LLVM API Documentation

Timer.cpp
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00001 //===-- Timer.cpp - Interval Timing Support -------------------------------===//
00002 //
00003 //                     The LLVM Compiler Infrastructure
00004 //
00005 // This file is distributed under the University of Illinois Open Source
00006 // License. See LICENSE.TXT for details.
00007 //
00008 //===----------------------------------------------------------------------===//
00009 //
00010 // Interval Timing implementation.
00011 //
00012 //===----------------------------------------------------------------------===//
00013 
00014 #include "llvm/Support/Timer.h"
00015 #include "llvm/ADT/StringMap.h"
00016 #include "llvm/Support/CommandLine.h"
00017 #include "llvm/Support/Debug.h"
00018 #include "llvm/Support/FileSystem.h"
00019 #include "llvm/Support/Format.h"
00020 #include "llvm/Support/ManagedStatic.h"
00021 #include "llvm/Support/Mutex.h"
00022 #include "llvm/Support/MutexGuard.h"
00023 #include "llvm/Support/Process.h"
00024 #include "llvm/Support/raw_ostream.h"
00025 using namespace llvm;
00026 
00027 // CreateInfoOutputFile - Return a file stream to print our output on.
00028 namespace llvm { extern raw_ostream *CreateInfoOutputFile(); }
00029 
00030 // getLibSupportInfoOutputFilename - This ugly hack is brought to you courtesy
00031 // of constructor/destructor ordering being unspecified by C++.  Basically the
00032 // problem is that a Statistic object gets destroyed, which ends up calling
00033 // 'GetLibSupportInfoOutputFile()' (below), which calls this function.
00034 // LibSupportInfoOutputFilename used to be a global variable, but sometimes it
00035 // would get destroyed before the Statistic, causing havoc to ensue.  We "fix"
00036 // this by creating the string the first time it is needed and never destroying
00037 // it.
00038 static ManagedStatic<std::string> LibSupportInfoOutputFilename;
00039 static std::string &getLibSupportInfoOutputFilename() {
00040   return *LibSupportInfoOutputFilename;
00041 }
00042 
00043 static ManagedStatic<sys::SmartMutex<true> > TimerLock;
00044 
00045 namespace {
00046   static cl::opt<bool>
00047   TrackSpace("track-memory", cl::desc("Enable -time-passes memory "
00048                                       "tracking (this may be slow)"),
00049              cl::Hidden);
00050 
00051   static cl::opt<std::string, true>
00052   InfoOutputFilename("info-output-file", cl::value_desc("filename"),
00053                      cl::desc("File to append -stats and -timer output to"),
00054                    cl::Hidden, cl::location(getLibSupportInfoOutputFilename()));
00055 }
00056 
00057 // CreateInfoOutputFile - Return a file stream to print our output on.
00058 raw_ostream *llvm::CreateInfoOutputFile() {
00059   const std::string &OutputFilename = getLibSupportInfoOutputFilename();
00060   if (OutputFilename.empty())
00061     return new raw_fd_ostream(2, false); // stderr.
00062   if (OutputFilename == "-")
00063     return new raw_fd_ostream(1, false); // stdout.
00064   
00065   // Append mode is used because the info output file is opened and closed
00066   // each time -stats or -time-passes wants to print output to it. To
00067   // compensate for this, the test-suite Makefiles have code to delete the
00068   // info output file before running commands which write to it.
00069   std::string Error;
00070   raw_ostream *Result = new raw_fd_ostream(
00071       OutputFilename.c_str(), Error, sys::fs::F_Append | sys::fs::F_Text);
00072   if (Error.empty())
00073     return Result;
00074   
00075   errs() << "Error opening info-output-file '"
00076     << OutputFilename << " for appending!\n";
00077   delete Result;
00078   return new raw_fd_ostream(2, false); // stderr.
