Subversion Repositories QNX 8.QNX8 LLVM/Clang compiler suite

//===-- llvm/Support/Timer.h - Interval Timing Support ----------*- C++ -*-===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_SUPPORT_TIMER_H

#define LLVM_SUPPORT_TIMER_H

#include "llvm/ADT/StringMap.h"

#include "llvm/ADT/StringRef.h"

#include "llvm/Support/DataTypes.h"

#include <cassert>

#include <memory>

#include <string>

#include <vector>

namespace llvm {

class TimerGroup;

class raw_ostream;

class TimeRecord {

  double WallTime;               ///< Wall clock time elapsed in seconds.

  double UserTime;               ///< User time elapsed.

  double SystemTime;             ///< System time elapsed.

  ssize_t MemUsed;               ///< Memory allocated (in bytes).

  uint64_t InstructionsExecuted; ///< Number of instructions executed

public:

  TimeRecord()

      : WallTime(0), UserTime(0), SystemTime(0), MemUsed(0),

        InstructionsExecuted(0) {}

  /// Get the current time and memory usage.  If Start is true we get the memory

  /// usage before the time, otherwise we get time before memory usage.  This

  /// matters if the time to get the memory usage is significant and shouldn't

  /// be counted as part of a duration.

  static TimeRecord getCurrentTime(bool Start = true);

  double getProcessTime() const { return UserTime + SystemTime; }

  double getUserTime() const { return UserTime; }

  double getSystemTime() const { return SystemTime; }

  double getWallTime() const { return WallTime; }

  ssize_t getMemUsed() const { return MemUsed; }

  uint64_t getInstructionsExecuted() const { return InstructionsExecuted; }

  bool operator<(const TimeRecord &T) const {

    // Sort by Wall Time elapsed, as it is the only thing really accurate

    return WallTime < T.WallTime;

  }

  void operator+=(const TimeRecord &RHS) {

    WallTime += RHS.WallTime;

    UserTime += RHS.UserTime;

    SystemTime += RHS.SystemTime;

    MemUsed += RHS.MemUsed;

    InstructionsExecuted += RHS.InstructionsExecuted;

  }

  void operator-=(const TimeRecord &RHS) {

    WallTime -= RHS.WallTime;

    UserTime -= RHS.UserTime;

    SystemTime -= RHS.SystemTime;

    MemUsed -= RHS.MemUsed;

    InstructionsExecuted -= RHS.InstructionsExecuted;

  }

  /// Print the current time record to \p OS, with a breakdown showing

  /// contributions to the \p Total time record.

  void print(const TimeRecord &Total, raw_ostream &OS) const;

};

/// This class is used to track the amount of time spent between invocations of

/// its startTimer()/stopTimer() methods.  Given appropriate OS support it can

/// also keep track of the RSS of the program at various points.  By default,

/// the Timer will print the amount of time it has captured to standard error

/// when the last timer is destroyed, otherwise it is printed when its

/// TimerGroup is destroyed.  Timers do not print their information if they are

/// never started.

class Timer {

  TimeRecord Time;          ///< The total time captured.

  TimeRecord StartTime;     ///< The time startTimer() was last called.

  std::string Name;         ///< The name of this time variable.

  std::string Description;  ///< Description of this time variable.

  bool Running = false;     ///< Is the timer currently running?

  bool Triggered = false;   ///< Has the timer ever been triggered?

  TimerGroup *TG = nullptr; ///< The TimerGroup this Timer is in.

  Timer **Prev = nullptr;   ///< Pointer to \p Next of previous timer in group.

  Timer *Next = nullptr;    ///< Next timer in the group.

public:

  explicit Timer(StringRef TimerName, StringRef TimerDescription) {

    init(TimerName, TimerDescription);

  }

  Timer(StringRef TimerName, StringRef TimerDescription, TimerGroup &tg) {

    init(TimerName, TimerDescription, tg);

  }

  Timer(const Timer &RHS) {

    assert(!RHS.TG && "Can only copy uninitialized timers");

  }

  const Timer &operator=(const Timer &T) {

    assert(!TG && !T.TG && "Can only assign uninit timers");

    return *this;

  }

  ~Timer();

  /// Create an uninitialized timer, client must use 'init'.

  explicit Timer() = default;

  void init(StringRef TimerName, StringRef TimerDescription);

  void init(StringRef TimerName, StringRef TimerDescription, TimerGroup &tg);

  const std::string &getName() const { return Name; }

  const std::string &getDescription() const { return Description; }

  bool isInitialized() const { return TG != nullptr; }

  /// Check if the timer is currently running.

  bool isRunning() const { return Running; }

  /// Check if startTimer() has ever been called on this timer.

  bool hasTriggered() const { return Triggered; }

  /// Start the timer running.  Time between calls to startTimer/stopTimer is

  /// counted by the Timer class.  Note that these calls must be correctly

  /// paired.

  void startTimer();

  /// Stop the timer.

  void stopTimer();

  /// Clear the timer state.

  void clear();

  /// Return the duration for which this timer has been running.

