Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 1 | // Copyright 2013 the V8 project authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | #ifndef V8_BASE_PLATFORM_TIME_H_ |
| 6 | #define V8_BASE_PLATFORM_TIME_H_ |
| 7 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 8 | #include <ctime> |
| 9 | #include <iosfwd> |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 10 | #include <limits> |
| 11 | |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame^] | 12 | #include "src/base/bits.h" |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 13 | #include "src/base/macros.h" |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame^] | 14 | #include "src/base/safe_math.h" |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 15 | |
| 16 | // Forward declarations. |
| 17 | extern "C" { |
| 18 | struct _FILETIME; |
| 19 | struct mach_timespec; |
| 20 | struct timespec; |
| 21 | struct timeval; |
| 22 | } |
| 23 | |
| 24 | namespace v8 { |
| 25 | namespace base { |
| 26 | |
| 27 | class Time; |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame^] | 28 | class TimeDelta; |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 29 | class TimeTicks; |
| 30 | |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame^] | 31 | namespace time_internal { |
| 32 | template<class TimeClass> |
| 33 | class TimeBase; |
| 34 | } |
| 35 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 36 | // ----------------------------------------------------------------------------- |
| 37 | // TimeDelta |
| 38 | // |
| 39 | // This class represents a duration of time, internally represented in |
| 40 | // microseonds. |
| 41 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 42 | class TimeDelta final { |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 43 | public: |
| 44 | TimeDelta() : delta_(0) {} |
| 45 | |
| 46 | // Converts units of time to TimeDeltas. |
| 47 | static TimeDelta FromDays(int days); |
| 48 | static TimeDelta FromHours(int hours); |
| 49 | static TimeDelta FromMinutes(int minutes); |
| 50 | static TimeDelta FromSeconds(int64_t seconds); |
| 51 | static TimeDelta FromMilliseconds(int64_t milliseconds); |
| 52 | static TimeDelta FromMicroseconds(int64_t microseconds) { |
| 53 | return TimeDelta(microseconds); |
| 54 | } |
| 55 | static TimeDelta FromNanoseconds(int64_t nanoseconds); |
| 56 | |
| 57 | // Returns the time delta in some unit. The F versions return a floating |
| 58 | // point value, the "regular" versions return a rounded-down value. |
| 59 | // |
| 60 | // InMillisecondsRoundedUp() instead returns an integer that is rounded up |
| 61 | // to the next full millisecond. |
| 62 | int InDays() const; |
| 63 | int InHours() const; |
| 64 | int InMinutes() const; |
| 65 | double InSecondsF() const; |
| 66 | int64_t InSeconds() const; |
| 67 | double InMillisecondsF() const; |
| 68 | int64_t InMilliseconds() const; |
| 69 | int64_t InMillisecondsRoundedUp() const; |
| 70 | int64_t InMicroseconds() const { return delta_; } |
| 71 | int64_t InNanoseconds() const; |
| 72 | |
| 73 | // Converts to/from Mach time specs. |
| 74 | static TimeDelta FromMachTimespec(struct mach_timespec ts); |
| 75 | struct mach_timespec ToMachTimespec() const; |
| 76 | |
| 77 | // Converts to/from POSIX time specs. |
| 78 | static TimeDelta FromTimespec(struct timespec ts); |
| 79 | struct timespec ToTimespec() const; |
| 80 | |
| 81 | TimeDelta& operator=(const TimeDelta& other) { |
| 82 | delta_ = other.delta_; |
| 83 | return *this; |
| 84 | } |
| 85 | |
| 86 | // Computations with other deltas. |
| 87 | TimeDelta operator+(const TimeDelta& other) const { |
| 88 | return TimeDelta(delta_ + other.delta_); |
| 89 | } |
| 90 | TimeDelta operator-(const TimeDelta& other) const { |
| 91 | return TimeDelta(delta_ - other.delta_); |
| 92 | } |
| 93 | |
| 94 | TimeDelta& operator+=(const TimeDelta& other) { |
| 95 | delta_ += other.delta_; |
| 96 | return *this; |
| 97 | } |
| 98 | TimeDelta& operator-=(const TimeDelta& other) { |
| 99 | delta_ -= other.delta_; |
| 100 | return *this; |
| 101 | } |
| 102 | TimeDelta operator-() const { |
| 103 | return TimeDelta(-delta_); |
| 104 | } |
| 105 | |
| 106 | double TimesOf(const TimeDelta& other) const { |
| 107 | return static_cast<double>(delta_) / static_cast<double>(other.delta_); |
| 108 | } |
| 109 | double PercentOf(const TimeDelta& other) const { |
| 110 | return TimesOf(other) * 100.0; |
| 111 | } |
| 112 | |
| 113 | // Computations with ints, note that we only allow multiplicative operations |
| 114 | // with ints, and additive operations with other deltas. |