00079 }
00080 
00081 
00082 static TimerGroup *DefaultTimerGroup = nullptr;
00083 static TimerGroup *getDefaultTimerGroup() {
00084   TimerGroup *tmp = DefaultTimerGroup;
00085   sys::MemoryFence();
00086   if (tmp) return tmp;
00087   
00088   sys::SmartScopedLock<true> Lock(*TimerLock);
00089   tmp = DefaultTimerGroup;
00090   if (!tmp) {
00091     tmp = new TimerGroup("Miscellaneous Ungrouped Timers");
00092     sys::MemoryFence();
00093     DefaultTimerGroup = tmp;
00094   }
00095 
00096   return tmp;
00097 }
00098 
00099 //===----------------------------------------------------------------------===//
00100 // Timer Implementation
00101 //===----------------------------------------------------------------------===//
00102 
00103 void Timer::init(StringRef N) {
00104   assert(!TG && "Timer already initialized");
00105   Name.assign(N.begin(), N.end());
00106   Started = false;
00107   TG = getDefaultTimerGroup();
00108   TG->addTimer(*this);
00109 }
00110 
00111 void Timer::init(StringRef N, TimerGroup &tg) {
00112   assert(!TG && "Timer already initialized");
00113   Name.assign(N.begin(), N.end());
00114   Started = false;
00115   TG = &tg;
00116   TG->addTimer(*this);
00117 }
00118 
00119 Timer::~Timer() {
00120   if (!TG) return;  // Never initialized, or already cleared.
00121   TG->removeTimer(*this);
00122 }
00123 
00124 static inline size_t getMemUsage() {
00125   if (!TrackSpace) return 0;
00126   return sys::Process::GetMallocUsage();
00127 }
00128 
00129 TimeRecord TimeRecord::getCurrentTime(bool Start) {
00130   TimeRecord Result;
00131   sys::TimeValue now(0,0), user(0,0), sys(0,0);
00132   
00133   if (Start) {
00134     Result.MemUsed = getMemUsage();
00135     sys::Process::GetTimeUsage(now, user, sys);
00136   } else {
00137     sys::Process::GetTimeUsage(now, user, sys);
00138     Result.MemUsed = getMemUsage();
00139   }
00140 
00141   Result.WallTime   =  now.seconds() +  now.microseconds() / 1000000.0;
00142   Result.UserTime   = user.seconds() + user.microseconds() / 1000000.0;
00143   Result.SystemTime =  sys.seconds() +  sys.microseconds() / 1000000.0;
00144   return Result;
00145 }
00146 
00147 static ManagedStatic<std::vector<Timer*> > ActiveTimers;
00148 
00149 void Timer::startTimer() {
00150   Started = true;
00151   ActiveTimers->push_back(this);
00152   Time -= TimeRecord::getCurrentTime(true);
00153 }
00154 
00155 void Timer::stopTimer() {
00156   Time += TimeRecord::getCurrentTime(false);
00157 
00158   if (ActiveTimers->back() == this) {
00159     ActiveTimers->pop_back();
00160   } else {
00161     std::vector<Timer*>::iterator I =
00162       std::find(ActiveTimers->begin(), ActiveTimers->end(), this);
00163     assert(I != ActiveTimers->end() && "stop but no startTimer?");
00164     ActiveTimers->erase(I);
00165   }
00166 }
00167 
00168 static void printVal(double Val, double Total, raw_ostream &OS) {
00169   if (Total < 1e-7)   // Avoid dividing by zero.
