CSE2410 Fall 2014 Bounce

// Copyright 2013 the V8 project authors. All rights reserved.

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// modification, are permitted provided that the following conditions are

// met:

//

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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#ifndef V8_PLATFORM_TIME_H_

#define V8_PLATFORM_TIME_H_

#include <ctime>

#include <limits>

#include "../allocation.h"

// Forward declarations.

extern "C" {

struct _FILETIME;

struct mach_timespec;

struct timespec;

struct timeval;

}

namespace v8 {

namespace internal {

class Time;

class TimeTicks;

// -----------------------------------------------------------------------------

// TimeDelta

//

// This class represents a duration of time, internally represented in

// microseonds.

class TimeDelta V8_FINAL BASE_EMBEDDED {

 public:

  TimeDelta() : delta_(0) {}

  // Converts units of time to TimeDeltas.

  static TimeDelta FromDays(int days);

  static TimeDelta FromHours(int hours);

  static TimeDelta FromMinutes(int minutes);

  static TimeDelta FromSeconds(int64_t seconds);

  static TimeDelta FromMilliseconds(int64_t milliseconds);

  static TimeDelta FromMicroseconds(int64_t microseconds) {

    return TimeDelta(microseconds);

  }

  static TimeDelta FromNanoseconds(int64_t nanoseconds);

  // Returns the time delta in some unit. The F versions return a floating

  // point value, the "regular" versions return a rounded-down value.

  //

  // InMillisecondsRoundedUp() instead returns an integer that is rounded up

  // to the next full millisecond.

  int InDays() const;

  int InHours() const;

  int InMinutes() const;

  double InSecondsF() const;

  int64_t InSeconds() const;

  double InMillisecondsF() const;

  int64_t InMilliseconds() const;

  int64_t InMillisecondsRoundedUp() const;

  int64_t InMicroseconds() const { return delta_; }

  int64_t InNanoseconds() const;

  // Converts to/from Mach time specs.

  static TimeDelta FromMachTimespec(struct mach_timespec ts);

  struct mach_timespec ToMachTimespec() const;

  // Converts to/from POSIX time specs.

  static TimeDelta FromTimespec(struct timespec ts);

  struct timespec ToTimespec() const;

  TimeDelta& operator=(const TimeDelta& other) {

    delta_ = other.delta_;

    return *this;

  }

  // Computations with other deltas.

  TimeDelta operator+(const TimeDelta& other) const {

    return TimeDelta(delta_ + other.delta_);

  }

  TimeDelta operator-(const TimeDelta& other) const {

    return TimeDelta(delta_ - other.delta_);

  }

  TimeDelta& operator+=(const TimeDelta& other) {

    delta_ += other.delta_;

    return *this;

  }

  TimeDelta& operator-=(const TimeDelta& other) {

    delta_ -= other.delta_;

    return *this;

  }

  TimeDelta operator-() const {

    return TimeDelta(-delta_);

  }

  double TimesOf(const TimeDelta& other) const {

    return static_cast<double>(delta_) / static_cast<double>(other.delta_);

  }

  double PercentOf(const TimeDelta& other) const {

    return TimesOf(other) * 100.0;

  }

  // Computations with ints, note that we only allow multiplicative operations

  // with ints, and additive operations with other deltas.

  TimeDelta operator*(int64_t a) const {

    return TimeDelta(delta_ * a);

  }

  TimeDelta operator/(int64_t a) const {

    return TimeDelta(delta_ / a);

  }

  TimeDelta& operator*=(int64_t a) {

    delta_ *= a;

    return *this;

  }

  TimeDelta& operator/=(int64_t a) {

    delta_ /= a;

    return *this;

  }

  int64_t operator/(const TimeDelta& other) const {

    return delta_ / other.delta_;

  }

  // Comparison operators.

  bool operator==(const TimeDelta& other) const {

    return delta_ == other.delta_;

  }

  bool operator!=(const TimeDelta& other) const {

    return delta_ != other.delta_;

  }

  bool operator<(const TimeDelta& other) const {

    return delta_ < other.delta_;

  }

  bool operator<=(const TimeDelta& other) const {

    return delta_ <= other.delta_;

  }

  bool operator>(const TimeDelta& other) const {

    return delta_ > other.delta_;

  }

  bool operator>=(const TimeDelta& other) const {

    return delta_ >= other.delta_;

