1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/security/sandbox/chromium/base/time/time.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,682 @@
1.4 +// Copyright (c) 2012 The Chromium Authors. All rights reserved.
1.5 +// Use of this source code is governed by a BSD-style license that can be
1.6 +// found in the LICENSE file.
1.7 +
1.8 +// Time represents an absolute point in time, internally represented as
1.9 +// microseconds (s/1,000,000) since the Windows epoch (1601-01-01 00:00:00 UTC)
1.10 +// (See http://crbug.com/14734). System-dependent clock interface routines are
1.11 +// defined in time_PLATFORM.cc.
1.12 +//
1.13 +// TimeDelta represents a duration of time, internally represented in
1.14 +// microseconds.
1.15 +//
1.16 +// TimeTicks represents an abstract time that is most of the time incrementing
1.17 +// for use in measuring time durations. It is internally represented in
1.18 +// microseconds. It can not be converted to a human-readable time, but is
1.19 +// guaranteed not to decrease (if the user changes the computer clock,
1.20 +// Time::Now() may actually decrease or jump). But note that TimeTicks may
1.21 +// "stand still", for example if the computer suspended.
1.22 +//
1.23 +// These classes are represented as only a 64-bit value, so they can be
1.24 +// efficiently passed by value.
1.25 +
1.26 +#ifndef BASE_TIME_TIME_H_
1.27 +#define BASE_TIME_TIME_H_
1.28 +
1.29 +#include <time.h>
1.30 +
1.31 +#include "base/base_export.h"
1.32 +#include "base/basictypes.h"
1.33 +#include "build/build_config.h"
1.34 +
1.35 +#if defined(OS_MACOSX)
1.36 +#include <CoreFoundation/CoreFoundation.h>
1.37 +// Avoid Mac system header macro leak.
1.38 +#undef TYPE_BOOL
1.39 +#endif
1.40 +
1.41 +#if defined(OS_POSIX)
1.42 +#include <unistd.h>
1.43 +#include <sys/time.h>
1.44 +#endif
1.45 +
1.46 +#if defined(OS_WIN)
1.47 +// For FILETIME in FromFileTime, until it moves to a new converter class.
1.48 +// See TODO(iyengar) below.
1.49 +#include <windows.h>
1.50 +#endif
1.51 +
1.52 +#include <limits>
1.53 +
1.54 +namespace base {
1.55 +
1.56 +class Time;
1.57 +class TimeTicks;
1.58 +
1.59 +// TimeDelta ------------------------------------------------------------------
1.60 +
1.61 +class BASE_EXPORT TimeDelta {
1.62 + public:
1.63 + TimeDelta() : delta_(0) {
1.64 + }
1.65 +
1.66 + // Converts units of time to TimeDeltas.
1.67 + static TimeDelta FromDays(int64 days);
1.68 + static TimeDelta FromHours(int64 hours);
1.69 + static TimeDelta FromMinutes(int64 minutes);
1.70 + static TimeDelta FromSeconds(int64 secs);
1.71 + static TimeDelta FromMilliseconds(int64 ms);
1.72 + static TimeDelta FromMicroseconds(int64 us);
1.73 +#if defined(OS_WIN)
1.74 + static TimeDelta FromQPCValue(LONGLONG qpc_value);
1.75 +#endif
1.76 +
1.77 + // Converts an integer value representing TimeDelta to a class. This is used
1.78 + // when deserializing a |TimeDelta| structure, using a value known to be
1.79 + // compatible. It is not provided as a constructor because the integer type
1.80 + // may be unclear from the perspective of a caller.
1.81 + static TimeDelta FromInternalValue(int64 delta) {
1.82 + return TimeDelta(delta);
1.83 + }
1.84 +
1.85 + // Returns the internal numeric value of the TimeDelta object. Please don't
1.86 + // use this and do arithmetic on it, as it is more error prone than using the
1.87 + // provided operators.
1.88 + // For serializing, use FromInternalValue to reconstitute.
1.89 + int64 ToInternalValue() const {
1.90 + return delta_;
1.91 + }
1.92 +
1.93 +#if defined(OS_POSIX)
1.94 + struct timespec ToTimeSpec() const;
1.95 +#endif
1.96 +
1.97 + // Returns the time delta in some unit. The F versions return a floating
1.98 + // point value, the "regular" versions return a rounded-down value.