| 115 | TimeDelta operator*(int64_t a) const { |
| 116 | return TimeDelta(delta_ * a); |
| 117 | } |
| 118 | TimeDelta operator/(int64_t a) const { |
| 119 | return TimeDelta(delta_ / a); |
| 120 | } |
| 121 | TimeDelta& operator*=(int64_t a) { |
| 122 | delta_ *= a; |
| 123 | return *this; |
| 124 | } |
| 125 | TimeDelta& operator/=(int64_t a) { |
| 126 | delta_ /= a; |
| 127 | return *this; |
| 128 | } |
| 129 | int64_t operator/(const TimeDelta& other) const { |
| 130 | return delta_ / other.delta_; |
| 131 | } |
| 132 | |
| 133 | // Comparison operators. |
| 134 | bool operator==(const TimeDelta& other) const { |
| 135 | return delta_ == other.delta_; |
| 136 | } |
| 137 | bool operator!=(const TimeDelta& other) const { |
| 138 | return delta_ != other.delta_; |
| 139 | } |
| 140 | bool operator<(const TimeDelta& other) const { |
| 141 | return delta_ < other.delta_; |
| 142 | } |
| 143 | bool operator<=(const TimeDelta& other) const { |
| 144 | return delta_ <= other.delta_; |
| 145 | } |
| 146 | bool operator>(const TimeDelta& other) const { |
| 147 | return delta_ > other.delta_; |
| 148 | } |
| 149 | bool operator>=(const TimeDelta& other) const { |
| 150 | return delta_ >= other.delta_; |
| 151 | } |
| 152 | |
| 153 | private: |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame^] | 154 | template<class TimeClass> friend class time_internal::TimeBase; |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 155 | // Constructs a delta given the duration in microseconds. This is private |
| 156 | // to avoid confusion by callers with an integer constructor. Use |
| 157 | // FromSeconds, FromMilliseconds, etc. instead. |
| 158 | explicit TimeDelta(int64_t delta) : delta_(delta) {} |
| 159 | |
| 160 | // Delta in microseconds. |
| 161 | int64_t delta_; |
| 162 | }; |
| 163 | |
| 164 | |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame^] | 165 | namespace time_internal { |
| 166 | |
| 167 | // TimeBase-------------------------------------------------------------------- |
| 168 | |
| 169 | // Provides value storage and comparison/math operations common to all time |
| 170 | // classes. Each subclass provides for strong type-checking to ensure |
| 171 | // semantically meaningful comparison/math of time values from the same clock |
| 172 | // source or timeline. |
| 173 | template<class TimeClass> |
| 174 | class TimeBase { |
| 175 | public: |
| 176 | static const int64_t kHoursPerDay = 24; |
| 177 | static const int64_t kMillisecondsPerSecond = 1000; |
| 178 | static const int64_t kMillisecondsPerDay = |
| 179 | kMillisecondsPerSecond * 60 * 60 * kHoursPerDay; |
| 180 | static const int64_t kMicrosecondsPerMillisecond = 1000; |
| 181 | static const int64_t kMicrosecondsPerSecond = |
| 182 | kMicrosecondsPerMillisecond * kMillisecondsPerSecond; |
| 183 | static const int64_t kMicrosecondsPerMinute = kMicrosecondsPerSecond * 60; |
| 184 | static const int64_t kMicrosecondsPerHour = kMicrosecondsPerMinute * 60; |
| 185 | static const int64_t kMicrosecondsPerDay = |
| 186 | kMicrosecondsPerHour * kHoursPerDay; |
| 187 | static const int64_t kMicrosecondsPerWeek = kMicrosecondsPerDay * 7; |
| 188 | static const int64_t kNanosecondsPerMicrosecond = 1000; |
| 189 | static const int64_t kNanosecondsPerSecond = |
| 190 | kNanosecondsPerMicrosecond * kMicrosecondsPerSecond; |
| 191 | |
| 192 | // Returns true if this object has not been initialized. |
| 193 | // |
| 194 | // Warning: Be careful when writing code that performs math on time values, |
| 195 | // since it's possible to produce a valid "zero" result that should not be |
| 196 | // interpreted as a "null" value. |
| 197 | bool IsNull() const { |
| 198 | return us_ == 0; |
| 199 | } |
| 200 | |
| 201 | // Returns true if this object represents the maximum time. |
| 202 | bool IsMax() const { return us_ == std::numeric_limits<int64_t>::max(); } |
| 203 | |
| 204 | // For serializing only. Use FromInternalValue() to reconstitute. Please don't |
| 205 | // use this and do arithmetic on it, as it is more error prone than using the |
| 206 | // provided operators. |
| 207 | int64_t ToInternalValue() const { return us_; } |
| 208 | |
| 209 | TimeClass& operator=(TimeClass other) { |
| 210 | us_ = other.us_; |
| 211 | return *(static_cast<TimeClass*>(this)); |
| 212 | } |
| 213 | |
| 214 | // Compute the difference between two times. |
| 215 | TimeDelta operator-(TimeClass other) const { |
| 216 | return TimeDelta::FromMicroseconds(us_ - other.us_); |
| 217 | } |
| 218 | |
| 219 | // Return a new time modified by some delta. |
