeRecord Time;
173    std::string Name;
174    std::string Description;
175
176    PrintRecord(const PrintRecord &Other) = default;
177    PrintRecord(const TimeRecord &Time, const std::string &Name,
178                const std::string &Description)
179      : Time(Time), Name(Name), Description(Description) {}
180
181    bool operator <(const PrintRecord &Other) const {
182      return Time < Other.Time;
183    }
184  };
185  std::string Name;
186  std::string Description;
187  Timer *FirstTimer = nullptr; ///< First timer in the group.
188  std::vector<PrintRecord> TimersToPrint;
189
190  TimerGroup **Prev; ///< Pointer to Next field of previous timergroup in list.
191  TimerGroup *Next;  ///< Pointer to next timergroup in list.
192  TimerGroup(const TimerGroup &TG) = delete;
193  void operator=(const TimerGroup &TG) = delete;
194
195public:
196  explicit TimerGroup(StringRef Name, StringRef Description);
197  ~TimerGroup();
198
199  void setName(StringRef NewName, StringRef NewDescription) {
200    Name.assign(NewName.begin(), NewName.end());
201    Description.assign(NewDescription.begin(), NewDescription.end());
202  }
203
204  /// Print any started timers in this group and zero them.
205  void print(raw_ostream &OS);
206
207  /// This static method prints all timers and clears them all out.
208  static void printAll(raw_ostream &OS);
209
210  /// Prints all timers as JSON key/value pairs, and clears them all out.
211  static const char *printAllJSONValues(raw_ostream &OS, const char *delim);
212
213  /// Ensure global timer group lists are initialized. This function is mostly
214  /// used by the Statistic code to influence the construction and destruction
215  /// order of the global timer lists.
216  static void ConstructTimerLists();
217private:
218  friend class Timer;
219  friend void PrintStatisticsJSON(raw_ostream &OS);
220  void addTimer(Timer &T);
221  void removeTimer(Timer &T);
222  void prepareToPrintList();
223  void PrintQueuedTimers(raw_ostream &OS);
224  void printJSONValue(raw_ostream &OS, const PrintRecord &R,
225                      const char *suffix, double Value);
226  const char *printJSONValues(raw_ostream &OS, const char *delim);
227};
228
229} // end namespace llvm
230
231#endif
232