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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 "llvm/ADT/StringRef.h"
20 #include <cassert>
21 #include <string>
22 #include <vector>
23 #include <utility>
24 
25 namespace llvm {
26 
27 class Timer;
28 class TimerGroup;
29 class raw_ostream;
30 
31 class TimeRecord {
32   double WallTime;       // Wall clock time elapsed in seconds
33   double UserTime;       // User time elapsed
34   double SystemTime;     // System time elapsed
35   ssize_t MemUsed;       // Memory allocated (in bytes)
36 public:
TimeRecord()37   TimeRecord() : WallTime(0), UserTime(0), SystemTime(0), MemUsed(0) {}
38 
39   /// getCurrentTime - Get the current time and memory usage.  If Start is true
40   /// we get the memory usage before the time, otherwise we get time before
41   /// memory usage.  This matters if the time to get the memory usage is
42   /// significant and shouldn't be counted as part of a duration.
43   static TimeRecord getCurrentTime(bool Start = true);
44 
getProcessTime()45   double getProcessTime() const { return UserTime+SystemTime; }
getUserTime()46   double getUserTime() const { return UserTime; }
getSystemTime()47   double getSystemTime() const { return SystemTime; }
getWallTime()48   double getWallTime() const { return WallTime; }
getMemUsed()49   ssize_t getMemUsed() const { return MemUsed; }
50 
51 
52   // operator< - Allow sorting.
53   bool operator<(const TimeRecord &T) const {
54     // Sort by Wall Time elapsed, as it is the only thing really accurate
55     return WallTime < T.WallTime;
56   }
57 
58   void operator+=(const TimeRecord &RHS) {
59     WallTime   += RHS.WallTime;
60     UserTime   += RHS.UserTime;
61     SystemTime += RHS.SystemTime;
62     MemUsed    += RHS.MemUsed;
63   }
64   void operator-=(const TimeRecord &RHS) {
65     WallTime   -= RHS.WallTime;
66     UserTime   -= RHS.UserTime;
67     SystemTime -= RHS.SystemTime;
68     MemUsed    -= RHS.MemUsed;
69   }
70 
71   /// print - Print the current timer to standard error, and reset the "Started"
72   /// flag.
73   void print(const TimeRecord &Total, raw_ostream &OS) const;
74 };
75 
76 /// Timer - This class is used to track the amount of time spent between
77 /// invocations of its startTimer()/stopTimer() methods.  Given appropriate OS
78 /// support it can also keep track of the RSS of the program at various points.
79 /// By default, the Timer will print the amount of time it has captured to
80 /// standard error when the laster timer is destroyed, otherwise it is printed
81 /// when its TimerGroup is destroyed.  Timers do not print their information
82 /// if they are never started.
83 ///
84 class Timer {
85   TimeRecord Time;
86   std::string Name;      // The name of this time variable.
87   bool Started;          // Has this time variable ever been started?
88   TimerGroup *TG;        // The TimerGroup this Timer is in.
89 
90   Timer **Prev, *Next;   // Doubly linked list of timers in the group.
91 public:
Timer(StringRef N)92   explicit Timer(StringRef N) : TG(0) { init(N); }
Timer(StringRef N,TimerGroup & tg)93   Timer(StringRef N, TimerGroup &tg) : TG(0) { init(N, tg); }
Timer(const Timer & RHS)94   Timer(const Timer &RHS) : TG(0) {
95     assert(RHS.TG == 0 && "Can only copy uninitialized timers");
96   }
97   const Timer &operator=(const Timer &T) {
98     assert(TG == 0 && T.TG == 0 && "Can only assign uninit timers");
99     return *this;
100   }
101   ~Timer();
102 
103   // Create an uninitialized timer, client must use 'init'.
Timer()104   explicit Timer() : TG(0) {}
105   void init(StringRef N);
106   void init(StringRef N, TimerGroup &tg);
107 
getName()108   const std::string &getName() const { return Name; }
isInitialized()109   bool isInitialized() const { return TG != 0; }
110 
111   /// startTimer - Start the timer running.  Time between calls to
112   /// startTimer/stopTimer is counted by the Timer class.  Note that these calls
113   /// must be correctly paired.
114   ///
115   void startTimer();
116 
117   /// stopTimer - Stop the timer.
118   ///
119   void stopTimer();
120 
121 private:
122   friend class TimerGroup;
123 };
124 
125 
126 /// The TimeRegion class is used as a helper class to call the startTimer() and
127 /// stopTimer() methods of the Timer class.  When the object is constructed, it
128 /// starts the timer specified as it's argument.  When it is destroyed, it stops
129 /// the relevant timer.  This makes it easy to time a region of code.
130 ///
131 class TimeRegion {
132   Timer *T;
133   TimeRegion(const TimeRegion &); // DO NOT IMPLEMENT
134 public:
TimeRegion(Timer & t)135   explicit TimeRegion(Timer &t) : T(&t) {
136     T->startTimer();
137   }
TimeRegion(Timer * t)138   explicit TimeRegion(Timer *t) : T(t) {
139     if (T) T->startTimer();
140   }
~TimeRegion()141   ~TimeRegion() {
142     if (T) T->stopTimer();
143   }
144 };
145 
146 
147 /// NamedRegionTimer - This class is basically a combination of TimeRegion and
148 /// Timer.  It allows you to declare a new timer, AND specify the region to
149 /// time, all in one statement.  All timers with the same name are merged.  This
150 /// is primarily used for debugging and for hunting performance problems.
151 ///
152 struct NamedRegionTimer : public TimeRegion {
153   explicit NamedRegionTimer(StringRef Name,
154                             bool Enabled = true);
155   explicit NamedRegionTimer(StringRef Name, StringRef GroupName,
156                             bool Enabled = true);
157 };
158 
159 
160 /// The TimerGroup class is used to group together related timers into a single
161 /// report that is printed when the TimerGroup is destroyed.  It is illegal to
162 /// destroy a TimerGroup object before all of the Timers in it are gone.  A
163 /// TimerGroup can be specified for a newly created timer in its constructor.
164 ///
165 class TimerGroup {
166   std::string Name;
167   Timer *FirstTimer;   // First timer in the group.
168   std::vector<std::pair<TimeRecord, std::string> > TimersToPrint;
169 
170   TimerGroup **Prev, *Next; // Doubly linked list of TimerGroup's.
171   TimerGroup(const TimerGroup &TG);      // DO NOT IMPLEMENT
172   void operator=(const TimerGroup &TG);  // DO NOT IMPLEMENT
173 public:
174   explicit TimerGroup(StringRef name);
175   ~TimerGroup();
176 
setName(StringRef name)177   void setName(StringRef name) { Name.assign(name.begin(), name.end()); }
178 
179   /// print - Print any started timers in this group and zero them.
180   void print(raw_ostream &OS);
181 
182   /// printAll - This static method prints all timers and clears them all out.
183   static void printAll(raw_ostream &OS);
184 
185 private:
186   friend class Timer;
187   void addTimer(Timer &T);
188   void removeTimer(Timer &T);
189   void PrintQueuedTimers(raw_ostream &OS);
190 };
191 
192 } // End llvm namespace
193 
194 #endif
195