00170     OS << "        -----     ";
00171   else
00172     OS << format("  %7.4f (%5.1f%%)", Val, Val*100/Total);
00173 }
00174 
00175 void TimeRecord::print(const TimeRecord &Total, raw_ostream &OS) const {
00176   if (Total.getUserTime())
00177     printVal(getUserTime(), Total.getUserTime(), OS);
00178   if (Total.getSystemTime())
00179     printVal(getSystemTime(), Total.getSystemTime(), OS);
00180   if (Total.getProcessTime())
00181     printVal(getProcessTime(), Total.getProcessTime(), OS);
00182   printVal(getWallTime(), Total.getWallTime(), OS);
00183   
00184   OS << "  ";
00185   
00186   if (Total.getMemUsed())
00187     OS << format("%9" PRId64 "  ", (int64_t)getMemUsed());
00188 }
00189 
00190 
00191 //===----------------------------------------------------------------------===//
00192 //   NamedRegionTimer Implementation
00193 //===----------------------------------------------------------------------===//
00194 
00195 namespace {
00196 
00197 typedef StringMap<Timer> Name2TimerMap;
00198 
00199 class Name2PairMap {
00200   StringMap<std::pair<TimerGroup*, Name2TimerMap> > Map;
00201 public:
00202   ~Name2PairMap() {
00203     for (StringMap<std::pair<TimerGroup*, Name2TimerMap> >::iterator
00204          I = Map.begin(), E = Map.end(); I != E; ++I)
00205       delete I->second.first;
00206   }
00207   
00208   Timer &get(StringRef Name, StringRef GroupName) {
00209     sys::SmartScopedLock<true> L(*TimerLock);
00210     
00211     std::pair<TimerGroup*, Name2TimerMap> &GroupEntry = Map[GroupName];
00212     
00213     if (!GroupEntry.first)
00214       GroupEntry.first = new TimerGroup(GroupName);
00215     
00216     Timer &T = GroupEntry.second[Name];
00217     if (!T.isInitialized())
00218       T.init(Name, *GroupEntry.first);
00219     return T;
00220   }
00221 };
00222 
00223 }
00224 
00225 static ManagedStatic<Name2TimerMap> NamedTimers;
00226 static ManagedStatic<Name2PairMap> NamedGroupedTimers;
00227 
00228 static Timer &getNamedRegionTimer(StringRef Name) {
00229   sys::SmartScopedLock<true> L(*TimerLock);
00230   
00231   Timer &T = (*NamedTimers)[Name];
00232   if (!T.isInitialized())
00233     T.init(Name);
00234   return T;
00235 }
00236 
00237 NamedRegionTimer::NamedRegionTimer(StringRef Name,
00238                                    bool Enabled)
00239   : TimeRegion(!Enabled ? nullptr : &getNamedRegionTimer(Name)) {}
00240 
00241 NamedRegionTimer::NamedRegionTimer(StringRef Name, StringRef GroupName,
00242                                    bool Enabled)
00243   : TimeRegion(!Enabled ? nullptr : &NamedGroupedTimers->get(Name, GroupName)){}
00244 
00245 //===----------------------------------------------------------------------===//
00246 //   TimerGroup Implementation
00247 //===----------------------------------------------------------------------===//
00248 
00249 /// TimerGroupList - This is the global list of TimerGroups, maintained by the
00250 /// TimerGroup ctor/dtor and is protected by the TimerLock lock.
00251 static TimerGroup *TimerGroupList = nullptr;
00252 
00253 TimerGroup::TimerGroup(StringRef name)
00254   : Name(name.begin(), name.end()), FirstTimer(nullptr) {
00255     
00256   // Add the group to TimerGroupList.
00257   sys::SmartScopedLock<true> L(*TimerLock);
00258   if (TimerGroupList)
00259     TimerGroupList->Prev = &Next;
00260   Next = TimerGroupList;
00261   Prev = &TimerGroupList;
00262   TimerGroupList = this;
00263 }
00264 
00265 TimerGroup::~TimerGroup() {
00266   // If the timer group is destroyed before the timers it owns, accumulate and
00267   // print the timing data.
00268   while (FirstTimer)
00269     removeTimer(*FirstTimer);
00270   
00271   // Remove the group from the TimerGroupList.
00272   sys::SmartScopedLock<true> L(*TimerLock);
00273   *Prev = Next;
00274   if (Next)
00275     Next->Prev = Prev;
00276 }
00277 
00278 
00279 void TimerGroup::removeTimer(Timer &T) {
00280   sys::SmartScopedLock<true> L(*TimerLock);
00281   
00282   // If the timer was started, move its data to TimersToPrint.
00283   if (T.Started)
00284     TimersToPrint.push_back(std::make_pair(T.Time, T.Name));
00285 
00286   T.TG = nullptr;
00287   
00288   // Unlink the timer from our list.
00289   *T.Prev = T.Next;
00290   if (T.Next)
00291     T.Next->Prev = T.Prev;
00292   
00293   // Print the report when all timers in this group are destroyed if some of
00294   // them were started.