  }

 private:

  // Constructs a delta given the duration in microseconds. This is private

  // to avoid confusion by callers with an integer constructor. Use

  // FromSeconds, FromMilliseconds, etc. instead.

  explicit TimeDelta(int64_t delta) : delta_(delta) {}

  // Delta in microseconds.

  int64_t delta_;

};

// -----------------------------------------------------------------------------

// Time

//

// This class represents an absolute point in time, internally represented as

// microseconds (s/1,000,000) since 00:00:00 UTC, January 1, 1970.

class Time V8_FINAL BASE_EMBEDDED {

 public:

  static const int64_t kMillisecondsPerSecond = 1000;

  static const int64_t kMicrosecondsPerMillisecond = 1000;

  static const int64_t kMicrosecondsPerSecond = kMicrosecondsPerMillisecond *

                                                kMillisecondsPerSecond;

  static const int64_t kMicrosecondsPerMinute = kMicrosecondsPerSecond * 60;

  static const int64_t kMicrosecondsPerHour = kMicrosecondsPerMinute * 60;

  static const int64_t kMicrosecondsPerDay = kMicrosecondsPerHour * 24;

  static const int64_t kMicrosecondsPerWeek = kMicrosecondsPerDay * 7;

  static const int64_t kNanosecondsPerMicrosecond = 1000;

  static const int64_t kNanosecondsPerSecond = kNanosecondsPerMicrosecond *

                                               kMicrosecondsPerSecond;

  // Contains the NULL time. Use Time::Now() to get the current time.

  Time() : us_(0) {}

  // Returns true if the time object has not been initialized.

  bool IsNull() const { return us_ == 0; }

  // Returns true if the time object is the maximum time.

  bool IsMax() const { return us_ == std::numeric_limits<int64_t>::max(); }

  // Returns the current time. Watch out, the system might adjust its clock

  // in which case time will actually go backwards. We don't guarantee that

  // times are increasing, or that two calls to Now() won't be the same.

  static Time Now();

  // Returns the current time. Same as Now() except that this function always

  // uses system time so that there are no discrepancies between the returned

  // time and system time even on virtual environments including our test bot.

  // For timing sensitive unittests, this function should be used.

  static Time NowFromSystemTime();

  // Returns the time for epoch in Unix-like system (Jan 1, 1970).

  static Time UnixEpoch() { return Time(0); }

  // Returns the maximum time, which should be greater than any reasonable time

  // with which we might compare it.

  static Time Max() { return Time(std::numeric_limits<int64_t>::max()); }

  // Converts to/from internal values. The meaning of the "internal value" is

  // completely up to the implementation, so it should be treated as opaque.

  static Time FromInternalValue(int64_t value) {

    return Time(value);

  }

  int64_t ToInternalValue() const {

    return us_;

  }

  // Converts to/from POSIX time specs.

  static Time FromTimespec(struct timespec ts);

  struct timespec ToTimespec() const;

  // Converts to/from POSIX time values.

  static Time FromTimeval(struct timeval tv);

  struct timeval ToTimeval() const;

  // Converts to/from Windows file times.

  static Time FromFiletime(struct _FILETIME ft);

  struct _FILETIME ToFiletime() const;

  // Converts to/from the Javascript convention for times, a number of

  // milliseconds since the epoch:

  static Time FromJsTime(double ms_since_epoch);

  double ToJsTime() const;

  Time& operator=(const Time& other) {

    us_ = other.us_;

    return *this;

  }

  // Compute the difference between two times.

  TimeDelta operator-(const Time& other) const {

    return TimeDelta::FromMicroseconds(us_ - other.us_);

  }

  // Modify by some time delta.

  Time& operator+=(const TimeDelta& delta) {

    us_ += delta.InMicroseconds();

    return *this;

  }

  Time& operator-=(const TimeDelta& delta) {

    us_ -= delta.InMicroseconds();

    return *this;

  }

  // Return a new time modified by some delta.