| 220 | TimeClass operator+(TimeDelta delta) const { |
| 221 | return TimeClass(bits::SignedSaturatedAdd64(delta.delta_, us_)); |
| 222 | } |
| 223 | TimeClass operator-(TimeDelta delta) const { |
| 224 | return TimeClass(-bits::SignedSaturatedSub64(delta.delta_, us_)); |
| 225 | } |
| 226 | |
| 227 | // Modify by some time delta. |
| 228 | TimeClass& operator+=(TimeDelta delta) { |
| 229 | return static_cast<TimeClass&>(*this = (*this + delta)); |
| 230 | } |
| 231 | TimeClass& operator-=(TimeDelta delta) { |
| 232 | return static_cast<TimeClass&>(*this = (*this - delta)); |
| 233 | } |
| 234 | |
| 235 | // Comparison operators |
| 236 | bool operator==(TimeClass other) const { |
| 237 | return us_ == other.us_; |
| 238 | } |
| 239 | bool operator!=(TimeClass other) const { |
| 240 | return us_ != other.us_; |
| 241 | } |
| 242 | bool operator<(TimeClass other) const { |
| 243 | return us_ < other.us_; |
| 244 | } |
| 245 | bool operator<=(TimeClass other) const { |
| 246 | return us_ <= other.us_; |
| 247 | } |
| 248 | bool operator>(TimeClass other) const { |
| 249 | return us_ > other.us_; |
| 250 | } |
| 251 | bool operator>=(TimeClass other) const { |
| 252 | return us_ >= other.us_; |
| 253 | } |
| 254 | |
| 255 | // Converts an integer value representing TimeClass to a class. This is used |
| 256 | // when deserializing a |TimeClass| structure, using a value known to be |
| 257 | // compatible. It is not provided as a constructor because the integer type |
| 258 | // may be unclear from the perspective of a caller. |
| 259 | static TimeClass FromInternalValue(int64_t us) { return TimeClass(us); } |
| 260 | |
| 261 | protected: |
| 262 | explicit TimeBase(int64_t us) : us_(us) {} |
| 263 | |
| 264 | // Time value in a microsecond timebase. |
| 265 | int64_t us_; |
| 266 | }; |
| 267 | |
| 268 | } // namespace time_internal |
| 269 | |
| 270 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 271 | // ----------------------------------------------------------------------------- |
| 272 | // Time |
| 273 | // |
| 274 | // This class represents an absolute point in time, internally represented as |
| 275 | // microseconds (s/1,000,000) since 00:00:00 UTC, January 1, 1970. |
| 276 | |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame^] | 277 | class Time final : public time_internal::TimeBase<Time> { |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 278 | public: |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 279 | // Contains the NULL time. Use Time::Now() to get the current time. |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame^] | 280 | Time() : TimeBase(0) {} |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 281 | |
| 282 | // Returns the current time. Watch out, the system might adjust its clock |
| 283 | // in which case time will actually go backwards. We don't guarantee that |
| 284 | // times are increasing, or that two calls to Now() won't be the same. |
| 285 | static Time Now(); |
| 286 | |
| 287 | // Returns the current time. Same as Now() except that this function always |
| 288 | // uses system time so that there are no discrepancies between the returned |
| 289 | // time and system time even on virtual environments including our test bot. |
| 290 | // For timing sensitive unittests, this function should be used. |
| 291 | static Time NowFromSystemTime(); |
| 292 | |
| 293 | // Returns the time for epoch in Unix-like system (Jan 1, 1970). |
| 294 | static Time UnixEpoch() { return Time(0); } |
| 295 | |
| 296 | // Returns the maximum time, which should be greater than any reasonable time |
| 297 | // with which we might compare it. |
| 298 | static Time Max() { return Time(std::numeric_limits<int64_t>::max()); } |
| 299 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 300 | // Converts to/from POSIX time specs. |
| 301 | static Time FromTimespec(struct timespec ts); |
| 302 | struct timespec ToTimespec() const; |
| 303 | |
| 304 | // Converts to/from POSIX time values. |
| 305 | static Time FromTimeval(struct timeval tv); |
| 306 | struct timeval ToTimeval() const; |
| 307 | |
| 308 | // Converts to/from Windows file times. |
| 309 | static Time FromFiletime(struct _FILETIME ft); |
| 310 | struct _FILETIME ToFiletime() const; |
| 311 | |
| 312 | // Converts to/from the Javascript convention for times, a number of |
| 313 | // milliseconds since the epoch: |
| 314 | static Time FromJsTime(double ms_since_epoch); |
| 315 | double ToJsTime() const; |
| 316 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 317 | private: |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame^] | 318 | friend class time_internal::TimeBase<Time>; |