1.99 + //
1.100 + // InMillisecondsRoundedUp() instead returns an integer that is rounded up
1.101 + // to the next full millisecond.
1.102 + int InDays() const;
1.103 + int InHours() const;
1.104 + int InMinutes() const;
1.105 + double InSecondsF() const;
1.106 + int64 InSeconds() const;
1.107 + double InMillisecondsF() const;
1.108 + int64 InMilliseconds() const;
1.109 + int64 InMillisecondsRoundedUp() const;
1.110 + int64 InMicroseconds() const;
1.111 +
1.112 + TimeDelta& operator=(TimeDelta other) {
1.113 + delta_ = other.delta_;
1.114 + return *this;
1.115 + }
1.116 +
1.117 + // Computations with other deltas.
1.118 + TimeDelta operator+(TimeDelta other) const {
1.119 + return TimeDelta(delta_ + other.delta_);
1.120 + }
1.121 + TimeDelta operator-(TimeDelta other) const {
1.122 + return TimeDelta(delta_ - other.delta_);
1.123 + }
1.124 +
1.125 + TimeDelta& operator+=(TimeDelta other) {
1.126 + delta_ += other.delta_;
1.127 + return *this;
1.128 + }
1.129 + TimeDelta& operator-=(TimeDelta other) {
1.130 + delta_ -= other.delta_;
1.131 + return *this;
1.132 + }
1.133 + TimeDelta operator-() const {
1.134 + return TimeDelta(-delta_);
1.135 + }
1.136 +
1.137 + // Computations with ints, note that we only allow multiplicative operations
1.138 + // with ints, and additive operations with other deltas.
1.139 + TimeDelta operator*(int64 a) const {
1.140 + return TimeDelta(delta_ * a);
1.141 + }
1.142 + TimeDelta operator/(int64 a) const {
1.143 + return TimeDelta(delta_ / a);
1.144 + }
1.145 + TimeDelta& operator*=(int64 a) {
1.146 + delta_ *= a;
1.147 + return *this;
1.148 + }
1.149 + TimeDelta& operator/=(int64 a) {
1.150 + delta_ /= a;
1.151 + return *this;
1.152 + }
1.153 + int64 operator/(TimeDelta a) const {
1.154 + return delta_ / a.delta_;
1.155 + }
1.156 +
1.157 + // Defined below because it depends on the definition of the other classes.
1.158 + Time operator+(Time t) const;
1.159 + TimeTicks operator+(TimeTicks t) const;
1.160 +
1.161 + // Comparison operators.
1.162 + bool operator==(TimeDelta other) const {
1.163 + return delta_ == other.delta_;
1.164 + }
1.165 + bool operator!=(TimeDelta other) const {
1.166 + return delta_ != other.delta_;
1.167 + }
1.168 + bool operator<(TimeDelta other) const {
1.169 + return delta_ < other.delta_;
1.170 + }
1.171 + bool operator<=(TimeDelta other) const {
1.172 + return delta_ <= other.delta_;
1.173 + }
1.174 + bool operator>(TimeDelta other) const {
1.175 + return delta_ > other.delta_;
1.176 + }
1.177 + bool operator>=(TimeDelta other) const {
1.178 + return delta_ >= other.delta_;
1.179 + }
1.180 +
1.181 + private:
1.182 + friend class Time;
1.183 + friend class TimeTicks;
1.184 + friend TimeDelta operator*(int64 a, TimeDelta td);
1.185 +
1.186 + // Constructs a delta given the duration in microseconds. This is private
1.187 + // to avoid confusion by callers with an integer constructor. Use
1.188 + // FromSeconds, FromMilliseconds, etc. instead.
1.189 + explicit TimeDelta(int64 delta_us) : delta_(delta_us) {
1.190 + }
1.191 +
1.192 + // Delta in microseconds.
1.193 + int64 delta_;
1.194 +};
1.195 +
1.196 +inline TimeDelta operator*(int64 a, TimeDelta td) {
1.197 + return TimeDelta(a * td.delta_);
1.198 +}
1.199 +
1.200 +// Time -----------------------------------------------------------------------
1.201 +
1.202 +// Represents a wall clock time.
