LLVM API Documentation
00001 //===-- llvm/Support/Timer.h - Interval Timing Support ----------*- C++ -*-===// 00002 // 00003 // The LLVM Compiler Infrastructure 00004 // 00005 // This file was developed by the LLVM research group and is distributed under 00006 // the University of Illinois Open Source License. See LICENSE.TXT for details. 00007 // 00008 //===----------------------------------------------------------------------===// 00009 // 00010 // This file defines three classes: Timer, TimeRegion, and TimerGroup, 00011 // documented below. 00012 // 00013 //===----------------------------------------------------------------------===// 00014 00015 #ifndef LLVM_SUPPORT_TIMER_H 00016 #define LLVM_SUPPORT_TIMER_H 00017 00018 #include "llvm/Support/DataTypes.h" 00019 #include <string> 00020 #include <vector> 00021 #include <iosfwd> 00022 #include <cassert> 00023 00024 namespace llvm { 00025 00026 class TimerGroup; 00027 00028 /// Timer - This class is used to track the amount of time spent between 00029 /// invocations of it's startTimer()/stopTimer() methods. Given appropriate OS 00030 /// support it can also keep track of the RSS of the program at various points. 00031 /// By default, the Timer will print the amount of time it has captured to 00032 /// standard error when the laster timer is destroyed, otherwise it is printed 00033 /// when it's TimerGroup is destroyed. Timer's do not print their information 00034 /// if they are never started. 00035 /// 00036 class Timer { 00037 double Elapsed; // Wall clock time elapsed in seconds 00038 double UserTime; // User time elapsed 00039 double SystemTime; // System time elapsed 00040 ssize_t MemUsed; // Memory allocated (in bytes) 00041 size_t PeakMem; // Peak memory used 00042 size_t PeakMemBase; // Temporary for peak calculation... 00043 std::string Name; // The name of this time variable 00044 bool Started; // Has this time variable ever been started? 00045 TimerGroup *TG; // The TimerGroup this Timer is in. 00046 public: 00047 Timer(const std::string &N); 00048 Timer(const std::string &N, TimerGroup &tg); 00049 Timer(const Timer &T); 00050 ~Timer(); 00051 00052 double getProcessTime() const { return UserTime+SystemTime; } 00053 double getWallTime() const { return Elapsed; } 00054 ssize_t getMemUsed() const { return MemUsed; } 00055 size_t getPeakMem() const { return PeakMem; } 00056 std::string getName() const { return Name; } 00057 00058 const Timer &operator=(const Timer &T) { 00059 Elapsed = T.Elapsed; 00060 UserTime = T.UserTime; 00061 SystemTime = T.SystemTime; 00062 MemUsed = T.MemUsed; 00063 PeakMem = T.PeakMem; 00064 PeakMemBase = T.PeakMemBase; 00065 Name = T.Name; 00066 Started = T.Started; 00067 assert(TG == T.TG && "Can only assign timers in the same TimerGroup!"); 00068 return *this; 00069 } 00070 00071 // operator< - Allow sorting... 00072 bool operator<(const Timer &T) const { 00073 // Sort by Wall Time elapsed, as it is the only thing really accurate 00074 return Elapsed < T.Elapsed; 00075 } 00076 bool operator>(const Timer &T) const { return T.operator<(*this); } 00077 00078 /// startTimer - Start the timer running. Time between calls to 00079 /// startTimer/stopTimer is counted by the Timer class. Note that these calls 00080 /// must be correctly paired. 00081 /// 00082 void startTimer(); 00083 00084 /// stopTimer - Stop the timer. 00085 /// 00086 void stopTimer(); 00087 00088 /// addPeakMemoryMeasurement - This method should be called whenever memory 00089 /// usage needs to be checked. It adds a peak memory measurement to the 00090 /// currently active timers, which will be printed when the timer group prints 00091 /// 00092 static void addPeakMemoryMeasurement(); 00093 00094 /// print - Print the current timer to standard error, and reset the "Started" 00095 /// flag. 00096 void print(const Timer &Total, std::ostream &OS); 00097 00098 private: 00099 friend class TimerGroup; 00100 00101 // Copy ctor, initialize with no TG member. 00102 Timer(bool, const Timer &T); 00103 00104 /// sum - Add the time accumulated in the specified timer into this timer. 00105 /// 00106 void sum(const Timer &T); 00107 }; 00108 00109 00110 /// The TimeRegion class is used as a helper class to call the startTimer() and 00111 /// stopTimer() methods of the Timer class. When the object is constructed, it 00112 /// starts the timer specified as it's argument. When it is destroyed, it stops 00113 /// the relevant timer. This makes it easy to time a region of code. 00114 /// 00115 class TimeRegion { 00116 Timer &T; 00117 TimeRegion(const TimeRegion &); // DO NOT IMPLEMENT 00118 public: 00119 TimeRegion(Timer &t) : T(t) { 00120 T.startTimer(); 00121 } 00122 ~TimeRegion() { 00123 T.stopTimer(); 00124 } 00125 }; 00126 00127 00128 /// NamedRegionTimer - This class is basically a combination of TimeRegion and 00129 /// Timer. It allows you to declare a new timer, AND specify the region to 00130 /// time, all in one statement. All timers with the same name are merged. This 00131 /// is primarily used for debugging and for hunting performance problems. 00132 /// 00133 struct NamedRegionTimer : public TimeRegion { 00134 NamedRegionTimer(const std::string &Name); 00135 }; 00136 00137 00138 /// The TimerGroup class is used to group together related timers into a single 00139 /// report that is printed when the TimerGroup is destroyed. It is illegal to 00140 /// destroy a TimerGroup object before all of the Timers in it are gone. A 00141 /// TimerGroup can be specified for a newly created timer in its constructor. 00142 /// 00143 class TimerGroup { 00144 std::string Name; 00145 unsigned NumTimers; 00146 std::vector<Timer> TimersToPrint; 00147 public: 00148 TimerGroup(const std::string &name) : Name(name), NumTimers(0) {} 00149 ~TimerGroup() { 00150 assert(NumTimers == 0 && 00151 "TimerGroup destroyed before all contained timers!"); 00152 } 00153 00154 private: 00155 friend class Timer; 00156 void addTimer() { ++NumTimers; } 00157 void removeTimer(); 00158 void addTimerToPrint(const Timer &T) { 00159 TimersToPrint.push_back(Timer(true, T)); 00160 } 00161 }; 00162 00163 } // End llvm namespace 00164 00165 #endif