| 319 | explicit Time(int64_t us) : TimeBase(us) {} |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 320 | }; |
| 321 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 322 | std::ostream& operator<<(std::ostream&, const Time&); |
| 323 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 324 | inline Time operator+(const TimeDelta& delta, const Time& time) { |
| 325 | return time + delta; |
| 326 | } |
| 327 | |
| 328 | |
| 329 | // ----------------------------------------------------------------------------- |
| 330 | // TimeTicks |
| 331 | // |
| 332 | // This class represents an abstract time that is most of the time incrementing |
| 333 | // for use in measuring time durations. It is internally represented in |
| 334 | // microseconds. It can not be converted to a human-readable time, but is |
| 335 | // guaranteed not to decrease (if the user changes the computer clock, |
| 336 | // Time::Now() may actually decrease or jump). But note that TimeTicks may |
| 337 | // "stand still", for example if the computer suspended. |
| 338 | |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame^] | 339 | class TimeTicks final : public time_internal::TimeBase<TimeTicks> { |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 340 | public: |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame^] | 341 | TimeTicks() : TimeBase(0) {} |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 342 | |
| 343 | // Platform-dependent tick count representing "right now." |
| 344 | // The resolution of this clock is ~1-15ms. Resolution varies depending |
| 345 | // on hardware/operating system configuration. |
| 346 | // This method never returns a null TimeTicks. |
| 347 | static TimeTicks Now(); |
| 348 | |
| 349 | // Returns a platform-dependent high-resolution tick count. Implementation |
| 350 | // is hardware dependent and may or may not return sub-millisecond |
| 351 | // resolution. THIS CALL IS GENERALLY MUCH MORE EXPENSIVE THAN Now() AND |
| 352 | // SHOULD ONLY BE USED WHEN IT IS REALLY NEEDED. |
| 353 | // This method never returns a null TimeTicks. |
| 354 | static TimeTicks HighResolutionNow(); |
| 355 | |
| 356 | // Returns true if the high-resolution clock is working on this system. |
| 357 | static bool IsHighResolutionClockWorking(); |
| 358 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 359 | private: |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame^] | 360 | friend class time_internal::TimeBase<TimeTicks>; |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 361 | |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame^] | 362 | // Please use Now() to create a new object. This is for internal use |
| 363 | // and testing. Ticks are in microseconds. |
| 364 | explicit TimeTicks(int64_t ticks) : TimeBase(ticks) {} |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 365 | }; |
| 366 | |
| 367 | inline TimeTicks operator+(const TimeDelta& delta, const TimeTicks& ticks) { |
| 368 | return ticks + delta; |
| 369 | } |
| 370 | |
Ben Murdoch | c561043 | 2016-08-08 18:44:38 +0100 | [diff] [blame^] | 371 | |
| 372 | // ThreadTicks ---------------------------------------------------------------- |
| 373 | |
| 374 | // Represents a clock, specific to a particular thread, than runs only while the |
| 375 | // thread is running. |
| 376 | class ThreadTicks final : public time_internal::TimeBase<ThreadTicks> { |
| 377 | public: |
| 378 | ThreadTicks() : TimeBase(0) {} |
| 379 | |
| 380 | // Returns true if ThreadTicks::Now() is supported on this system. |
| 381 | static bool IsSupported(); |
| 382 | |
| 383 | // Returns thread-specific CPU-time on systems that support this feature. |
| 384 | // Needs to be guarded with a call to IsSupported(). Use this timer |
| 385 | // to (approximately) measure how much time the calling thread spent doing |
| 386 | // actual work vs. being de-scheduled. May return bogus results if the thread |
| 387 | // migrates to another CPU between two calls. Returns an empty ThreadTicks |
| 388 | // object until the initialization is completed. |
| 389 | static ThreadTicks Now(); |
| 390 | |
| 391 | private: |
| 392 | // This is for internal use and testing. Ticks are in microseconds. |
| 393 | explicit ThreadTicks(int64_t ticks) : TimeBase(ticks) {} |
| 394 | }; |
| 395 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 396 | } // namespace base |
| 397 | } // namespace v8 |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 398 | |
| 399 | #endif // V8_BASE_PLATFORM_TIME_H_ |