  TimeRecord getTotalTime() const { return Time; }

private:

  friend class TimerGroup;

};

/// The TimeRegion class is used as a helper class to call the startTimer() and

/// stopTimer() methods of the Timer class.  When the object is constructed, it

/// starts the timer specified as its argument.  When it is destroyed, it stops

/// the relevant timer.  This makes it easy to time a region of code.

class TimeRegion {

  Timer *T;

  TimeRegion(const TimeRegion &) = delete;

public:

  explicit TimeRegion(Timer &t) : T(&t) {

    T->startTimer();

  }

  explicit TimeRegion(Timer *t) : T(t) {

    if (T) T->startTimer();

  }

  ~TimeRegion() {

    if (T) T->stopTimer();

  }

};

/// This class is basically a combination of TimeRegion and Timer.  It allows

/// you to declare a new timer, AND specify the region to time, all in one

/// statement.  All timers with the same name are merged.  This is primarily

/// used for debugging and for hunting performance problems.

struct NamedRegionTimer : public TimeRegion {

  explicit NamedRegionTimer(StringRef Name, StringRef Description,

                            StringRef GroupName,

                            StringRef GroupDescription, bool Enabled = true);

};

/// The TimerGroup class is used to group together related timers into a single

/// report that is printed when the TimerGroup is destroyed.  It is illegal to

/// destroy a TimerGroup object before all of the Timers in it are gone.  A

/// TimerGroup can be specified for a newly created timer in its constructor.

class TimerGroup {

  struct PrintRecord {

    TimeRecord Time;

    std::string Name;

    std::string Description;

    PrintRecord(const PrintRecord &Other) = default;

    PrintRecord &operator=(const PrintRecord &Other) = default;

    PrintRecord(const TimeRecord &Time, const std::string &Name,

                const std::string &Description)

      : Time(Time), Name(Name), Description(Description) {}

    bool operator <(const PrintRecord &Other) const {

      return Time < Other.Time;

    }

  };

  std::string Name;

  std::string Description;

  Timer *FirstTimer = nullptr; ///< First timer in the group.

  std::vector<PrintRecord> TimersToPrint;

  TimerGroup **Prev; ///< Pointer to Next field of previous timergroup in list.

  TimerGroup *Next;  ///< Pointer to next timergroup in list.

  TimerGroup(const TimerGroup &TG) = delete;

  void operator=(const TimerGroup &TG) = delete;

public:

  explicit TimerGroup(StringRef Name, StringRef Description);

  explicit TimerGroup(StringRef Name, StringRef Description,

                      const StringMap<TimeRecord> &Records);

  ~TimerGroup();

  void setName(StringRef NewName, StringRef NewDescription) {

    Name.assign(NewName.begin(), NewName.end());

    Description.assign(NewDescription.begin(), NewDescription.end());

  }

  /// Print any started timers in this group, optionally resetting timers after

  /// printing them.

  void print(raw_ostream &OS, bool ResetAfterPrint = false);

  /// Clear all timers in this group.

  void clear();

  /// This static method prints all timers.

  static void printAll(raw_ostream &OS);

  /// Clear out all timers. This is mostly used to disable automatic

  /// printing on shutdown, when timers have already been printed explicitly

  /// using \c printAll or \c printJSONValues.

  static void clearAll();

  const char *printJSONValues(raw_ostream &OS, const char *delim);

  /// Prints all timers as JSON key/value pairs.

  static const char *printAllJSONValues(raw_ostream &OS, const char *delim);

  /// Ensure global objects required for statistics printing are initialized.

  /// This function is used by the Statistic code to ensure correct order of

  /// global constructors and destructors.

  static void constructForStatistics();

  /// This makes the default group unmanaged, and lets the user manage the

  /// group's lifetime.

  static std::unique_ptr<TimerGroup> aquireDefaultGroup();

private:

  friend class Timer;

  friend void PrintStatisticsJSON(raw_ostream &OS);

  void addTimer(Timer &T);

  void removeTimer(Timer &T);

  void prepareToPrintList(bool reset_time = false);

  void PrintQueuedTimers(raw_ostream &OS);

  void printJSONValue(raw_ostream &OS, const PrintRecord &R,

                      const char *suffix, double Value);

};

} // end namespace llvm

#endif