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Diffstat (limited to 'security/sandbox/chromium/base/time/time.h')
| -rw-r--r-- | security/sandbox/chromium/base/time/time.h | 764 |
1 files changed, 0 insertions, 764 deletions
diff --git a/security/sandbox/chromium/base/time/time.h b/security/sandbox/chromium/base/time/time.h deleted file mode 100644 index 066d91083..000000000 --- a/security/sandbox/chromium/base/time/time.h +++ /dev/null @@ -1,764 +0,0 @@ -// Copyright (c) 2012 The Chromium Authors. All rights reserved. -// Use of this source code is governed by a BSD-style license that can be -// found in the LICENSE file. - -// Time represents an absolute point in coordinated universal time (UTC), -// internally represented as microseconds (s/1,000,000) since the Windows epoch -// (1601-01-01 00:00:00 UTC). System-dependent clock interface routines are -// defined in time_PLATFORM.cc. Note that values for Time may skew and jump -// around as the operating system makes adjustments to synchronize (e.g., with -// NTP servers). Thus, client code that uses the Time class must account for -// this. -// -// TimeDelta represents a duration of time, internally represented in -// microseconds. -// -// TimeTicks and ThreadTicks represent an abstract time that is most of the time -// incrementing, for use in measuring time durations. Internally, they are -// represented in microseconds. They can not be converted to a human-readable -// time, but are guaranteed not to decrease (unlike the Time class). Note that -// TimeTicks may "stand still" (e.g., if the computer is suspended), and -// ThreadTicks will "stand still" whenever the thread has been de-scheduled by -// the operating system. -// -// All time classes are copyable, assignable, and occupy 64-bits per -// instance. Thus, they can be efficiently passed by-value (as opposed to -// by-reference). -// -// Definitions of operator<< are provided to make these types work with -// DCHECK_EQ() and other log macros. For human-readable formatting, see -// "base/i18n/time_formatting.h". -// -// So many choices! Which time class should you use? Examples: -// -// Time: Interpreting the wall-clock time provided by a remote -// system. Detecting whether cached resources have -// expired. Providing the user with a display of the current date -// and time. Determining the amount of time between events across -// re-boots of the machine. -// -// TimeTicks: Tracking the amount of time a task runs. Executing delayed -// tasks at the right time. Computing presentation timestamps. -// Synchronizing audio and video using TimeTicks as a common -// reference clock (lip-sync). Measuring network round-trip -// latency. -// -// ThreadTicks: Benchmarking how long the current thread has been doing actual -// work. - -#ifndef BASE_TIME_TIME_H_ -#define BASE_TIME_TIME_H_ - -#include <stdint.h> -#include <time.h> - -#include <iosfwd> -#include <limits> - -#include "base/base_export.h" -#include "base/numerics/safe_math.h" -#include "build/build_config.h" - -#if defined(OS_MACOSX) -#include <CoreFoundation/CoreFoundation.h> -// Avoid Mac system header macro leak. -#undef TYPE_BOOL -#endif - -#if defined(OS_POSIX) -#include <unistd.h> -#include <sys/time.h> -#endif - -#if defined(OS_WIN) -// For FILETIME in FromFileTime, until it moves to a new converter class. -// See TODO(iyengar) below. -#include <windows.h> - -#include "base/gtest_prod_util.h" -#endif - -namespace base { - -class TimeDelta; - -// The functions in the time_internal namespace are meant to be used only by the -// time classes and functions. Please use the math operators defined in the -// time classes instead. -namespace time_internal { - -// Add or subtract |value| from a TimeDelta. The int64_t argument and return -// value are in terms of a microsecond timebase. -BASE_EXPORT int64_t SaturatedAdd(TimeDelta delta, int64_t value); -BASE_EXPORT int64_t SaturatedSub(TimeDelta delta, int64_t value); - -// Clamp |value| on overflow and underflow conditions. The int64_t argument and -// return value are in terms of a microsecond timebase. -BASE_EXPORT int64_t FromCheckedNumeric(const CheckedNumeric<int64_t> value); - -} // namespace time_internal - -// TimeDelta ------------------------------------------------------------------ - -class BASE_EXPORT TimeDelta { - 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 secs); - static TimeDelta FromMilliseconds(int64_t ms); - static TimeDelta