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 uint64_t InstructionsExecuted; ///< Number of instructions executed 32 public: 33 TimeRecord() 34 : WallTime(0), UserTime(0), SystemTime(0), MemUsed(0), 35 InstructionsExecuted(0) {} 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 static TimeRecord getCurrentTime(bool Start = true); 42 43 double getProcessTime() const { return UserTime + SystemTime; } 44 double getUserTime() const { return UserTime; } 45 double getSystemTime() const { return SystemTime; } 46 double getWallTime() const { return WallTime; } 47 ssize_t getMemUsed() const { return MemUsed; } 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 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: 94 explicit Timer(StringRef TimerName, StringRef TimerDescription) { 95 init(TimerName, TimerDescription); 96 } 97 Timer(StringRef TimerName, StringRef TimerDescription, TimerGroup &tg) { 98 init(TimerName, TimerDescription, tg); 99 } 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 ~Timer(); 108 109 /// Create an uninitialized timer, client must use 'init'. 110 explicit Timer() {} 111 void init(StringRef TimerName, StringRef TimerDescription); 112 void init(StringRef TimerName, StringRef TimerDescription, TimerGroup &tg); 113 114 const std::string &getName() const { return Name; } 115 const std::string &getDescription() const { return Description; } 116 bool isInitialized() const { return TG != nullptr; } 117 118 /// Check if the timer is currently running. 119 bool isRunning() const { return Running; } 120 121 /// Check if startTimer() has ever been called on this timer. 122 bool hasTriggered() const { return Triggered; } 123 124 /// Start the timer running. Time between calls to startTimer/stopTimer is 125 /// counted by the Timer class. Note that these calls must be correctly 126 /// paired. 127 void startTimer(); 128 129 /// Stop the timer. 130 void stopTimer(); 131 132 /// Clear the timer state. 133 void clear(); 134 135 /// Return the duration for which this timer has been running. 136 TimeRecord getTotalTime() const { return Time; } 137 138 private: 139 friend class TimerGroup; 140 }; 141 142 /// The TimeRegion class is used as a helper class to call the startTimer() and 143 /// stopTimer() methods of the Timer class. When the object is constructed, it 144 /// starts the timer specified as its argument. When it is destroyed, it stops 145 /// the relevant timer. This makes it easy to time a region of code. 146 class TimeRegion { 147 Timer *T; 148 TimeRegion(const TimeRegion &) = delete; 149 150 public: 151 explicit TimeRegion(Timer &t) : T(&t) { 152 T->startTimer(); 153 } 154 explicit TimeRegion(Timer *t) : T(t) { 155 if (T) T->startTimer(); 156 } 157 ~TimeRegion() { 158 if (T) T->stopTimer(); 159 } 160 }; 161 162 /// This class is basically a combination of TimeRegion and Timer. It allows 163 /// you to declare a new timer, AND specify the region to time, all in one 164 /// statement. All timers with the same name are merged. This is primarily 165 /// used for debugging and for hunting performance problems. 166 struct NamedRegionTimer : public TimeRegion { 167 explicit NamedRegionTimer(StringRef Name, StringRef Description, 168 StringRef GroupName, 169 StringRef GroupDescription, bool Enabled = true); 170 }; 171 172 /// The TimerGroup class is used to group together related timers into a single 173 /// report that is printed when the TimerGroup is destroyed. It is illegal to 174 /// destroy a TimerGroup object before all of the Timers in it are gone. A 175 /// TimerGroup can be specified for a newly created timer in its constructor. 176 class TimerGroup { 177 struct PrintRecord { 178 TimeRecord Time; 179 std::string Name; 180 std::string Description; 181 182 PrintRecord(const PrintRecord &Other) = default; 183 PrintRecord &operator=(const PrintRecord &Other) = default; 184 PrintRecord(const TimeRecord &Time, const std::string &Name, 185 const std::string &Description) 186 : Time(Time), Name(Name), Description(Description) {} 187 188 bool operator <(const PrintRecord &Other) const { 189 return Time < Other.Time; 190 } 191 }; 192 std::string Name; 193 std::string Description; 194 Timer *FirstTimer = nullptr; ///< First timer in the group. 195 std::vector<PrintRecord> TimersToPrint; 196 197 TimerGroup **Prev; ///< Pointer to Next field of previous timergroup in list. 198 TimerGroup *Next; ///< Pointer to next timergroup in list. 199 TimerGroup(const TimerGroup &TG) = delete; 200 void operator=(const TimerGroup &TG) = delete; 201 202 public: 203 explicit TimerGroup(StringRef Name, StringRef Description); 204 205 explicit TimerGroup(StringRef Name, StringRef Description, 206 const StringMap<TimeRecord> &Records); 207 208 ~TimerGroup(); 209 210 void setName(StringRef NewName, StringRef NewDescription) { 211 Name.assign(NewName.begin(), NewName.end()); 212 Description.assign(NewDescription.begin(), NewDescription.end()); 213 } 214 215 /// Print any started timers in this group, optionally resetting timers after 216 /// printing them. 217 void print(raw_ostream &OS, bool ResetAfterPrint = false); 218 219 /// Clear all timers in this group. 220 void clear(); 221 222 /// This static method prints all timers. 223 static void printAll(raw_ostream &OS); 224 225 /// Clear out all timers. This is mostly used to disable automatic 226 /// printing on shutdown, when timers have already been printed explicitly 227 /// using \c printAll or \c printJSONValues. 228 static void clearAll(); 229 230 const char *printJSONValues(raw_ostream &OS, const char *delim); 231 232 /// Prints all timers as JSON key/value pairs. 233 static const char *printAllJSONValues(raw_ostream &OS, const char *delim); 234 235 /// Ensure global timer group lists are initialized. This function is mostly 236 /// used by the Statistic code to influence the construction and destruction 237 /// order of the global timer lists. 238 static void ConstructTimerLists(); 239 240 /// This makes the default group unmanaged, and lets the user manage the 241 /// group's lifetime. 242 static std::unique_ptr<TimerGroup> aquireDefaultGroup(); 243 244 private: 245 friend class Timer; 246 friend void PrintStatisticsJSON(raw_ostream &OS); 247 void addTimer(Timer &T); 248 void removeTimer(Timer &T); 249 void prepareToPrintList(bool reset_time = false); 250 void PrintQueuedTimers(raw_ostream &OS); 251 void printJSONValue(raw_ostream &OS, const PrintRecord &R, 252 const char *suffix, double Value); 253 }; 254 255 } // end namespace llvm 256 257 #endif 258