00295   if (FirstTimer || TimersToPrint.empty())
00296     return;
00297   
00298   raw_ostream *OutStream = CreateInfoOutputFile();
00299   PrintQueuedTimers(*OutStream);
00300   delete OutStream;   // Close the file.
00301 }
00302 
00303 void TimerGroup::addTimer(Timer &T) {
00304   sys::SmartScopedLock<true> L(*TimerLock);
00305   
00306   // Add the timer to our list.
00307   if (FirstTimer)
00308     FirstTimer->Prev = &T.Next;
00309   T.Next = FirstTimer;
00310   T.Prev = &FirstTimer;
00311   FirstTimer = &T;
00312 }
00313 
00314 void TimerGroup::PrintQueuedTimers(raw_ostream &OS) {
00315   // Sort the timers in descending order by amount of time taken.
00316   std::sort(TimersToPrint.begin(), TimersToPrint.end());
00317   
00318   TimeRecord Total;
00319   for (unsigned i = 0, e = TimersToPrint.size(); i != e; ++i)
00320     Total += TimersToPrint[i].first;
00321   
00322   // Print out timing header.
00323   OS << "===" << std::string(73, '-') << "===\n";
00324   // Figure out how many spaces to indent TimerGroup name.
00325   unsigned Padding = (80-Name.length())/2;
00326   if (Padding > 80) Padding = 0;         // Don't allow "negative" numbers
00327   OS.indent(Padding) << Name << '\n';
00328   OS << "===" << std::string(73, '-') << "===\n";
00329   
00330   // If this is not an collection of ungrouped times, print the total time.
00331   // Ungrouped timers don't really make sense to add up.  We still print the
00332   // TOTAL line to make the percentages make sense.
00333   if (this != DefaultTimerGroup)
00334     OS << format("  Total Execution Time: %5.4f seconds (%5.4f wall clock)\n",
00335                  Total.getProcessTime(), Total.getWallTime());
00336   OS << '\n';
00337   
00338   if (Total.getUserTime())
00339     OS << "   ---User Time---";
00340   if (Total.getSystemTime())
00341     OS << "   --System Time--";
00342   if (Total.getProcessTime())
00343     OS << "   --User+System--";
00344   OS << "   ---Wall Time---";
00345   if (Total.getMemUsed())
00346     OS << "  ---Mem---";
00347   OS << "  --- Name ---\n";
00348   
00349   // Loop through all of the timing data, printing it out.
00350   for (unsigned i = 0, e = TimersToPrint.size(); i != e; ++i) {
00351     const std::pair<TimeRecord, std::string> &Entry = TimersToPrint[e-i-1];
00352     Entry.first.print(Total, OS);
00353     OS << Entry.second << '\n';
00354   }
00355   
00356   Total.print(Total, OS);
00357   OS << "Total\n\n";
00358   OS.flush();
00359   
00360   TimersToPrint.clear();
00361 }
00362 
00363 /// print - Print any started timers in this group and zero them.
00364 void TimerGroup::print(raw_ostream &OS) {
00365   sys::SmartScopedLock<true> L(*TimerLock);
00366 
00367   // See if any of our timers were started, if so add them to TimersToPrint and
00368   // reset them.
00369   for (Timer *T = FirstTimer; T; T = T->Next) {
00370     if (!T->Started) continue;
00371     TimersToPrint.push_back(std::make_pair(T->Time, T->Name));
00372     
00373     // Clear out the time.
00374     T->Started = 0;
00375     T->Time = TimeRecord();
00376   }
00377 
00378   // If any timers were started, print the group.
00379   if (!TimersToPrint.empty())
00380     PrintQueuedTimers(OS);
00381 }
00382 
00383 /// printAll - This static method prints all timers and clears them all out.
00384 void TimerGroup::printAll(raw_ostream &OS) {
00385   sys::SmartScopedLock<true> L(*TimerLock);
00386 
00387   for (TimerGroup *TG = TimerGroupList; TG; TG = TG->Next)
00388     TG->print(OS);
00389 }