FromSecondsD(double secs); - static TimeDelta FromMillisecondsD(double ms); - static TimeDelta FromMicroseconds(int64_t us); -#if defined(OS_WIN) - static TimeDelta FromQPCValue(LONGLONG qpc_value); -#endif - - // Converts an integer value representing TimeDelta to a class. This is used - // when deserializing a |TimeDelta| structure, using a value known to be - // compatible. It is not provided as a constructor because the integer type - // may be unclear from the perspective of a caller. - static TimeDelta FromInternalValue(int64_t delta) { return TimeDelta(delta); } - - // Returns the maximum time delta, which should be greater than any reasonable - // time delta we might compare it to. Adding or subtracting the maximum time - // delta to a time or another time delta has an undefined result. - static TimeDelta Max(); - - // Returns the internal numeric value of the TimeDelta object. Please don't - // use this and do arithmetic on it, as it is more error prone than using the - // provided operators. - // For serializing, use FromInternalValue to reconstitute. - int64_t ToInternalValue() const { return delta_; } - - // Returns the magnitude (absolute value) of this TimeDelta. - TimeDelta magnitude() const { - // Some toolchains provide an incomplete C++11 implementation and lack an - // int64_t overload for std::abs(). The following is a simple branchless - // implementation: - const int64_t mask = delta_ >> (sizeof(delta_) * 8 - 1); - return TimeDelta((delta_ + mask) ^ mask); - } - - // Returns true if the time delta is zero. - bool is_zero() const { - return delta_ == 0; - } - - // Returns true if the time delta is the maximum time delta. - bool is_max() const { return delta_ == std::numeric_limits<int64_t>::max(); } - -#if defined(OS_POSIX) - struct timespec ToTimeSpec() const; -#endif - - // 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; - - TimeDelta& operator=(TimeDelta other) { - delta_ = other.delta_; - return *this; - } - - // Computations with other deltas. - TimeDelta operator+(TimeDelta other) const { - return TimeDelta(time_internal::SaturatedAdd(*this, other.delta_)); - } - TimeDelta operator-(TimeDelta other) const { - return TimeDelta(time_internal::SaturatedSub(*this, other.delta_)); - } - - TimeDelta& operator+=(TimeDelta other) { - return *this = (*this + other); - } - TimeDelta& operator-=(TimeDelta other) { - return *this = (*this - other); - } - TimeDelta operator-() const { - return TimeDelta(-delta_); - } - - // Computations with numeric types. - template<typename T> - TimeDelta operator*(T a) const { - CheckedNumeric<int64_t> rv(delta_); - rv *= a; - return TimeDelta(time_internal::FromCheckedNumeric(rv)); - } - template<typename T> - TimeDelta operator/(T a) const { - CheckedNumeric<int64_t> rv(delta_); - rv /= a; - return TimeDelta(time_internal::FromCheckedNumeric(rv)); - } - template<typename T> - TimeDelta& operator*=(T a) { - return *this = (*this * a); - } - template<typename T> - TimeDelta& operator/=(T a) { - return *this = (*this / a); - } - - int64_t operator/(TimeDelta a) const { return delta_ / a.delta_; } - TimeDelta operator%(TimeDelta a) const { - return TimeDelta(delta_ % a.delta_); - } - - // Comparison operators. - bool operator==(TimeDelta other) const { - return delta_ == other.delta_; - } - bool operator!=(TimeDelta other) const { - return delta_ != other.delta_; - } - bool operator<(TimeDelta other) const { - return delta_ < other.delta_; - } - bool operator<=(TimeDelta other) const { - return delta_ <= other.delta_; - } - bool operator>(TimeDelta other) const { - return delta_ > other.delta_; - } - bool operator>=(TimeDelta other) const { - return delta_ >= other.delta_; - } - - private: - friend int64_t time_internal::SaturatedAdd(TimeDelta delta, int64_t value); - friend int64_t time_internal::SaturatedSub(TimeDelta delta, int64_t value); - - // 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_us) : delta_(delta_us) {} - - // Private method to build a delta from a double. - static TimeDelta FromDouble(double value); - - // Delta in microseconds. - int64_t delta_; -}; - -template<typename T> -inline TimeDelta operator*(T a, TimeDelta td) { - return td * a; -} - -// For logging use only. -BASE_EXPORT std::ostream& operator<<(std::ostream& os, TimeDelta time_delta); - -// Do not reference the time_internal::TimeBase template class directly. Please -// use one of the time subclasses instead, and only reference the public -// TimeBase members via those classes. -namespace time_internal { - -// TimeBase-------------------------------------------------------------------- - -// Provides value storage and comparison/math operations common to all time -// classes. Each subclass provides for strong type-checking to ensure -// semantically meaningful comparison/math of time values from the same clock -// source or timeline. -template<class TimeClass> -class TimeBase { - public: - static const int64_t kHoursPerDay = 24; - static const int64_t kMillisecondsPerSecond = 1000; - static const int64_t kMillisecondsPerDay = - kMillisecondsPerSecond * 60 * 60 * kHoursPerDay; - 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 * kHoursPerDay; - static const int64_t kMicrosecondsPerWeek = kMicrosecondsPerDay * 7; - static const int64_t kNanosecondsPerMicrosecond = 1000; - static const int64_t kNanosecondsPerSecond = - kNanosecondsPerMicrosecond * kMicrosecondsPerSecond; - - // Returns true if this object has not been initialized. - // - // Warning: Be careful when writing code that performs math on time values, - // since it's possible to produce a valid "zero" result that should not be - // interpreted as a "null" value. - bool is_null() const { - return us_ == 0; - } - - // Returns true if this object represents the maximum time. - bool is_max() const { return us_ == std::numeric_limits<int64_t>::max(); } - - // For serializing only. Use FromInternalValue() to reconstitute. Please don't - // use this and do arithmetic on it, as it is more error prone than using the - // provided operators. - int64_t ToInternalValue() const { return us_; } - - TimeClass& operator=(TimeClass other) { - us_ = other.us_; - return *(static_cast<TimeClass*>(this)); - } - - // Compute the difference between two times. - TimeDelta operator-(TimeClass other) const { - return TimeDelta::FromMicroseconds(us_ - other.us_); - } - - // Return a new time modified by some delta. - TimeClass operator+(TimeDelta delta) const { - return TimeClass(time_internal::SaturatedAdd(delta, us_)); - } - TimeClass operator-(TimeDelta delta) const { - return TimeClass(-time_internal::SaturatedSub(delta, us_)); - } - - // Modify by some time delta. - TimeClass& operator+=(TimeDelta delta) { - return static_cast<TimeClass&>(*this = (*this + delta)); - } - TimeClass& operator-=(TimeDelta delta) { - return static_cast<TimeClass&>(*this = (*this - delta)); - } - - // Comparison operators - bool operator==(TimeClass other) const { - return us_ == other.us_; - } - bool operator!=(TimeClass other) const { - return us_ != other.us_; - } - bool operator<(TimeClass other) const { - return us_ < other.us_; - } - bool operator<=(TimeClass other) const { - return us_ <= other.us_; - } - bool operator>(TimeClass other) const { - return us_ > other.us_; - } - bool operator>=(TimeClass other) const { - return us_ >= other.us_; - } - - // Converts an integer value representing TimeClass to a class. This is used - // when deserializing a |TimeClass| structure, using a value known to be - // compatible. It is not provided as a constructor because the integer type - // may be unclear from the perspective of a caller. - static TimeClass FromInternalValue(int64_t us) { return TimeClass(us); } - - protected: - explicit TimeBase(int64_t us) : us_(us) {} - - // Time value in a microsecond timebase. - int64_t us_; -}; - -} // namespace time_internal - -template<class TimeClass> -inline TimeClass operator+(TimeDelta delta, TimeClass t) { - return t + delta; -} - -// Time ----------------------------------------------------------------------- - -// Represents a wall clock time in UTC. Values are not guaranteed to be -// monotonically non-decreasing and are subject to large amounts of skew. -class BASE_EXPORT Time : public time_internal::TimeBase<Time> { - public: - // The representation of Jan 1, 1970 UTC in microseconds since the - // platform-dependent epoch. - static const int64_t kTimeTToMicrosecondsOffset; - -#if !defined(OS_WIN) - // On Mac & Linux, this value is the delta from the Windows epoch of 1601 to - // the Posix delta of 1970. This is used for migrating between the old - // 1970-based epochs to the new 1601-based ones. It should be removed from - // this global header and put in the platform-specific ones when we remove the - // migration code. - static const int64_t kWindowsEpochDeltaMicroseconds; -#else - // To avoid overflow in QPC to Microseconds calculations, since