1 | //===-- llvm/Support/Timer.h - Interval Timing Support ----------*- C++ -*-===// |
2 | // |
3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
4 | // See https://llvm.org/LICENSE.txt for license information. |
5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
6 | // |
7 | //===----------------------------------------------------------------------===// |
8 | |
9 | #ifndef LLVM_SUPPORT_TIMER_H |
10 | #define LLVM_SUPPORT_TIMER_H |
11 | |
12 | #include "llvm/ADT/StringMap.h" |
13 | #include "llvm/ADT/StringRef.h" |
14 | #include "llvm/Support/DataTypes.h" |
15 | #include <cassert> |
16 | #include <memory> |
17 | #include <string> |
18 | #include <vector> |
19 | |
20 | namespace llvm { |
21 | |
22 | class TimerGroup; |
23 | class raw_ostream; |
24 | |
25 | class TimeRecord { |
26 | double WallTime = 0.0; ///< Wall clock time elapsed in seconds. |
27 | double UserTime = 0.0; ///< User time elapsed. |
28 | double SystemTime = 0.0; ///< System time elapsed. |
29 | ssize_t MemUsed = 0; ///< Memory allocated (in bytes). |
30 | uint64_t InstructionsExecuted = 0; ///< Number of instructions executed |
31 | public: |
32 | TimeRecord() = default; |
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 | uint64_t getInstructionsExecuted() const { return InstructionsExecuted; } |
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 | InstructionsExecuted += RHS.InstructionsExecuted; |
58 | } |
59 | void operator-=(const TimeRecord &RHS) { |
60 | WallTime -= RHS.WallTime; |
61 | UserTime -= RHS.UserTime; |
62 | SystemTime -= RHS.SystemTime; |
63 | MemUsed -= RHS.MemUsed; |
64 | InstructionsExecuted -= RHS.InstructionsExecuted; |
65 | } |
66 | |
67 | /// Print the current time record to \p OS, with a breakdown showing |
68 | /// contributions to the \p Total time record. |
69 | void print(const TimeRecord &Total, raw_ostream &OS) const; |
70 | }; |
71 | |
72 | /// This class is used to track the amount of time spent between invocations of |
73 | /// its startTimer()/stopTimer() methods. Given appropriate OS support it can |
74 | /// also keep track of the RSS of the program at various points. By default, |
75 | /// the Timer will print the amount of time it has captured to standard error |
76 | /// when the last timer is destroyed, otherwise it is printed when its |
77 | /// TimerGroup is destroyed. Timers do not print their information if they are |
78 | /// never started. |
79 | class Timer { |
80 | TimeRecord Time; ///< The total time captured. |
81 | TimeRecord StartTime; ///< The time startTimer() was last called. |
82 | std::string Name; ///< The name of this time variable. |
83 | std::string Description; ///< Description of this time variable. |
84 | bool Running = false; ///< Is the timer currently running? |
85 | bool Triggered = false; ///< Has the timer ever been triggered? |
86 | TimerGroup *TG = nullptr; ///< The TimerGroup this Timer is in. |
87 | |
88 | Timer **Prev = nullptr; ///< Pointer to \p Next of previous timer in group. |
89 | Timer *Next = nullptr; ///< Next timer in the group. |
90 | public: |
91 | explicit Timer(StringRef TimerName, StringRef TimerDescription) { |
92 | init(TimerName, TimerDescription); |
93 | } |
94 | Timer(StringRef TimerName, StringRef TimerDescription, TimerGroup &tg) { |
95 | init(TimerName, TimerDescription, tg); |
96 | } |
97 | Timer(const Timer &RHS) { |
98 | assert(!RHS.TG && "Can only copy uninitialized timers" ); |
99 | } |
100 | const Timer &operator=(const Timer &T) { |
101 | assert(!TG && !T.TG && "Can only assign uninit timers" ); |
102 | return *this; |
103 | } |
104 | ~Timer(); |
105 | |
106 | /// Create an uninitialized timer, client must use 'init'. |
107 | explicit Timer() = default; |
108 | void init(StringRef TimerName, StringRef TimerDescription); |
109 | void init(StringRef TimerName, StringRef TimerDescription, TimerGroup &tg); |
110 | |
111 | const std::string &getName() const { return Name; } |
112 | const std::string &getDescription() const { return Description; } |
113 | bool isInitialized() const { return TG != nullptr; } |
114 | |
115 | /// Check if the timer is currently running. |
116 | bool isRunning() const { return Running; } |
117 | |
118 | /// Check if startTimer() has ever been called on this timer. |
119 | bool hasTriggered() const { return Triggered; } |
120 | |
121 | /// Start the timer running. Time between calls to startTimer/stopTimer is |
122 | /// counted by the Timer class. Note that these calls must be correctly |
123 | /// paired. |
124 | void startTimer(); |
125 | |
126 | /// Stop the timer. |
127 | void stopTimer(); |
128 | |
129 | /// Clear the timer state. |
130 | void clear(); |
131 | |
132 | /// Return the duration for which this timer has been running. |
133 | TimeRecord getTotalTime() const { return Time; } |
134 | |
135 | private: |
136 | friend class TimerGroup; |
137 | }; |
138 | |
