/* * Copyright (C) 2016 Apple Inc. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #ifndef WTF_WallTime_h #define WTF_WallTime_h #include <wtf/ClockType.h> #include <wtf/Seconds.h> namespace WTF { class MonotonicTime; class PrintStream; // The current time according to a wall clock (aka real time clock). This uses floating point // internally so that you can reason about infinity and other things that arise in math. It's // acceptable to use this to wrap NaN times, negative times, and infinite times, so long as they // are relative to the same clock. Specifically, WallTime should be used in agreement with the // principle that WallTime::now().secondsSinceEpoch().value() is the same as WTF::currentTime(). class WallTime { public: static const ClockType clockType = ClockType::Wall; // This is the epoch. So, x.secondsSinceEpoch() should be the same as x - WallTime(). WallTime() { } // Call this if you know for sure that the double represents time according to // WTF::currentTime(). It must be in seconds and it must be from the same time source. static WallTime fromRawSeconds(double value) { WallTime result; result.m_value = value; return result; } WTF_EXPORT_PRIVATE static WallTime now(); static WallTime infinity() { return fromRawSeconds(std::numeric_limits<double>::infinity()); } Seconds secondsSinceEpoch() const { return Seconds(m_value); } WallTime approximateWallTime() const { return *this; } WTF_EXPORT_PRIVATE MonotonicTime approximateMonotonicTime() const; explicit operator bool() const { return !!m_value; } WallTime operator+(Seconds other) const { return fromRawSeconds(m_value + other.value()); } WallTime operator-(Seconds other) const { return fromRawSeconds(m_value - other.value()); } // Time is a scalar and scalars can be negated as this could arise from algebraic // transformations. So, we allow it. WallTime operator-() const { return fromRawSeconds(-m_value); } WallTime& operator+=(Seconds other) { return *this = *this + other; } WallTime& operator-=(Seconds other) { return *this = *this - other; } Seconds operator-(WallTime other) const { return Seconds(m_value - other.m_value); } bool operator==(WallTime other) const { return m_value == other.m_value; } bool operator!=(WallTime other) const { return m_value != other.m_value; } bool operator<(WallTime other) const { return m_value < other.m_value; } bool operator>(WallTime other) const { return m_value > other.m_value; } bool operator<=(WallTime other) const { return m_value <= other.m_value; } bool operator>=(WallTime other) const { return m_value >= other.m_value; } WTF_EXPORT_PRIVATE void dump(PrintStream&) const; private: double m_value { 0 }; }; WTF_EXPORT_PRIVATE void sleep(WallTime); } // namespace WTF namespace std { inline bool isnan(WTF::WallTime time) { return std::isnan(time.secondsSinceEpoch().value()); } inline bool isinf(WTF::WallTime time) { return std::isinf(time.secondsSinceEpoch().value()); } inline bool isfinite(WTF::WallTime time) { return std::isfinite(time.secondsSinceEpoch().value()); } } // namespace std using WTF::WallTime; #endif // WTF_WallTime_h