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/StringMap.h"
14#include "llvm/ADT/StringRef.h"
15#include "llvm/Support/DataTypes.h"
16#include <cassert>
17#include <string>
18#include <utility>
19#include <vector>
20
21namespace llvm {
22
23class Timer;
24class TimerGroup;
25class raw_ostream;
26
27class TimeRecord {
28 double WallTime; ///< Wall clock time elapsed in seconds.
29 double UserTime; ///< User time elapsed.
30 double SystemTime; ///< System time elapsed.
31 ssize_t MemUsed; ///< Memory allocated (in bytes).
32public:
33 TimeRecord() : WallTime(0), UserTime(0), SystemTime(0), MemUsed(0) {}
34
35 /// Get the current time and memory usage. If Start is true we get the memory
36 /// usage before the time, otherwise we get time before memory usage. This
37 /// matters if the time to get the memory usage is significant and shouldn't
38 /// be counted as part of a duration.
39 static TimeRecord getCurrentTime(bool Start = true);
40
41 double getProcessTime() const { return UserTime + SystemTime; }
42 double getUserTime() const { return UserTime; }
43 double getSystemTime() const { return SystemTime; }
44 double getWallTime() const { return WallTime; }
45 ssize_t getMemUsed() const { return MemUsed; }
46
47 bool operator<(const TimeRecord &T) const {
48 // Sort by Wall Time elapsed, as it is the only thing really accurate
49 return WallTime < T.WallTime;
50 }
51
52 void operator+=(const TimeRecord &RHS) {
53 WallTime += RHS.WallTime;
54 UserTime += RHS.UserTime;
55 SystemTime += RHS.SystemTime;
56 MemUsed += RHS.MemUsed;
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
65 /// Print the current time record to \p OS, with a breakdown showing
66 /// contributions to the \p Total time record.
67 void print(const TimeRecord &Total, raw_ostream &OS) const;
68};
69
70/// This class is used to track the amount of time spent between invocations of
71/// its startTimer()/stopTimer() methods. Given appropriate OS support it can
72/// also keep track of the RSS of the program at various points. By default,
73/// the Timer will print the amount of time it has captured to standard error
74/// when the last timer is destroyed, otherwise it is printed when its
75/// TimerGroup is destroyed. Timers do not print their information if they are
76/// never started.
77class Timer {
78 TimeRecord Time; ///< The total time captured.
79 TimeRecord StartTime; ///< The time startTimer() was last called.
80 std::string Name; ///< The name of this time variable.
81 std::string Description; ///< Description of this time variable.
82 bool Running; ///< Is the timer currently running?
83 bool Triggered; ///< Has the timer ever been triggered?
84 TimerGroup *TG = nullptr; ///< The TimerGroup this Timer is in.
85
86 Timer **Prev; ///< Pointer to \p Next of previous timer in group.
87 Timer *Next; ///< Next timer in the group.
88public:
89 explicit Timer(StringRef Name, StringRef Description) {
90 init(Name, Description);
91 }
92 Timer(StringRef Name, StringRef Description, TimerGroup &tg) {
93 init(Name, Description, tg);
94 }
95 Timer(const Timer &RHS) {
96 assert(!RHS.TG && "Can only copy uninitialized timers");
97 }
98 const Timer &operator=(const Timer &T) {
99 assert(!TG && !T.TG && "Can only assign uninit timers");
100 return *this;
101 }
102 ~Timer();
103
104 /// Create an uninitialized timer, client must use 'init'.
105 explicit Timer() {}
106 void init(StringRef Name, StringRef Description);
107 void init(StringRef Name, StringRef Description, TimerGroup &tg);
108
109 const std::string &getName() const { return Name; }
110 const std::string &getDescription() const { return Description; }
111 bool isInitialized() const { return TG != nullptr; }
112
113 /// Check if the timer is currently running.
114 bool isRunning() const { return Running; }
115
116 /// Check if startTimer() has ever been called on this timer.
117 bool hasTriggered() const { return Triggered; }
118
119 /// Start the timer running. Time between calls to startTimer/stopTimer is
120 /// counted by the Timer class. Note that these calls must be correctly
121 /// paired.
122 void startTimer();
123
124 /// Stop the timer.
125 void stopTimer();
126
127 /// Clear the timer state.
