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/Compiler.h" 15 #include "llvm/Support/DataTypes.h" 16 #include "llvm/Support/Mutex.h" 17 #include <cassert> 18 #include <memory> 19 #include <string> 20 #include <vector> 21 22 namespace llvm { 23 24 class TimerGlobals; 25 class TimerGroup; 26 class raw_ostream; 27 28 class TimeRecord { 29 double WallTime = 0.0; ///< Wall clock time elapsed in seconds. 30 double UserTime = 0.0; ///< User time elapsed. 31 double SystemTime = 0.0; ///< System time elapsed. 32 ssize_t MemUsed = 0; ///< Memory allocated (in bytes). 33 uint64_t InstructionsExecuted = 0; ///< Number of instructions executed 34 public: 35 TimeRecord() = default; 36 37 /// Get the current time and memory usage. If Start is true we get the memory 38 /// usage before the time, otherwise we get time before memory usage. This 39 /// matters if the time to get the memory usage is significant and shouldn't 40 /// be counted as part of a duration. 41 LLVM_ABI static TimeRecord getCurrentTime(bool Start = true); 42 getProcessTime()43 double getProcessTime() const { return UserTime + SystemTime; } getUserTime()44 double getUserTime() const { return UserTime; } getSystemTime()45 double getSystemTime() const { return SystemTime; } getWallTime()46 double getWallTime() const { return WallTime; } getMemUsed()47 ssize_t getMemUsed() const { return MemUsed; } getInstructionsExecuted()48 uint64_t getInstructionsExecuted() const { return InstructionsExecuted; } 49 50 bool operator<(const TimeRecord &T) const { 51 // Sort by Wall Time elapsed, as it is the only thing really accurate 52 return WallTime < T.WallTime; 53 } 54 55 void operator+=(const TimeRecord &RHS) { 56 WallTime += RHS.WallTime; 57 UserTime += RHS.UserTime; 58 SystemTime += RHS.SystemTime; 59 MemUsed += RHS.MemUsed; 60 InstructionsExecuted += RHS.InstructionsExecuted; 61 } 62 void operator-=(const TimeRecord &RHS) { 63 WallTime -= RHS.WallTime; 64 UserTime -= RHS.UserTime; 65 SystemTime -= RHS.SystemTime; 66 MemUsed -= RHS.MemUsed; 67 InstructionsExecuted -= RHS.InstructionsExecuted; 68 } 69 70 /// Print the current time record to \p OS, with a breakdown showing 71 /// contributions to the \p Total time record. 72 LLVM_ABI void print(const TimeRecord &Total, raw_ostream &OS) const; 73 }; 74 75 /// This class is used to track the amount of time spent between invocations of 76 /// its startTimer()/stopTimer() methods. Given appropriate OS support it can 77 /// also keep track of the RSS of the program at various points. By default, 78 /// the Timer will print the amount of time it has captured to standard error 79 /// when the last timer is destroyed, otherwise it is printed when its 80 /// TimerGroup is destroyed. Timers do not print their information if they are 81 /// never started. 82 class Timer { 83 TimeRecord Time; ///< The total time captured. 84 TimeRecord StartTime; ///< The time startTimer() was last called. 85 std::string Name; ///< The name of this time variable. 86 std::string Description; ///< Description of this time variable. 87 bool Running = false; ///< Is the timer currently running? 88 bool Triggered = false; ///< Has the timer ever been triggered? 89 TimerGroup *TG = nullptr; ///< The TimerGroup this Timer is in. 90 91 Timer **Prev = nullptr; ///< Pointer to \p Next of previous timer in group. 92 Timer *Next = nullptr; ///< Next timer in the group. 93 public: Timer(StringRef TimerName,StringRef TimerDescription)94 explicit Timer(StringRef TimerName, StringRef TimerDescription) { 95 init(TimerName, TimerDescription); 96 } Timer(StringRef TimerName,StringRef TimerDescription,TimerGroup & tg)97 Timer(StringRef TimerName, StringRef TimerDescription, TimerGroup &tg) { 98 init(TimerName, TimerDescription, tg); 99 } Timer(const Timer & RHS)100 Timer(const Timer &RHS) { 101 assert(!RHS.TG && "Can only copy uninitialized timers"); 102 } 103 const Timer &operator=(const Timer &T) { 104 assert(!TG && !T.TG && "Can only assign uninit timers"); 105 return *this; 106 } 107 LLVM_ABI ~Timer(); 108 109 /// Create an uninitialized timer, client must use 'init'. 110 explicit Timer() = default; 111 LLVM_ABI void init(StringRef TimerName, StringRef TimerDescription); 112 LLVM_ABI void init(StringRef TimerName, StringRef TimerDescription, 113 TimerGroup &tg); 114 getName()115 const std::string &getName() const { return Name; } getDescription()116 const std::string &getDescription() const { return Description; } isInitialized()117 bool isInitialized() const { return TG != nullptr; } 118 119 /// Check if the timer is currently running. isRunning()120 bool isRunning() const { return Running; } 121 122 /// Check if startTimer() has ever been called on this timer. hasTriggered()123 bool hasTriggered() const { return Triggered; } 124 125 /// Start the timer running. Time between calls to startTimer/stopTimer is 126 /// counted by the Timer class. Note that these calls must be correctly 127 /// paired. 128 LLVM_ABI void startTimer(); 129 130 /// Stop the timer. 131 LLVM_ABI void stopTimer(); 132 133 /// Clear the timer state. 134 LLVM_ABI void clear(); 135 136 /// Stop the timer and start another timer. 