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 <string> 17 #include <utility> 18 #include <vector> 19 20 namespace llvm { 21 22 class Timer; 23 class TimerGroup; 24 class raw_ostream; 25 26 class 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). 31 public: TimeRecord()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 getProcessTime()40 double getProcessTime() const { return UserTime + SystemTime; } getUserTime()41 double getUserTime() const { return UserTime; } getSystemTime()42 double getSystemTime() const { return SystemTime; } getWallTime()43 double getWallTime() const { return WallTime; } getMemUsed()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. 76 class 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. 87 public: Timer(StringRef Name,StringRef Description)88 explicit Timer(StringRef Name, StringRef Description) { 89 init(Name, Description); 90 } Timer(StringRef Name,StringRef Description,TimerGroup & tg)91 Timer(StringRef Name, StringRef Description, TimerGroup &tg) { 92 init(Name, Description, tg); 93 } Timer(const Timer & RHS)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'. Timer()104 explicit Timer() {} 105 void init(StringRef Name, StringRef Description); 106 void init(StringRef Name, StringRef Description, TimerGroup &tg); 107 getName()108 const std::string &getName() const { return Name; } getDescription()109 const std::string &getDescription() const { return Description; } isInitialized()110 bool isInitialized() const { return TG != nullptr; } 111 112 /// Check if the timer is currently running. isRunning()113 bool isRunning() const { return Running; } 114 115 /// Check if startTimer() has ever been called on this timer. hasTriggered()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. getTotalTime()130 TimeRecord getTotalTime() const { return Time; } 131 132 private: 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. 140 class TimeRegion { 141 Timer *T; 142 TimeRegion(const TimeRegion &) = delete; 143 144 public: TimeRegion(Timer & t)145 explicit TimeRegion(Timer &t) : T(&t) { 146 T->startTimer(); 147 } TimeRegion(Timer * t)148 explicit TimeRegion(Timer *t) : T(t) { 149 if (T) T->startTimer(); 150 } ~TimeRegion()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. 160 struct 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. 170 class TimerGroup { 171 struct PrintRecord { 172 TimeRecord Time; 173 std::string Name; 174 std::string Description; 175 176 PrintRecord(const PrintRecord &Other) = default; PrintRecordPrintRecord177 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; 194 195 public: 196 explicit TimerGroup(StringRef Name, StringRef Description); 197 198 explicit TimerGroup(StringRef Name, StringRef Description, 199 const StringMap<TimeRecord> &Records); 200 201 ~TimerGroup(); 202 setName(StringRef NewName,StringRef NewDescription)203 void setName(StringRef NewName, StringRef NewDescription) { 204 Name.assign(NewName.begin(), NewName.end()); 205 Description.assign(NewDescription.begin(), NewDescription.end()); 206 } 207 208 /// Print any started timers in this group, optionally resetting timers after 209 /// printing them. 210 void print(raw_ostream &OS, bool ResetAfterPrint = false); 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(); 232 private: 233 friend class Timer; 234 friend void PrintStatisticsJSON(raw_ostream &OS); 235 void addTimer(Timer &T); 236 void removeTimer(Timer &T); 237 void prepareToPrintList(bool reset_time = false); 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