139 | /// The TimeRegion class is used as a helper class to call the startTimer() and |
140 | /// stopTimer() methods of the Timer class. When the object is constructed, it |
141 | /// starts the timer specified as its argument. When it is destroyed, it stops |
142 | /// the relevant timer. This makes it easy to time a region of code. |
143 | class TimeRegion { |
144 | Timer *T; |
145 | TimeRegion(const TimeRegion &) = delete; |
146 | |
147 | public: |
148 | explicit TimeRegion(Timer &t) : T(&t) { |
149 | T->startTimer(); |
150 | } |
151 | explicit TimeRegion(Timer *t) : T(t) { |
152 | if (T) T->startTimer(); |
153 | } |
154 | ~TimeRegion() { |
155 | if (T) T->stopTimer(); |
156 | } |
157 | }; |
158 | |
159 | /// This class is basically a combination of TimeRegion and Timer. It allows |
160 | /// you to declare a new timer, AND specify the region to time, all in one |
161 | /// statement. All timers with the same name are merged. This is primarily |
162 | /// used for debugging and for hunting performance problems. |
163 | struct NamedRegionTimer : public TimeRegion { |
164 | explicit NamedRegionTimer(StringRef Name, StringRef Description, |
165 | StringRef GroupName, |
166 | StringRef GroupDescription, bool Enabled = true); |
167 | }; |
168 | |
169 | /// The TimerGroup class is used to group together related timers into a single |
170 | /// report that is printed when the TimerGroup is destroyed. It is illegal to |
171 | /// destroy a TimerGroup object before all of the Timers in it are gone. A |
172 | /// TimerGroup can be specified for a newly created timer in its constructor. |
173 | class TimerGroup { |
174 | struct PrintRecord { |
175 | TimeRecord Time; |
176 | std::string Name; |
177 | std::string Description; |
178 | |
179 | PrintRecord(const PrintRecord &Other) = default; |
180 | PrintRecord &operator=(const PrintRecord &Other) = default; |
181 | PrintRecord(const TimeRecord &Time, const std::string &Name, |
182 | const std::string &Description) |
183 | : Time(Time), Name(Name), Description(Description) {} |
184 | |
185 | bool operator <(const PrintRecord &Other) const { |
186 | return Time < Other.Time; |
187 | } |
188 | }; |
189 | std::string Name; |
190 | std::string Description; |
191 | Timer *FirstTimer = nullptr; ///< First timer in the group. |
192 | std::vector<PrintRecord> TimersToPrint; |
193 | |
194 | TimerGroup **Prev; ///< Pointer to Next field of previous timergroup in list. |
195 | TimerGroup *Next; ///< Pointer to next timergroup in list. |
196 | TimerGroup(const TimerGroup &TG) = delete; |
197 | void operator=(const TimerGroup &TG) = delete; |
198 | |
199 | public: |
200 | explicit TimerGroup(StringRef Name, StringRef Description); |
201 | |
202 | explicit TimerGroup(StringRef Name, StringRef Description, |
203 | const StringMap<TimeRecord> &Records); |
204 | |
205 | ~TimerGroup(); |
206 | |
207 | void setName(StringRef NewName, StringRef NewDescription) { |
208 | Name.assign(first: NewName.begin(), last: NewName.end()); |
209 | Description.assign(first: NewDescription.begin(), last: NewDescription.end()); |
210 | } |
211 | |
212 | /// Print any started timers in this group, optionally resetting timers after |
213 | /// printing them. |
214 | void print(raw_ostream &OS, bool ResetAfterPrint = false); |
215 | |
216 | /// Clear all timers in this group. |
217 | void clear(); |
218 | |
219 | /// This static method prints all timers. |
220 | static void printAll(raw_ostream &OS); |
221 | |
222 | /// Clear out all timers. This is mostly used to disable automatic |
223 | /// printing on shutdown, when timers have already been printed explicitly |
224 | /// using \c printAll or \c printJSONValues. |
225 | static void clearAll(); |
226 | |
227 | const char *printJSONValues(raw_ostream &OS, const char *delim); |
228 | |
229 | /// Prints all timers as JSON key/value pairs. |
230 | static const char *printAllJSONValues(raw_ostream &OS, const char *delim); |
231 | |
232 | /// Ensure global objects required for statistics printing are initialized. |
233 | /// This function is used by the Statistic code to ensure correct order of |
234 | /// global constructors and destructors. |
235 | static void constructForStatistics(); |
236 | |
237 | /// This makes the default group unmanaged, and lets the user manage the |
238 | /// group's lifetime. |
239 | static std::unique_ptr<TimerGroup> aquireDefaultGroup(); |
240 | |
241 | private: |
242 | friend class Timer; |
243 | friend void PrintStatisticsJSON(raw_ostream &OS); |
244 | void addTimer(Timer &T); |
245 | void removeTimer(Timer &T); |
246 | void prepareToPrintList(bool reset_time = false); |
247 | void PrintQueuedTimers(raw_ostream &OS); |
248 | void printJSONValue(raw_ostream &OS, const PrintRecord &R, |
249 | const char *suffix, double Value); |
250 | }; |
251 | |
252 | } // end namespace llvm |
253 | |
254 | #endif |
255 | |