1.203 +class BASE_EXPORT Time {
1.204 + public:
1.205 + static const int64 kMillisecondsPerSecond = 1000;
1.206 + static const int64 kMicrosecondsPerMillisecond = 1000;
1.207 + static const int64 kMicrosecondsPerSecond = kMicrosecondsPerMillisecond *
1.208 + kMillisecondsPerSecond;
1.209 + static const int64 kMicrosecondsPerMinute = kMicrosecondsPerSecond * 60;
1.210 + static const int64 kMicrosecondsPerHour = kMicrosecondsPerMinute * 60;
1.211 + static const int64 kMicrosecondsPerDay = kMicrosecondsPerHour * 24;
1.212 + static const int64 kMicrosecondsPerWeek = kMicrosecondsPerDay * 7;
1.213 + static const int64 kNanosecondsPerMicrosecond = 1000;
1.214 + static const int64 kNanosecondsPerSecond = kNanosecondsPerMicrosecond *
1.215 + kMicrosecondsPerSecond;
1.216 +
1.217 +#if !defined(OS_WIN)
1.218 + // On Mac & Linux, this value is the delta from the Windows epoch of 1601 to
1.219 + // the Posix delta of 1970. This is used for migrating between the old
1.220 + // 1970-based epochs to the new 1601-based ones. It should be removed from
1.221 + // this global header and put in the platform-specific ones when we remove the
1.222 + // migration code.
1.223 + static const int64 kWindowsEpochDeltaMicroseconds;
1.224 +#endif
1.225 +
1.226 + // Represents an exploded time that can be formatted nicely. This is kind of
1.227 + // like the Win32 SYSTEMTIME structure or the Unix "struct tm" with a few
1.228 + // additions and changes to prevent errors.
1.229 + struct BASE_EXPORT Exploded {
1.230 + int year; // Four digit year "2007"
1.231 + int month; // 1-based month (values 1 = January, etc.)
1.232 + int day_of_week; // 0-based day of week (0 = Sunday, etc.)
1.233 + int day_of_month; // 1-based day of month (1-31)
1.234 + int hour; // Hour within the current day (0-23)
1.235 + int minute; // Minute within the current hour (0-59)
1.236 + int second; // Second within the current minute (0-59 plus leap
1.237 + // seconds which may take it up to 60).
1.238 + int millisecond; // Milliseconds within the current second (0-999)
1.239 +
1.240 + // A cursory test for whether the data members are within their
1.241 + // respective ranges. A 'true' return value does not guarantee the
1.242 + // Exploded value can be successfully converted to a Time value.
1.243 + bool HasValidValues() const;
1.244 + };
1.245 +
1.246 + // Contains the NULL time. Use Time::Now() to get the current time.
1.247 + Time() : us_(0) {
1.248 + }
1.249 +
1.250 + // Returns true if the time object has not been initialized.
1.251 + bool is_null() const {
1.252 + return us_ == 0;
1.253 + }
1.254 +
1.255 + // Returns true if the time object is the maximum time.
1.256 + bool is_max() const {
1.257 + return us_ == std::numeric_limits<int64>::max();
1.258 + }
1.259 +
1.260 + // Returns the time for epoch in Unix-like system (Jan 1, 1970).
1.261 + static Time UnixEpoch();
1.262 +
1.263 + // Returns the current time. Watch out, the system might adjust its clock
1.264 + // in which case time will actually go backwards. We don't guarantee that
1.265 + // times are increasing, or that two calls to Now() won't be the same.
1.266 + static Time Now();
1.267 +
1.268 + // Returns the maximum time, which should be greater than any reasonable time
1.269 + // with which we might compare it.
1.270 + static Time Max();
1.271 +
1.272 + // Returns the current time. Same as Now() except that this function always
1.273 + // uses system time so that there are no discrepancies between the returned
1.274 + // time and system time even on virtual environments including our test bot.
1.275 + // For timing sensitive unittests, this function should be used.
1.276 + static Time NowFromSystemTime();
1.277 +
1.278 + // Converts to/from time_t in UTC and a Time class.
1.279 + // TODO(brettw) this should be removed once everybody starts using the |Time|
1.280 + // class.
1.281 + static Time FromTimeT(time_t tt);
1.282 + time_t ToTimeT() const;
1.283 +
1.284 + // Converts time to/from a double which is the number of seconds since epoch
1.285 + // (Jan 1, 1970). Webkit uses this format to represent time.