128 void clear();
129
130 /// Return the duration for which this timer has been running.
131 TimeRecord getTotalTime() const { return Time; }
132
133private:
134 friend class TimerGroup;
135};
136
137/// The TimeRegion class is used as a helper class to call the startTimer() and
138/// stopTimer() methods of the Timer class. When the object is constructed, it
139/// starts the timer specified as its argument. When it is destroyed, it stops
140/// the relevant timer. This makes it easy to time a region of code.
141class TimeRegion {
142 Timer *T;
143 TimeRegion(const TimeRegion &) = delete;
144
145public:
146 explicit TimeRegion(Timer &t) : T(&t) {
147 T->startTimer();
148 }
149 explicit TimeRegion(Timer *t) : T(t) {
150 if (T) T->startTimer();
151 }
152 ~TimeRegion() {
153 if (T) T->stopTimer();
154 }
155};
156
157/// This class is basically a combination of TimeRegion and Timer. It allows
158/// you to declare a new timer, AND specify the region to time, all in one
159/// statement. All timers with the same name are merged. This is primarily
160/// used for debugging and for hunting performance problems.
161struct NamedRegionTimer : public TimeRegion {
162 explicit NamedRegionTimer(StringRef Name, StringRef Description,
163 StringRef GroupName,
164 StringRef GroupDescription, bool Enabled = true);
165};
166
167/// The TimerGroup class is used to group together related timers into a single
168/// report that is printed when the TimerGroup is destroyed. It is illegal to
169/// destroy a TimerGroup object before all of the Timers in it are gone. A
170/// TimerGroup can be specified for a newly created timer in its constructor.
171class TimerGroup {
172 struct PrintRecord {
173 TimeRecord Time;
174 std::string Name;
175 std::string Description;
176
177 PrintRecord(const PrintRecord &Other) = default;
178 PrintRecord(const TimeRecord &Time, const std::string &Name,
179 const std::string &Description)
180 : Time(Time), Name(Name), Description(Description) {}
181
182 bool operator <(const PrintRecord &Other) const {
183 return Time < Other.Time;
184 }
185 };
186 std::string Name;
187 std::string Description;
188 Timer *FirstTimer = nullptr; ///< First timer in the group.
189 std::vector<PrintRecord> TimersToPrint;
190
191 TimerGroup **Prev; ///< Pointer to Next field of previous timergroup in list.
192 TimerGroup *Next; ///< Pointer to next timergroup in list.
193 TimerGroup(const TimerGroup &TG) = delete;
194 void operator=(const TimerGroup &TG) = delete;
195
196public:
197 explicit TimerGroup(StringRef Name, StringRef Description);
198
199 explicit TimerGroup(StringRef Name, StringRef Description,
200 const StringMap<TimeRecord> &Records);
201
202 ~TimerGroup();
203
204 void setName(StringRef NewName, StringRef NewDescription) {
205 Name.assign(NewName.begin(), NewName.end());
206 Description.assign(NewDescription.begin(), NewDescription.end());
207 }
208
209 /// Print any started timers in this group.
210 void print(raw_ostream &OS);
211
212 /// Clear all timers in this group.
213 void clear();
214
215 /// This static method prints all timers.
216 static void printAll(raw_ostream &OS);
217
218 /// Clear out all timers. This is mostly used to disable automatic
219 /// printing on shutdown, when timers have already been printed explicitly
220 /// using \c printAll or \c printJSONValues.
221 static void clearAll();
222
223 const char *printJSONValues(raw_ostream &OS, const char *delim);
224
225 /// Prints all timers as JSON key/value pairs.
226 static const char *printAllJSONValues(raw_ostream &OS, const char *delim);
227
228 /// Ensure global timer group lists are initialized. This function is mostly
229 /// used by the Statistic code to influence the construction and destruction
230 /// order of the global timer lists.
231 static void ConstructTimerLists();
232private:
233 friend class Timer;
234 friend void PrintStatisticsJSON(raw_ostream &OS);
235 void addTimer(Timer &T);
236 void removeTimer(Timer &T);
237 void prepareToPrintList();
238 void PrintQueuedTimers(raw_ostream &OS);
239 void printJSONValue(raw_ostream &OS, const PrintRecord &R,
240 const char *suffix, double Value);
241};
242
243} // end namespace llvm
244
245#endif
246