/*

* Copyright (c) 2013, 2019, Oracle and/or its affiliates. All rights reserved.

* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

*

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* published by the Free Software Foundation.

*

* This code is distributed in the hope that it will be useful, but WITHOUT

* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

* FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

* version 2 for more details (a copy is included in the LICENSE file that

* accompanied this code).

*

* You should have received a copy of the GNU General Public License version

* 2 along with this work; if not, write to the Free Software Foundation,

* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

*

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#ifndef SHARE_UTILITIES_TICKS_HPP

#define SHARE_UTILITIES_TICKS_HPP

#include "jni.h"

#include "memory/allocation.hpp"

#include "utilities/macros.hpp"

// Time sources

class ElapsedCounterSource {

 public:

  typedef jlong Type;

  static uint64_t frequency();

  static Type now();

  static double seconds(Type value);

  static uint64_t milliseconds(Type value);

  static uint64_t microseconds(Type value);

  static uint64_t nanoseconds(Type value);

};

// Not guaranteed to be synchronized across hardware threads and

// therefore software threads, and can be updated asynchronously

// by software. now() can jump backwards as well as jump forward

// when threads query different cores/sockets.

// Very much not recommended for general use. Caveat emptor.

class FastUnorderedElapsedCounterSource {

 public:

  typedef jlong Type;

  static uint64_t frequency();

  static Type now();

  static double seconds(Type value);

  static uint64_t milliseconds(Type value);

  static uint64_t microseconds(Type value);

  static uint64_t nanoseconds(Type value);

};

template <typename T1, typename T2>

class PairRep {

 public:

  T1 val1;

  T2 val2;

  PairRep() : val1((T1)0), val2((T2)0) {}

  void operator+=(const PairRep& rhs) {

    val1 += rhs.val1;

    val2 += rhs.val2;

  }

  void operator-=(const PairRep& rhs) {

    val1 -= rhs.val1;

    val2 -= rhs.val2;

  }

  bool operator==(const PairRep& rhs) const {

    return val1 == rhs.val1;

  }

  bool operator!=(const PairRep& rhs) const {

    return !operator==(rhs);

  }

  bool operator<(const PairRep& rhs) const {

    return val1 < rhs.val1;

  }

  bool operator>(const PairRep& rhs) const {

    return val1 > rhs.val1;

  }

};

template <typename T1, typename T2>

PairRep<T1, T2> operator-(const PairRep<T1, T2>& lhs, const PairRep<T1, T2>& rhs) {

  PairRep<T1, T2> temp(lhs);

  temp -= rhs;

  return temp;

}

typedef PairRep<ElapsedCounterSource::Type, FastUnorderedElapsedCounterSource::Type> CompositeTime;

class CompositeElapsedCounterSource {

 public:

  typedef CompositeTime Type;

  static uint64_t frequency();

  static Type now();

  static double seconds(Type value);

  static uint64_t milliseconds(Type value);

  static uint64_t microseconds(Type value);

  static uint64_t nanoseconds(Type value);

};

template <typename TimeSource>

class Representation {

 public:

  typedef typename TimeSource::Type Type;

 protected:

  Type _rep;

  Representation(const Representation<TimeSource>& end, const Representation<TimeSource>& start) : _rep(end._rep - start._rep) {}

  Representation() : _rep() {}

 public:

  void operator+=(const Representation<TimeSource>& rhs) {

    _rep += rhs._rep;

  }

  void operator-=(const Representation<TimeSource>& rhs) {

    _rep -= rhs._rep;

  }

  bool operator==(const Representation<TimeSource>& rhs) const {

    return _rep == rhs._rep;

  }

  bool operator!=(const Representation<TimeSource>& rhs) const {

    return !operator==(rhs);

  }

  bool operator<(const Representation<TimeSource>& rhs) const {

    return _rep < rhs._rep;

  }

  bool operator>(const Representation<TimeSource>& rhs) const {

    return _rep > rhs._rep;

  }

  bool operator<=(const Representation<TimeSource>& rhs) const {

    return !operator>(rhs);

  }

  bool operator>=(const Representation<TimeSource>& rhs) const {

    return !operator<(rhs);

  }

  double seconds() const {

    return TimeSource::seconds(_rep);

  }

  uint64_t milliseconds() const {

    return TimeSource::milliseconds(_rep);

