• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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 #ifndef LLVM_SUPPORT_TIMER_H
11 #define LLVM_SUPPORT_TIMER_H
12 
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 public:
TimeRecord()32   TimeRecord() : WallTime(0), UserTime(0), SystemTime(0), MemUsed(0) {}
33 
34   /// getCurrentTime - Get the current time and memory usage.  If Start is true
35   /// we get the memory usage before the time, otherwise we get time before
36   /// memory usage.  This matters if the time to get the memory usage is
37   /// significant and shouldn't be counted as part of a duration.
38   static TimeRecord getCurrentTime(bool Start = true);
39 
getProcessTime()40   double getProcessTime() const { return UserTime+SystemTime; }
getUserTime()41   double getUserTime() const { return UserTime; }
getSystemTime()42   double getSystemTime() const { return SystemTime; }
getWallTime()43   double getWallTime() const { return WallTime; }
getMemUsed()44   ssize_t getMemUsed() const { return MemUsed; }
45 
46 
47   // operator< - Allow sorting.
48   bool operator<(const TimeRecord &T) const {
49     // Sort by Wall Time elapsed, as it is the only thing really accurate
50     return WallTime < T.WallTime;
51   }
52 
53   void operator+=(const TimeRecord &RHS) {
54     WallTime   += RHS.WallTime;
55     UserTime   += RHS.UserTime;
56     SystemTime += RHS.SystemTime;
57     MemUsed    += RHS.MemUsed;
58   }
59   void operator-=(const TimeRecord &RHS) {
60     WallTime   -= RHS.WallTime;
61     UserTime   -= RHS.UserTime;
62     SystemTime -= RHS.SystemTime;
63     MemUsed    -= RHS.MemUsed;
64   }
65 
66   /// print - Print the current timer to standard error, and reset the "Started"
67   /// flag.
68   void print(const TimeRecord &Total, raw_ostream &OS) const;
69 };
70 
71 /// Timer - This class is used to track the amount of time spent between
72 /// invocations of its startTimer()/stopTimer() methods.  Given appropriate OS
73 /// support it can also keep track of the RSS of the program at various points.
74 /// By default, the Timer will print the amount of time it has captured to
75 /// standard error when the last timer is destroyed, otherwise it is printed
76 /// when its TimerGroup is destroyed.  Timers do not print their information
77 /// if they are never started.
78 ///
79 class Timer {
80   TimeRecord Time;
81   std::string Name;      // The name of this time variable.
82   bool Started;          // Has this time variable ever been started?
83   TimerGroup *TG;        // The TimerGroup this Timer is in.
84 
85   Timer **Prev, *Next;   // Doubly linked list of timers in the group.
86 public:
Timer(StringRef N)87   explicit Timer(StringRef N) : TG(nullptr) { init(N); }
Timer(StringRef N,TimerGroup & tg)88   Timer(StringRef N, TimerGroup &tg) : TG(nullptr) { init(N, tg); }
Timer(const Timer & RHS)89   Timer(const Timer &RHS) : TG(nullptr) {
90     assert(!RHS.TG && "Can only copy uninitialized timers");
91   }
92   const Timer &operator=(const Timer &T) {
93     assert(!TG && !T.TG && "Can only assign uninit timers");
94     return *this;
95   }
96   ~Timer();
97 
98   // Create an uninitialized timer, client must use 'init'.
Timer()99   explicit Timer() : TG(nullptr) {}
100   void init(StringRef N);
101   void init(StringRef N, TimerGroup &tg);
102 
getName()103   const std::string &getName() const { return Name; }
isInitialized()104   bool isInitialized() const { return TG != nullptr; }
105 
106   /// startTimer - Start the timer running.  Time between calls to
107   /// startTimer/stopTimer is counted by the Timer class.  Note that these calls
108   /// must be correctly paired.
109   ///
110   void startTimer();
111 
112   /// stopTimer - Stop the timer.
113   ///
114   void stopTimer();
115 
116 private:
117   friend class TimerGroup;
118 };
119 
120 
121 /// The TimeRegion class is used as a helper class to call the startTimer() and
122 /// stopTimer() methods of the Timer class.  When the object is constructed, it
123 /// starts the timer specified as its argument.  When it is destroyed, it stops
124 /// the relevant timer.  This makes it easy to time a region of code.
125 ///
126 class TimeRegion {
127   Timer *T;
128   TimeRegion(const TimeRegion &) = delete;
129 public:
TimeRegion(Timer & t)130   explicit TimeRegion(Timer &t) : T(&t) {
131     T->startTimer();
132   }
TimeRegion(Timer * t)133   explicit TimeRegion(Timer *t) : T(t) {
134     if (T) T->startTimer();
135   }
~TimeRegion()136   ~TimeRegion() {
137     if (T) T->stopTimer();
138   }
139 };
140 
141 
142 /// NamedRegionTimer - This class is basically a combination of TimeRegion and
143 /// Timer.  It allows you to declare a new timer, AND specify the region to
144 /// time, all in one statement.  All timers with the same name are merged.  This
145 /// is primarily used for debugging and for hunting performance problems.
146 ///
147 struct NamedRegionTimer : public TimeRegion {
148   explicit NamedRegionTimer(StringRef Name,
149                             bool Enabled = true);
150   explicit NamedRegionTimer(StringRef Name, StringRef GroupName,
151                             bool Enabled = true);
152 };
153 
154 
155 /// The TimerGroup class is used to group together related timers into a single
156 /// report that is printed when the TimerGroup is destroyed.  It is illegal to
157 /// destroy a TimerGroup object before all of the Timers in it are gone.  A
158 /// TimerGroup can be specified for a newly created timer in its constructor.
159 ///
160 class TimerGroup {
161   std::string Name;
162   Timer *FirstTimer;   // First timer in the group.
163   std::vector<std::pair<TimeRecord, std::string> > TimersToPrint;
164 
165   TimerGroup **Prev, *Next; // Doubly linked list of TimerGroup's.
166   TimerGroup(const TimerGroup &TG) = delete;
167   void operator=(const TimerGroup &TG) = delete;
168 public:
169   explicit TimerGroup(StringRef name);
170   ~TimerGroup();
171 
setName(StringRef name)172   void setName(StringRef name) { Name.assign(name.begin(), name.end()); }
173 
174   /// print - Print any started timers in this group and zero them.
175   void print(raw_ostream &OS);
176 
177   /// printAll - This static method prints all timers and clears them all out.
178   static void printAll(raw_ostream &OS);
179 
180 private:
181   friend class Timer;
182   void addTimer(Timer &T);
183   void removeTimer(Timer &T);
184   void PrintQueuedTimers(raw_ostream &OS);
185 };
186 
187 } // End llvm namespace
188 
189 #endif
190