1.286 + // Because WebKit initializes double time value to 0 to indicate "not
1.287 + // initialized", we map it to empty Time object that also means "not
1.288 + // initialized".
1.289 + static Time FromDoubleT(double dt);
1.290 + double ToDoubleT() const;
1.291 +
1.292 +#if defined(OS_POSIX)
1.293 + // Converts the timespec structure to time. MacOS X 10.8.3 (and tentatively,
1.294 + // earlier versions) will have the |ts|'s tv_nsec component zeroed out,
1.295 + // having a 1 second resolution, which agrees with
1.296 + // https://developer.apple.com/legacy/library/#technotes/tn/tn1150.html#HFSPlusDates.
1.297 + static Time FromTimeSpec(const timespec& ts);
1.298 +#endif
1.299 +
1.300 + // Converts to/from the Javascript convention for times, a number of
1.301 + // milliseconds since the epoch:
1.302 + // https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Date/getTime.
1.303 + static Time FromJsTime(double ms_since_epoch);
1.304 + double ToJsTime() const;
1.305 +
1.306 + // Converts to Java convention for times, a number of
1.307 + // milliseconds since the epoch.
1.308 + int64 ToJavaTime() const;
1.309 +
1.310 +#if defined(OS_POSIX)
1.311 + static Time FromTimeVal(struct timeval t);
1.312 + struct timeval ToTimeVal() const;
1.313 +#endif
1.314 +
1.315 +#if defined(OS_MACOSX)
1.316 + static Time FromCFAbsoluteTime(CFAbsoluteTime t);
1.317 + CFAbsoluteTime ToCFAbsoluteTime() const;
1.318 +#endif
1.319 +
1.320 +#if defined(OS_WIN)
1.321 + static Time FromFileTime(FILETIME ft);
1.322 + FILETIME ToFileTime() const;
1.323 +
1.324 + // The minimum time of a low resolution timer. This is basically a windows
1.325 + // constant of ~15.6ms. While it does vary on some older OS versions, we'll
1.326 + // treat it as static across all windows versions.
1.327 + static const int kMinLowResolutionThresholdMs = 16;
1.328 +
1.329 + // Enable or disable Windows high resolution timer. If the high resolution
1.330 + // timer is not enabled, calls to ActivateHighResolutionTimer will fail.
1.331 + // When disabling the high resolution timer, this function will not cause
1.332 + // the high resolution timer to be deactivated, but will prevent future
1.333 + // activations.
1.334 + // Must be called from the main thread.
1.335 + // For more details see comments in time_win.cc.
1.336 + static void EnableHighResolutionTimer(bool enable);
1.337 +
1.338 + // Activates or deactivates the high resolution timer based on the |activate|
1.339 + // flag. If the HighResolutionTimer is not Enabled (see
1.340 + // EnableHighResolutionTimer), this function will return false. Otherwise
1.341 + // returns true. Each successful activate call must be paired with a
1.342 + // subsequent deactivate call.
1.343 + // All callers to activate the high resolution timer must eventually call
1.344 + // this function to deactivate the high resolution timer.
1.345 + static bool ActivateHighResolutionTimer(bool activate);
1.346 +
1.347 + // Returns true if the high resolution timer is both enabled and activated.
1.348 + // This is provided for testing only, and is not tracked in a thread-safe
1.349 + // way.
1.350 + static bool IsHighResolutionTimerInUse();
1.351 +#endif
1.352 +
1.353 + // Converts an exploded structure representing either the local time or UTC
1.354 + // into a Time class.
1.355 + static Time FromUTCExploded(const Exploded& exploded) {
1.356 + return FromExploded(false, exploded);
1.357 + }
1.358 + static Time FromLocalExploded(const Exploded& exploded) {
1.359 + return FromExploded(true, exploded);
1.360 + }
1.361 +
1.362 + // Converts an integer value representing Time to a class. This is used
1.363 + // when deserializing a |Time| structure, using a value known to be
1.364 + // compatible. It is not provided as a constructor because the integer type
1.365 + // may be unclear from the perspective of a caller.
1.366 + static Time FromInternalValue(int64 us) {
1.367 + return Time(us);
1.368 + }
1.369 +
1.370 + // Converts a string representation of time to a Time object.
