Timer.h revision 360784
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 20namespace llvm { 21 22class Timer; 23class TimerGroup; 24class raw_ostream; 25 26class 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). 31public: 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 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 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. 76class 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 = false; ///< Is the timer currently running? 82 bool Triggered = false; ///< Has the timer ever been triggered? 83 TimerGroup *TG = nullptr; ///< The TimerGroup this Timer is in. 84 85 Timer **Prev = nullptr; ///< Pointer to \p Next of previous timer in group. 86 Timer *Next = nullptr; ///< Next timer in the group. 87public: 88 explicit Timer(StringRef TimerName, StringRef TimerDescription) { 89 init(TimerName, TimerDescription); 90 } 91 Timer(StringRef TimerName, StringRef TimerDescription, TimerGroup &tg) { 92 init(TimerName, TimerDescription, tg); 93 } 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'. 104 explicit Timer() {} 105 void init(StringRef TimerName, StringRef TimerDescription); 106 void init(StringRef TimerName, StringRef TimerDescription, TimerGroup &tg); 107 108 const std::string &getName() const { return Name; } 109 const std::string &getDescription() const { return Description; } 110 bool isInitialized() const { return TG != nullptr; } 111 112 /// Check if the timer is currently running. 113 bool isRunning() const { return Running; } 114 115 /// Check if startTimer() has ever been called on this timer. 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. 130 TimeRecord getTotalTime() const { return Time; } 131 132private: 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. 140class TimeRegion { 141 Timer *T; 142 TimeRegion(const TimeRegion &) = delete; 143 144public: 145 explicit TimeRegion(Timer &t) : T(&t) { 146 T->startTimer(); 147 } 148 explicit TimeRegion(Timer *t) : T(t) { 149 if (T) T->startTimer(); 150 } 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. 160struct 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. 170class TimerGroup { 171 struct PrintRecord { 172 TimeRecord Time; 173 std::string Name; 174 std::string Description; 175 176 PrintRecord(const PrintRecord &Other) = default; 177 PrintRecord &operator=(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, optionally resetting timers after 210 /// printing them. 211 void print(raw_ostream &OS, bool ResetAfterPrint = false); 212 213 /// Clear all timers in this group. 214 void clear(); 215 216 /// This static method prints all timers. 217 static void printAll(raw_ostream &OS); 218 219 /// Clear out all timers. This is mostly used to disable automatic 220 /// printing on shutdown, when timers have already been printed explicitly 221 /// using \c printAll or \c printJSONValues. 222 static void clearAll(); 223 224 const char *printJSONValues(raw_ostream &OS, const char *delim); 225 226 /// Prints all timers as JSON key/value pairs. 227 static const char *printAllJSONValues(raw_ostream &OS, const char *delim); 228 229 /// Ensure global timer group lists are initialized. This function is mostly 230 /// used by the Statistic code to influence the construction and destruction 231 /// order of the global timer lists. 232 static void ConstructTimerLists(); 233 234 /// This makes the default group unmanaged, and lets the user manage the 235 /// group's lifetime. 236 static std::unique_ptr<TimerGroup> aquireDefaultGroup(); 237 238private: 239 friend class Timer; 240 friend void PrintStatisticsJSON(raw_ostream &OS); 241 void addTimer(Timer &T); 242 void removeTimer(Timer &T); 243 void prepareToPrintList(bool reset_time = false); 244 void PrintQueuedTimers(raw_ostream &OS); 245 void printJSONValue(raw_ostream &OS, const PrintRecord &R, 246 const char *suffix, double Value); 247}; 248 249} // end namespace llvm 250 251#endif 252