we multiply - // by kMicrosecondsPerSecond, then the QPC value should not exceed - // (2^63 - 1) / 1E6. If it exceeds that threshold, we divide then multiply. - enum : int64_t{kQPCOverflowThreshold = 0x8637BD05AF7}; -#endif - - // Represents an exploded time that can be formatted nicely. This is kind of - // like the Win32 SYSTEMTIME structure or the Unix "struct tm" with a few - // additions and changes to prevent errors. - struct BASE_EXPORT Exploded { - int year; // Four digit year "2007" - int month; // 1-based month (values 1 = January, etc.) - int day_of_week; // 0-based day of week (0 = Sunday, etc.) - int day_of_month; // 1-based day of month (1-31) - int hour; // Hour within the current day (0-23) - int minute; // Minute within the current hour (0-59) - int second; // Second within the current minute (0-59 plus leap - // seconds which may take it up to 60). - int millisecond; // Milliseconds within the current second (0-999) - - // A cursory test for whether the data members are within their - // respective ranges. A 'true' return value does not guarantee the - // Exploded value can be successfully converted to a Time value. - bool HasValidValues() const; - }; - - // Contains the NULL time. Use Time::Now() to get the current time. - Time() : TimeBase(0) { - } - - // Returns the time for epoch in Unix-like system (Jan 1, 1970). - static Time UnixEpoch(); - - // 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 maximum time, which should be greater than any reasonable time - // with which we might compare it. - static Time Max(); - - // 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(); - - // Converts to/from time_t in UTC and a Time class. - // TODO(brettw) this should be removed once everybody starts using the |Time| - // class. - static Time FromTimeT(time_t tt); - time_t ToTimeT() const; - - // Converts time to/from a double which is the number of seconds since epoch - // (Jan 1, 1970). Webkit uses this format to represent time. - // Because WebKit initializes double time value to 0 to indicate "not - // initialized", we map it to empty Time object that also means "not - // initialized". - static Time FromDoubleT(double dt); - double ToDoubleT() const; - -#if defined(OS_POSIX) - // Converts the timespec structure to time. MacOS X 10.8.3 (and tentatively, - // earlier versions) will have the |ts|'s tv_nsec component zeroed out, - // having a 1 second resolution, which agrees with - // https://developer.apple.com/legacy/library/#technotes/tn/tn1150.html#HFSPlusDates. - static Time FromTimeSpec(const timespec& ts); -#endif - - // Converts to/from the Javascript convention for times, a number of - // milliseconds since the epoch: - // https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Date/getTime. - static Time FromJsTime(double ms_since_epoch); - double ToJsTime() const; - - // Converts to Java convention for times, a number of - // milliseconds since the epoch. - int64_t ToJavaTime() const; - -#if defined(OS_POSIX) - static Time FromTimeVal(struct timeval t); - struct timeval ToTimeVal() const; -#endif - -#if defined(OS_MACOSX) - static Time FromCFAbsoluteTime(CFAbsoluteTime t); - CFAbsoluteTime ToCFAbsoluteTime() const; -#endif - -#if defined(OS_WIN) - static Time FromFileTime(FILETIME ft); - FILETIME ToFileTime() const; - - // The minimum time of a low resolution timer. This is basically a windows - // constant of ~15.6ms. While it does vary on some older OS versions, we'll - // treat it as static across all windows versions. - static const int kMinLowResolutionThresholdMs = 16; - - // Enable or disable Windows high resolution timer. - static void EnableHighResolutionTimer(bool enable); - - // Activates or deactivates the high resolution timer based on the |activate| - // flag. If the HighResolutionTimer is not Enabled (see - // EnableHighResolutionTimer), this function will return false. Otherwise - // returns true. Each successful activate call must be paired with a - // subsequent deactivate call. - // All callers to activate the high resolution timer must eventually call - // this function to deactivate the high resolution timer. - static bool ActivateHighResolutionTimer(bool activate); - - // Returns true if the high resolution timer is both enabled and activated. - // This is provided for testing only, and is not tracked in a thread-safe - // way. - static bool IsHighResolutionTimerInUse(); -#endif - - // Converts an exploded