1.371 + // An example of a time string which is converted is as below:-
1.372 + // "Tue, 15 Nov 1994 12:45:26 GMT". If the timezone is not specified
1.373 + // in the input string, FromString assumes local time and FromUTCString
1.374 + // assumes UTC. A timezone that cannot be parsed (e.g. "UTC" which is not
1.375 + // specified in RFC822) is treated as if the timezone is not specified.
1.376 + // TODO(iyengar) Move the FromString/FromTimeT/ToTimeT/FromFileTime to
1.377 + // a new time converter class.
1.378 + static bool FromString(const char* time_string, Time* parsed_time) {
1.379 + return FromStringInternal(time_string, true, parsed_time);
1.380 + }
1.381 + static bool FromUTCString(const char* time_string, Time* parsed_time) {
1.382 + return FromStringInternal(time_string, false, parsed_time);
1.383 + }
1.384 +
1.385 + // For serializing, use FromInternalValue to reconstitute. Please don't use
1.386 + // this and do arithmetic on it, as it is more error prone than using the
1.387 + // provided operators.
1.388 + int64 ToInternalValue() const {
1.389 + return us_;
1.390 + }
1.391 +
1.392 + // Fills the given exploded structure with either the local time or UTC from
1.393 + // this time structure (containing UTC).
1.394 + void UTCExplode(Exploded* exploded) const {
1.395 + return Explode(false, exploded);
1.396 + }
1.397 + void LocalExplode(Exploded* exploded) const {
1.398 + return Explode(true, exploded);
1.399 + }
1.400 +
1.401 + // Rounds this time down to the nearest day in local time. It will represent
1.402 + // midnight on that day.
1.403 + Time LocalMidnight() const;
1.404 +
1.405 + Time& operator=(Time other) {
1.406 + us_ = other.us_;
1.407 + return *this;
1.408 + }
1.409 +
1.410 + // Compute the difference between two times.
1.411 + TimeDelta operator-(Time other) const {
1.412 + return TimeDelta(us_ - other.us_);
1.413 + }
1.414 +
1.415 + // Modify by some time delta.
1.416 + Time& operator+=(TimeDelta delta) {
1.417 + us_ += delta.delta_;
1.418 + return *this;
1.419 + }
1.420 + Time& operator-=(TimeDelta delta) {
1.421 + us_ -= delta.delta_;
1.422 + return *this;
1.423 + }
1.424 +
1.425 + // Return a new time modified by some delta.
1.426 + Time operator+(TimeDelta delta) const {
1.427 + return Time(us_ + delta.delta_);
1.428 + }
1.429 + Time operator-(TimeDelta delta) const {
1.430 + return Time(us_ - delta.delta_);
1.431 + }
1.432 +
1.433 + // Comparison operators
1.434 + bool operator==(Time other) const {
1.435 + return us_ == other.us_;
1.436 + }
1.437 + bool operator!=(Time other) const {
1.438 + return us_ != other.us_;
1.439 + }
1.440 + bool operator<(Time other) const {
1.441 + return us_ < other.us_;
1.442 + }
1.443 + bool operator<=(Time other) const {
1.444 + return us_ <= other.us_;
1.445 + }
1.446 + bool operator>(Time other) const {
1.447 + return us_ > other.us_;
1.448 + }
1.449 + bool operator>=(Time other) const {
1.450 + return us_ >= other.us_;
1.451 + }
1.452 +
1.453 + private:
1.454 + friend class TimeDelta;
1.455 +
1.456 + explicit Time(int64 us) : us_(us) {
1.457 + }
1.458 +
1.459 + // Explodes the given time to either local time |is_local = true| or UTC
1.460 + // |is_local = false|.
1.461 + void Explode(bool is_local, Exploded* exploded) const;
1.462 +
1.463 + // Unexplodes a given time assuming the source is either local time
1.464 + // |is_local = true| or UTC |is_local = false|.
1.465 + static Time FromExploded(bool is_local, const Exploded& exploded);
1.466 +
1.467 + // Converts a string representation of time to a Time object.
1.468 + // An example of a time string which is converted is as below:-
1.469 + // "Tue, 15 Nov 1994 12:45:26 GMT". If the timezone is not specified
1.470 + // in the input string, local time |is_local = true| or
1.471 + // UTC |is_local = false| is assumed. A timezone that cannot be parsed
1.472 + // (e.g. "UTC" which is not specified in RFC822) is treated as if the
1.473 + // timezone is not specified.