137 LLVM_ABI void yieldTo(Timer &); 138 139 /// Return the duration for which this timer has been running. getTotalTime()140 TimeRecord getTotalTime() const { return Time; } 141 142 private: 143 friend class TimerGroup; 144 }; 145 146 /// The TimeRegion class is used as a helper class to call the startTimer() and 147 /// stopTimer() methods of the Timer class. When the object is constructed, it 148 /// starts the timer specified as its argument. When it is destroyed, it stops 149 /// the relevant timer. This makes it easy to time a region of code. 150 class TimeRegion { 151 Timer *T; 152 TimeRegion(const TimeRegion &) = delete; 153 154 public: TimeRegion(Timer & t)155 explicit TimeRegion(Timer &t) : T(&t) { 156 T->startTimer(); 157 } TimeRegion(Timer * t)158 explicit TimeRegion(Timer *t) : T(t) { 159 if (T) T->startTimer(); 160 } ~TimeRegion()161 ~TimeRegion() { 162 if (T) T->stopTimer(); 163 } 164 }; 165 166 /// This class is basically a combination of TimeRegion and Timer. It allows 167 /// you to declare a new timer, AND specify the region to time, all in one 168 /// statement. All timers with the same name are merged. This is primarily 169 /// used for debugging and for hunting performance problems. 170 struct NamedRegionTimer : public TimeRegion { 171 LLVM_ABI explicit NamedRegionTimer(StringRef Name, StringRef Description, 172 StringRef GroupName, 173 StringRef GroupDescription, 174 bool Enabled = true); 175 176 // Create or get a TimerGroup stored in the same global map owned by 177 // NamedRegionTimer. 178 LLVM_ABI static TimerGroup &getNamedTimerGroup(StringRef GroupName, 179 StringRef GroupDescription); 180 }; 181 182 /// The TimerGroup class is used to group together related timers into a single 183 /// report that is printed when the TimerGroup is destroyed. It is illegal to 184 /// destroy a TimerGroup object before all of the Timers in it are gone. A 185 /// TimerGroup can be specified for a newly created timer in its constructor. 186 class TimerGroup { 187 struct PrintRecord { 188 TimeRecord Time; 189 std::string Name; 190 std::string Description; 191 192 PrintRecord(const PrintRecord &Other) = default; 193 PrintRecord &operator=(const PrintRecord &Other) = default; PrintRecordPrintRecord194 PrintRecord(const TimeRecord &Time, const std::string &Name, 195 const std::string &Description) 196 : Time(Time), Name(Name), Description(Description) {} 197 198 bool operator <(const PrintRecord &Other) const { 199 return Time < Other.Time; 200 } 201 }; 202 std::string Name; 203 std::string Description; 204 Timer *FirstTimer = nullptr; ///< First timer in the group. 205 std::vector<PrintRecord> TimersToPrint; 206 207 TimerGroup **Prev; ///< Pointer to Next field of previous timergroup in list. 208 TimerGroup *Next; ///< Pointer to next timergroup in list. 209 TimerGroup(const TimerGroup &TG) = delete; 210 void operator=(const TimerGroup &TG) = delete; 211 212 friend class TimerGlobals; 213 explicit TimerGroup(StringRef Name, StringRef Description, 214 sys::SmartMutex<true> &lock); 215 216 public: 217 LLVM_ABI explicit TimerGroup(StringRef Name, StringRef Description); 218 219 LLVM_ABI explicit TimerGroup(StringRef Name, StringRef Description, 220 const StringMap<TimeRecord> &Records); 221 222 LLVM_ABI ~TimerGroup(); 223 setName(StringRef NewName,StringRef NewDescription)224 void setName(StringRef NewName, StringRef NewDescription) { 225 Name.assign(NewName.begin(), NewName.end()); 226 Description.assign(NewDescription.begin(), NewDescription.end()); 227 } 228 229 /// Print any started timers in this group, optionally resetting timers after 230 /// printing them. 231 LLVM_ABI void print(raw_ostream &OS, bool ResetAfterPrint = false); 232 233 /// Clear all timers in this group. 234 LLVM_ABI void clear(); 235 236 /// This static method prints all timers. 237 LLVM_ABI static void printAll(raw_ostream &OS); 238 239 /// Clear out all timers. This is mostly used to disable automatic 240 /// printing on shutdown, when timers have already been printed explicitly 241 /// using \c printAll or \c printJSONValues. 242 LLVM_ABI static void clearAll(); 243 244 LLVM_ABI const char *printJSONValues(raw_ostream &OS, const char *delim); 245 246 /// Prints all timers as JSON key/value pairs. 247 LLVM_ABI static const char *printAllJSONValues(raw_ostream &OS, 248 const char *delim); 249 250 /// Ensure global objects required for statistics printing are initialized. 251 /// This function is used by the Statistic code to ensure correct order of 252 /// global constructors and destructors. 253 LLVM_ABI static void constructForStatistics(); 254 255 /// This makes the timer globals unmanaged, and lets the user manage the 256 /// lifetime. 257 LLVM_ABI static void *acquireTimerGlobals(); 258 259 private: 260 friend class Timer; 261 LLVM_ABI friend void PrintStatisticsJSON(raw_ostream &OS); 262 void addTimer(Timer &T); 263 void removeTimer(Timer &T); 264 void prepareToPrintList(bool reset_time = false); 265 void PrintQueuedTimers(raw_ostream &OS); 266 void printJSONValue(raw_ostream &OS, const PrintRecord &R, 267 const char *suffix, double Value); 268 }; 269 270 } // end namespace llvm 271 272 #endif 273