structure representing either the local time or UTC - // into a Time class. - static Time FromUTCExploded(const Exploded& exploded) { - return FromExploded(false, exploded); - } - static Time FromLocalExploded(const Exploded& exploded) { - return FromExploded(true, exploded); - } - - // Converts a string representation of time to a Time object. - // An example of a time string which is converted is as below:- - // "Tue, 15 Nov 1994 12:45:26 GMT". If the timezone is not specified - // in the input string, FromString assumes local time and FromUTCString - // assumes UTC. A timezone that cannot be parsed (e.g. "UTC" which is not - // specified in RFC822) is treated as if the timezone is not specified. - // TODO(iyengar) Move the FromString/FromTimeT/ToTimeT/FromFileTime to - // a new time converter class. - static bool FromString(const char* time_string, Time* parsed_time) { - return FromStringInternal(time_string, true, parsed_time); - } - static bool FromUTCString(const char* time_string, Time* parsed_time) { - return FromStringInternal(time_string, false, parsed_time); - } - - // Fills the given exploded structure with either the local time or UTC from - // this time structure (containing UTC). - void UTCExplode(Exploded* exploded) const { - return Explode(false, exploded); - } - void LocalExplode(Exploded* exploded) const { - return Explode(true, exploded); - } - - // Rounds this time down to the nearest day in local time. It will represent - // midnight on that day. - Time LocalMidnight() const; - - private: - friend class time_internal::TimeBase<Time>; - - explicit Time(int64_t us) : TimeBase(us) {} - - // Explodes the given time to either local time |is_local = true| or UTC - // |is_local = false|. - void Explode(bool is_local, Exploded* exploded) const; - - // Unexplodes a given time assuming the source is either local time - // |is_local = true| or UTC |is_local = false|. - static Time FromExploded(bool is_local, const Exploded& exploded); - - // Converts a string representation of time to a Time object. - // An example of a time string which is converted is as below:- - // "Tue, 15 Nov 1994 12:45:26 GMT". If the timezone is not specified - // in the input string, local time |is_local = true| or - // UTC |is_local = false| is assumed. A timezone that cannot be parsed - // (e.g. "UTC" which is not specified in RFC822) is treated as if the - // timezone is not specified. - static bool FromStringInternal(const char* time_string, - bool is_local, - Time* parsed_time); -}; - -// Inline the TimeDelta factory methods, for fast TimeDelta construction. - -// static -inline TimeDelta TimeDelta::FromDays(int days) { - if (days == std::numeric_limits<int>::max()) - return Max(); - return TimeDelta(days * Time::kMicrosecondsPerDay); -} - -// static -inline TimeDelta TimeDelta::FromHours(int hours) { - if (hours == std::numeric_limits<int>::max()) - return Max(); - return TimeDelta(hours * Time::kMicrosecondsPerHour); -} - -// static -inline TimeDelta TimeDelta::FromMinutes(int minutes) { - if (minutes == std::numeric_limits<int>::max()) - return Max(); - return TimeDelta(minutes * Time::kMicrosecondsPerMinute); -} - -// static -inline TimeDelta TimeDelta::FromSeconds(int64_t secs) { - return TimeDelta(secs) * Time::kMicrosecondsPerSecond; -} - -// static -inline TimeDelta TimeDelta::FromMilliseconds(int64_t ms) { - return TimeDelta(ms) * Time::kMicrosecondsPerMillisecond; -} - -// static -inline TimeDelta TimeDelta::FromSecondsD(double secs) { - return FromDouble(secs * Time::kMicrosecondsPerSecond); -} - -// static -inline TimeDelta TimeDelta::FromMillisecondsD(double ms) { - return FromDouble(ms * Time::kMicrosecondsPerMillisecond); -} - -// static -inline TimeDelta TimeDelta::FromMicroseconds(int64_t us) { - return TimeDelta(us); -} - -// static -inline TimeDelta TimeDelta::FromDouble(double value) { - double max_magnitude = std::numeric_limits<int64_t>::max(); - TimeDelta delta = TimeDelta(static_cast<int64_t>(value)); - if (value > max_magnitude) - delta = Max(); - else if (value < -max_magnitude) - delta = -Max(); - return delta; -} - -// For logging use only. -BASE_EXPORT std::ostream& operator<<(std::ostream& os, Time time); - -// TimeTicks ------------------------------------------------------------------ - -// Represents monotonically non-decreasing clock time. -class BASE_EXPORT TimeTicks : public time_internal::TimeBase<TimeTicks> { - public: - TimeTicks() : TimeBase(0) { - } - - // Platform-dependent tick count representing "right now." When - // IsHighResolution() returns false, the resolution of the clock could be - // as coarse as ~15.6ms. Otherwise, the resolution should be no worse than one - // microsecond. - static TimeTicks Now(); - - // Returns true if the high resolution clock is working on this system and - // Now() will return high resolution values. Note that, on systems where the - // high resolution clock works but is deemed inefficient, the low resolution - // clock will be used instead. - static bool IsHighResolution(); - -#if defined(OS_WIN) - // Translates an absolute QPC timestamp into a TimeTicks value. The returned - // value has the same origin as Now(). Do NOT attempt to use this if - // IsHighResolution() returns false. - static TimeTicks FromQPCValue(LONGLONG qpc_value); -#endif - - // Get an estimate of the TimeTick value at the time of the UnixEpoch. Because - // Time and TimeTicks respond differently to user-set time and NTP - // adjustments, this number is only an estimate. Nevertheless, this can be - // useful when you need to relate the value of TimeTicks to a real time and - // date. Note: Upon first invocation, this function takes a snapshot of the - // realtime clock to establish a reference point. This function will return - // the same value for the duration of the application, but will be different - // in future application runs. - static TimeTicks UnixEpoch(); - - // Returns |this| snapped to the next tick, given a |tick_phase| and - // repeating |tick_interval| in both directions. |this| may be before, - // after, or equal to the |tick_phase|. - TimeTicks SnappedToNextTick(TimeTicks tick_phase, - TimeDelta tick_interval) const; - -#if defined(OS_WIN) - protected: - typedef DWORD (*TickFunctionType)(void); - static TickFunctionType SetMockTickFunction(TickFunctionType ticker); -#endif - - private: - friend class time_internal::TimeBase<TimeTicks>; - - // Please use Now() to create a new object. This is for internal use - // and testing. - explicit TimeTicks(int64_t us) : TimeBase(us) {} -}; - -// For logging use only. -BASE_EXPORT std::ostream& operator<<(std::ostream& os, TimeTicks time_ticks); - -// ThreadTicks ---------------------------------------------------------------- - -// Represents a clock, specific to a particular thread, than runs only while the -// thread is running. -class BASE_EXPORT ThreadTicks : public time_internal::TimeBase<ThreadTicks> { - public: - ThreadTicks() : TimeBase(0) { - } - - // Returns true if ThreadTicks::Now() is supported on this system. - static bool IsSupported() { -#if (defined(_POSIX_THREAD_CPUTIME) && (_POSIX_THREAD_CPUTIME >= 0)) || \ - (defined(OS_MACOSX) && !defined(OS_IOS)) || defined(OS_ANDROID) - return true; -#elif defined(OS_WIN) - return IsSupportedWin(); -#else - return false; -#endif - } - - // Waits until the initialization is completed. Needs to be guarded with a - // call to IsSupported(). - static void WaitUntilInitialized() { -#if defined(OS_WIN) - WaitUntilInitializedWin(); -#endif - } - - // Returns thread-specific CPU-time on systems that support this feature. - // Needs to be guarded with a call to IsSupported(). Use this timer - // to (approximately) measure how much time the calling thread spent doing - // actual work vs. being de-scheduled. May return bogus results if the thread - // migrates to another CPU between two calls. Returns an empty ThreadTicks - // object until the initialization is completed. If a clock reading is - // absolutely needed, call WaitUntilInitialized() before this method. - static ThreadTicks Now(); - - private: - friend class time_internal::TimeBase<ThreadTicks>; - - // Please use Now() to create a new object. This is for internal use - // and testing. - explicit ThreadTicks(int64_t us) : TimeBase(us) {} - -#if defined(OS_WIN) - FRIEND_TEST_ALL_PREFIXES(TimeTicks, TSCTicksPerSecond); - - // Returns the frequency of the TSC in ticks per second, or 0 if it hasn't - // been measured yet. Needs to be guarded with a call to IsSupported(). - // This method is declared here rather than in the anonymous namespace to - // allow testing. - static double TSCTicksPerSecond(); - - static bool IsSupportedWin(); - static void WaitUntilInitializedWin(); -#endif -}; - -// For logging use only. -BASE_EXPORT std::ostream& operator<<(std::ostream& os, ThreadTicks time_ticks); - -} // namespace base - -#endif // BASE_TIME_TIME_H_ |