1.474 + static bool FromStringInternal(const char* time_string,
1.475 + bool is_local,
1.476 + Time* parsed_time);
1.477 +
1.478 + // The representation of Jan 1, 1970 UTC in microseconds since the
1.479 + // platform-dependent epoch.
1.480 + static const int64 kTimeTToMicrosecondsOffset;
1.481 +
1.482 +#if defined(OS_WIN)
1.483 + // Indicates whether fast timers are usable right now. For instance,
1.484 + // when using battery power, we might elect to prevent high speed timers
1.485 + // which would draw more power.
1.486 + static bool high_resolution_timer_enabled_;
1.487 + // Count of activations on the high resolution timer. Only use in tests
1.488 + // which are single threaded.
1.489 + static int high_resolution_timer_activated_;
1.490 +#endif
1.491 +
1.492 + // Time in microseconds in UTC.
1.493 + int64 us_;
1.494 +};
1.495 +
1.496 +// Inline the TimeDelta factory methods, for fast TimeDelta construction.
1.497 +
1.498 +// static
1.499 +inline TimeDelta TimeDelta::FromDays(int64 days) {
1.500 + return TimeDelta(days * Time::kMicrosecondsPerDay);
1.501 +}
1.502 +
1.503 +// static
1.504 +inline TimeDelta TimeDelta::FromHours(int64 hours) {
1.505 + return TimeDelta(hours * Time::kMicrosecondsPerHour);
1.506 +}
1.507 +
1.508 +// static
1.509 +inline TimeDelta TimeDelta::FromMinutes(int64 minutes) {
1.510 + return TimeDelta(minutes * Time::kMicrosecondsPerMinute);
1.511 +}
1.512 +
1.513 +// static
1.514 +inline TimeDelta TimeDelta::FromSeconds(int64 secs) {
1.515 + return TimeDelta(secs * Time::kMicrosecondsPerSecond);
1.516 +}
1.517 +
1.518 +// static
1.519 +inline TimeDelta TimeDelta::FromMilliseconds(int64 ms) {
1.520 + return TimeDelta(ms * Time::kMicrosecondsPerMillisecond);
1.521 +}
1.522 +
1.523 +// static
1.524 +inline TimeDelta TimeDelta::FromMicroseconds(int64 us) {
1.525 + return TimeDelta(us);
1.526 +}
1.527 +
1.528 +inline Time TimeDelta::operator+(Time t) const {
1.529 + return Time(t.us_ + delta_);
1.530 +}
1.531 +
1.532 +// TimeTicks ------------------------------------------------------------------
1.533 +
1.534 +class BASE_EXPORT TimeTicks {
1.535 + public:
1.536 + TimeTicks() : ticks_(0) {
1.537 + }
1.538 +
1.539 + // Platform-dependent tick count representing "right now."
1.540 + // The resolution of this clock is ~1-15ms. Resolution varies depending
1.541 + // on hardware/operating system configuration.
1.542 + static TimeTicks Now();
1.543 +
1.544 + // Returns a platform-dependent high-resolution tick count. Implementation
1.545 + // is hardware dependent and may or may not return sub-millisecond
1.546 + // resolution. THIS CALL IS GENERALLY MUCH MORE EXPENSIVE THAN Now() AND
1.547 + // SHOULD ONLY BE USED WHEN IT IS REALLY NEEDED.
1.548 + static TimeTicks HighResNow();
1.549 +
1.550 + // Returns true if ThreadNow() is supported on this system.
1.551 + static bool IsThreadNowSupported() {
1.552 +#if defined(_POSIX_THREAD_CPUTIME) && (_POSIX_THREAD_CPUTIME >= 0)
1.553 + return true;
1.554 +#else
1.555 + return false;
1.556 +#endif
1.557 + }
1.558 +
1.559 + // Returns thread-specific CPU-time on systems that support this feature.
1.560 + // Needs to be guarded with a call to IsThreadNowSupported(). Use this timer
1.561 + // to (approximately) measure how much time the calling thread spent doing
1.562 + // actual work vs. being de-scheduled. May return bogus results if the thread
1.563 + // migrates to another CPU between two calls.