  }

  uint64_t microseconds() const {

    return TimeSource::microseconds(_rep);

  }

  uint64_t nanoseconds() const {

    return TimeSource::nanoseconds(_rep);

  }

};

template <typename TimeSource>

class CounterRepresentation : public Representation<TimeSource> {

 protected:

  CounterRepresentation(const CounterRepresentation& end, const CounterRepresentation& start) : Representation<TimeSource>(end, start) {}

  explicit CounterRepresentation(jlong value) : Representation<TimeSource>() {

    this->_rep = value;

  }

 public:

  CounterRepresentation() : Representation<TimeSource>() {}

  typename TimeSource::Type value() const { return this->_rep; }

  operator typename TimeSource::Type() { return value(); }

};

template <typename TimeSource>

class CompositeCounterRepresentation : public Representation<TimeSource> {

 protected:

  CompositeCounterRepresentation(const CompositeCounterRepresentation& end, const CompositeCounterRepresentation& start) :

    Representation<TimeSource>(end, start) {}

  explicit CompositeCounterRepresentation(jlong value) : Representation<TimeSource>() {

    this->_rep.val1 = value;

    this->_rep.val2 = value;

  }

 public:

  CompositeCounterRepresentation() : Representation<TimeSource>() {}

  ElapsedCounterSource::Type value() const { return this->_rep.val1; }

  FastUnorderedElapsedCounterSource::Type ft_value() const { return this->_rep.val2; }

};

template <template <typename> class, typename>

class TimeInstant;

template <template <typename> class Rep, typename TimeSource>

class TimeInterval : public Rep<TimeSource> {

  template <template <typename> class, typename>

  friend class TimeInstant;

  TimeInterval(const TimeInstant<Rep, TimeSource>& end, const TimeInstant<Rep, TimeSource>& start) : Rep<TimeSource>(end, start) {}

 public:

  TimeInterval() : Rep<TimeSource>() {}

  TimeInterval<Rep, TimeSource> operator+(const TimeInterval<Rep, TimeSource>& rhs) const {

    TimeInterval<Rep, TimeSource> temp(*this);

    temp += rhs;

    return temp;

  }

  TimeInterval<Rep, TimeSource> operator-(const TimeInterval<Rep, TimeSource>& rhs) const {

    TimeInterval<Rep, TimeSource> temp(*this);

    temp -= rhs;

    return temp;

  }

};

template <template <typename> class Rep, typename TimeSource>

class TimeInstant : public Rep<TimeSource> {

 public:

  TimeInstant() : Rep<TimeSource>() {}

  TimeInstant<Rep, TimeSource>& operator+=(const TimeInterval<Rep, TimeSource>& rhs) {

    Rep<TimeSource>::operator+=(rhs);

    return *this;

  }

  TimeInstant<Rep, TimeSource>& operator-=(const TimeInterval<Rep, TimeSource>& rhs) {

    Rep<TimeSource>::operator-=(rhs);

    return *this;

  }

  TimeInterval<Rep, TimeSource> operator+(const TimeInstant<Rep, TimeSource>& end) const {

    return TimeInterval<Rep, TimeSource>(end, *this);

  }

  TimeInterval<Rep, TimeSource> operator-(const TimeInstant<Rep, TimeSource>& start) const {

    return TimeInterval<Rep, TimeSource>(*this, start);

  }

  void stamp() {

    this->_rep = TimeSource::now();

  }

  static TimeInstant<Rep, TimeSource> now() {

    TimeInstant<Rep, TimeSource> temp;

    temp.stamp();

    return temp;

  }

 private:

  TimeInstant(jlong ticks) : Rep<TimeSource>(ticks) {}

  friend class GranularTimer;

  friend class ObjectSample;

  friend class EventEmitter;

  // GC unit tests

  friend class TimePartitionPhasesIteratorTest;

  friend class GCTimerTest;

};

#if INCLUDE_JFR

typedef TimeInstant<CompositeCounterRepresentation, CompositeElapsedCounterSource> Ticks;

typedef TimeInterval<CompositeCounterRepresentation, CompositeElapsedCounterSource> Tickspan;

#else

typedef TimeInstant<CounterRepresentation, ElapsedCounterSource> Ticks;

typedef TimeInterval<CounterRepresentation, ElapsedCounterSource> Tickspan;

#endif

#endif // SHARE_UTILITIES_TICKS_HPP