  Time operator+(const TimeDelta& delta) const {

    return Time(us_ + delta.InMicroseconds());

  }

  Time operator-(const TimeDelta& delta) const {

    return Time(us_ - delta.InMicroseconds());

  }

  // Comparison operators

  bool operator==(const Time& other) const {

    return us_ == other.us_;

  }

  bool operator!=(const Time& other) const {

    return us_ != other.us_;

  }

  bool operator<(const Time& other) const {

    return us_ < other.us_;

  }

  bool operator<=(const Time& other) const {

    return us_ <= other.us_;

  }

  bool operator>(const Time& other) const {

    return us_ > other.us_;

  }

  bool operator>=(const Time& other) const {

    return us_ >= other.us_;

  }

 private:

  explicit Time(int64_t us) : us_(us) {}

  // Time in microseconds in UTC.

  int64_t us_;

};

inline Time operator+(const TimeDelta& delta, const Time& time) {

  return time + delta;

}

// -----------------------------------------------------------------------------

// TimeTicks

//

// This class represents an abstract time that is most of the time incrementing

// for use in measuring time durations. It is internally represented in

// microseconds.  It can not be converted to a human-readable time, but is

// guaranteed not to decrease (if the user changes the computer clock,

// Time::Now() may actually decrease or jump).  But note that TimeTicks may

// "stand still", for example if the computer suspended.

class TimeTicks V8_FINAL BASE_EMBEDDED {

 public:

  TimeTicks() : ticks_(0) {}

  // Platform-dependent tick count representing "right now."

  // The resolution of this clock is ~1-15ms.  Resolution varies depending

  // on hardware/operating system configuration.

  // This method never returns a null TimeTicks.

  static TimeTicks Now();

  // Returns a platform-dependent high-resolution tick count. Implementation

  // is hardware dependent and may or may not return sub-millisecond

  // resolution.  THIS CALL IS GENERALLY MUCH MORE EXPENSIVE THAN Now() AND

  // SHOULD ONLY BE USED WHEN IT IS REALLY NEEDED.

  // This method never returns a null TimeTicks.

  static TimeTicks HighResolutionNow();

  // Returns true if the high-resolution clock is working on this system.

  static bool IsHighResolutionClockWorking();

  // Returns true if this object has not been initialized.

  bool IsNull() const { return ticks_ == 0; }

  // Converts to/from internal values. The meaning of the "internal value" is

  // completely up to the implementation, so it should be treated as opaque.

  static TimeTicks FromInternalValue(int64_t value) {

    return TimeTicks(value);

  }

  int64_t ToInternalValue() const {

    return ticks_;

  }

  TimeTicks& operator=(const TimeTicks other) {

    ticks_ = other.ticks_;

    return *this;

  }

  // Compute the difference between two times.

  TimeDelta operator-(const TimeTicks other) const {

    return TimeDelta::FromMicroseconds(ticks_ - other.ticks_);

  }

  // Modify by some time delta.

  TimeTicks& operator+=(const TimeDelta& delta) {

    ticks_ += delta.InMicroseconds();

    return *this;

  }

  TimeTicks& operator-=(const TimeDelta& delta) {

    ticks_ -= delta.InMicroseconds();

    return *this;

  }

  // Return a new TimeTicks modified by some delta.

  TimeTicks operator+(const TimeDelta& delta) const {

    return TimeTicks(ticks_ + delta.InMicroseconds());

  }

  TimeTicks operator-(const TimeDelta& delta) const {

    return TimeTicks(ticks_ - delta.InMicroseconds());

  }

  // Comparison operators

  bool operator==(const TimeTicks& other) const {

    return ticks_ == other.ticks_;

  }

  bool operator!=(const TimeTicks& other) const {

    return ticks_ != other.ticks_;

  }

  bool operator<(const TimeTicks& other) const {

    return ticks_ < other.ticks_;

  }

  bool operator<=(const TimeTicks& other) const {

    return ticks_ <= other.ticks_;

  }

  bool operator>(const TimeTicks& other) const {

    return ticks_ > other.ticks_;

  }

  bool operator>=(const TimeTicks& other) const {

    return ticks_ >= other.ticks_;

  }

 private:

  // Please use Now() to create a new object. This is for internal use

  // and testing. Ticks is in microseconds.

  explicit TimeTicks(int64_t ticks) : ticks_(ticks) {}

  // Tick count in microseconds.

  int64_t ticks_;

};

inline TimeTicks operator+(const TimeDelta& delta, const TimeTicks& ticks) {

  return ticks + delta;

}

} }  // namespace v8::internal

#endif  // V8_PLATFORM_TIME_H_