Timer.h revision 94f9c7dc97bc586e01c101e9fcfeb93c2fb4bd87
1//===-- llvm/Support/Timer.h - Interval Timing Support ----------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file defines three classes: Timer, TimeRegion, and TimerGroup, 11// documented below. 12// 13//===----------------------------------------------------------------------===// 14 15#ifndef LLVM_SUPPORT_TIMER_H 16#define LLVM_SUPPORT_TIMER_H 17 18#include "llvm/Support/DataTypes.h" 19#include <string> 20#include <vector> 21#include <iosfwd> 22#include <cassert> 23 24namespace llvm { 25 26class TimerGroup; 27 28/// Timer - This class is used to track the amount of time spent between 29/// invocations of it's startTimer()/stopTimer() methods. Given appropriate OS 30/// support it can also keep track of the RSS of the program at various points. 31/// By default, the Timer will print the amount of time it has captured to 32/// standard error when the laster timer is destroyed, otherwise it is printed 33/// when its TimerGroup is destroyed. Timers do not print their information 34/// if they are never started. 35/// 36class Timer { 37 double Elapsed; // Wall clock time elapsed in seconds 38 double UserTime; // User time elapsed 39 double SystemTime; // System time elapsed 40 ssize_t MemUsed; // Memory allocated (in bytes) 41 size_t PeakMem; // Peak memory used 42 size_t PeakMemBase; // Temporary for peak calculation... 43 std::string Name; // The name of this time variable 44 bool Started; // Has this time variable ever been started? 45 TimerGroup *TG; // The TimerGroup this Timer is in. 46public: 47 Timer(const std::string &N); 48 Timer(const std::string &N, TimerGroup &tg); 49 Timer(const Timer &T); 50 ~Timer(); 51 52 double getProcessTime() const { return UserTime+SystemTime; } 53 double getWallTime() const { return Elapsed; } 54 ssize_t getMemUsed() const { return MemUsed; } 55 size_t getPeakMem() const { return PeakMem; } 56 std::string getName() const { return Name; } 57 58 const Timer &operator=(const Timer &T) { 59 Elapsed = T.Elapsed; 60 UserTime = T.UserTime; 61 SystemTime = T.SystemTime; 62 MemUsed = T.MemUsed; 63 PeakMem = T.PeakMem; 64 PeakMemBase = T.PeakMemBase; 65 Name = T.Name; 66 Started = T.Started; 67 assert(TG == T.TG && "Can only assign timers in the same TimerGroup!"); 68 return *this; 69 } 70 71 // operator< - Allow sorting... 72 bool operator<(const Timer &T) const { 73 // Sort by Wall Time elapsed, as it is the only thing really accurate 74 return Elapsed < T.Elapsed; 75 } 76 bool operator>(const Timer &T) const { return T.operator<(*this); } 77 78 /// startTimer - Start the timer running. Time between calls to 79 /// startTimer/stopTimer is counted by the Timer class. Note that these calls 80 /// must be correctly paired. 81 /// 82 void startTimer(); 83 84 /// stopTimer - Stop the timer. 85 /// 86 void stopTimer(); 87 88 /// addPeakMemoryMeasurement - This method should be called whenever memory 89 /// usage needs to be checked. It adds a peak memory measurement to the 90 /// currently active timers, which will be printed when the timer group prints 91 /// 92 static void addPeakMemoryMeasurement(); 93 94 /// print - Print the current timer to standard error, and reset the "Started" 95 /// flag. 96 void print(const Timer &Total, std::ostream &OS); 97 98private: 99 friend class TimerGroup; 100 101 // Copy ctor, initialize with no TG member. 102 Timer(bool, const Timer &T); 103 104 /// sum - Add the time accumulated in the specified timer into this timer. 105 /// 106 void sum(const Timer &T); 107}; 108 109 110/// The TimeRegion class is used as a helper class to call the startTimer() and 111/// stopTimer() methods of the Timer class. When the object is constructed, it 112/// starts the timer specified as it's argument. When it is destroyed, it stops 113/// the relevant timer. This makes it easy to time a region of code. 114/// 115class TimeRegion { 116 Timer &T; 117 TimeRegion(const TimeRegion &); // DO NOT IMPLEMENT 118public: 119 TimeRegion(Timer &t) : T(t) { 120 T.startTimer(); 121 } 122 ~TimeRegion() { 123 T.stopTimer(); 124 } 125}; 126 127 128/// NamedRegionTimer - This class is basically a combination of TimeRegion and 129/// Timer. It allows you to declare a new timer, AND specify the region to 130/// time, all in one statement. All timers with the same name are merged. This 131/// is primarily used for debugging and for hunting performance problems. 132/// 133struct NamedRegionTimer : public TimeRegion { 134 NamedRegionTimer(const std::string &Name); 135}; 136 137 138/// The TimerGroup class is used to group together related timers into a single 139/// report that is printed when the TimerGroup is destroyed. It is illegal to 140/// destroy a TimerGroup object before all of the Timers in it are gone. A 141/// TimerGroup can be specified for a newly created timer in its constructor. 142/// 143class TimerGroup { 144 std::string Name; 145 unsigned NumTimers; 146 std::vector<Timer> TimersToPrint; 147public: 148 TimerGroup(const std::string &name) : Name(name), NumTimers(0) {} 149 ~TimerGroup() { 150 assert(NumTimers == 0 && 151 "TimerGroup destroyed before all contained timers!"); 152 } 153 154private: 155 friend class Timer; 156 void addTimer() { ++NumTimers; } 157 void removeTimer(); 158 void addTimerToPrint(const Timer &T) { 159 TimersToPrint.push_back(Timer(true, T)); 160 } 161}; 162 163} // End llvm namespace 164 165#endif 166