diff options
Diffstat (limited to 'deps/v8/src/base/platform/time.h')
-rw-r--r-- | deps/v8/src/base/platform/time.h | 400 |
1 files changed, 400 insertions, 0 deletions
diff --git a/deps/v8/src/base/platform/time.h b/deps/v8/src/base/platform/time.h new file mode 100644 index 000000000..b348236ff --- /dev/null +++ b/deps/v8/src/base/platform/time.h @@ -0,0 +1,400 @@ +// Copyright 2013 the V8 project authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#ifndef V8_BASE_PLATFORM_TIME_H_ +#define V8_BASE_PLATFORM_TIME_H_ + +#include <time.h> +#include <limits> + +#include "src/base/macros.h" + +// Forward declarations. +extern "C" { +struct _FILETIME; +struct mach_timespec; +struct timespec; +struct timeval; +} + +namespace v8 { +namespace base { + +class Time; +class TimeTicks; + +// ----------------------------------------------------------------------------- +// TimeDelta +// +// This class represents a duration of time, internally represented in +// microseonds. + +class TimeDelta V8_FINAL { + 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 { + 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 { + 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 Linux kernel timestamp for generating profiler events. This method + // returns null TimeTicks if the kernel cannot provide the timestamps (e.g., + // on non-Linux OS or if the kernel module for timestamps is not loaded). + + static TimeTicks KernelTimestampNow(); + static bool KernelTimestampAvailable(); + + // 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::base + +#endif // V8_BASE_PLATFORM_TIME_H_ |