1.564 + static TimeTicks ThreadNow();
1.565 +
1.566 + // Returns the current system trace time or, if none is defined, the current
1.567 + // high-res time (i.e. HighResNow()). On systems where a global trace clock
1.568 + // is defined, timestamping TraceEvents's with this value guarantees
1.569 + // synchronization between events collected inside chrome and events
1.570 + // collected outside (e.g. kernel, X server).
1.571 + static TimeTicks NowFromSystemTraceTime();
1.572 +
1.573 +#if defined(OS_WIN)
1.574 + // Get the absolute value of QPC time drift. For testing.
1.575 + static int64 GetQPCDriftMicroseconds();
1.576 +
1.577 + static TimeTicks FromQPCValue(LONGLONG qpc_value);
1.578 +
1.579 + // Returns true if the high resolution clock is working on this system.
1.580 + // This is only for testing.
1.581 + static bool IsHighResClockWorking();
1.582 +
1.583 + // Enable high resolution time for TimeTicks::Now(). This function will
1.584 + // test for the availability of a working implementation of
1.585 + // QueryPerformanceCounter(). If one is not available, this function does
1.586 + // nothing and the resolution of Now() remains 1ms. Otherwise, all future
1.587 + // calls to TimeTicks::Now() will have the higher resolution provided by QPC.
1.588 + // Returns true if high resolution time was successfully enabled.
1.589 + static bool SetNowIsHighResNowIfSupported();
1.590 +
1.591 + // Returns a time value that is NOT rollover protected.
1.592 + static TimeTicks UnprotectedNow();
1.593 +#endif
1.594 +
1.595 + // Returns true if this object has not been initialized.
1.596 + bool is_null() const {
1.597 + return ticks_ == 0;
1.598 + }
1.599 +
1.600 + // Converts an integer value representing TimeTicks to a class. This is used
1.601 + // when deserializing a |TimeTicks| structure, using a value known to be
1.602 + // compatible. It is not provided as a constructor because the integer type
1.603 + // may be unclear from the perspective of a caller.
1.604 + static TimeTicks FromInternalValue(int64 ticks) {
1.605 + return TimeTicks(ticks);
1.606 + }
1.607 +
1.608 + // Returns the internal numeric value of the TimeTicks object.
1.609 + // For serializing, use FromInternalValue to reconstitute.
1.610 + int64 ToInternalValue() const {
1.611 + return ticks_;
1.612 + }
1.613 +
1.614 + TimeTicks& operator=(TimeTicks other) {
1.615 + ticks_ = other.ticks_;
1.616 + return *this;
1.617 + }
1.618 +
1.619 + // Compute the difference between two times.
1.620 + TimeDelta operator-(TimeTicks other) const {
1.621 + return TimeDelta(ticks_ - other.ticks_);
1.622 + }
1.623 +
1.624 + // Modify by some time delta.
1.625 + TimeTicks& operator+=(TimeDelta delta) {
1.626 + ticks_ += delta.delta_;
1.627 + return *this;
1.628 + }
1.629 + TimeTicks& operator-=(TimeDelta delta) {
1.630 + ticks_ -= delta.delta_;
1.631 + return *this;
1.632 + }
1.633 +
1.634 + // Return a new TimeTicks modified by some delta.
1.635 + TimeTicks operator+(TimeDelta delta) const {
1.636 + return TimeTicks(ticks_ + delta.delta_);
1.637 + }
1.638 + TimeTicks operator-(TimeDelta delta) const {
1.639 + return TimeTicks(ticks_ - delta.delta_);
1.640 + }
1.641 +
1.642 + // Comparison operators
1.643 + bool operator==(TimeTicks other) const {
1.644 + return ticks_ == other.ticks_;
1.645 + }
1.646 + bool operator!=(TimeTicks other) const {
1.647 + return ticks_ != other.ticks_;
1.648 + }
1.649 + bool operator<(TimeTicks other) const {
1.650 + return ticks_ < other.ticks_;
1.651 + }
1.652 + bool operator<=(TimeTicks other) const {
1.653 + return ticks_ <= other.ticks_;
1.654 + }
1.655 + bool operator>(TimeTicks other) const {
1.656 + return ticks_ > other.ticks_;
1.657 + }
1.658 + bool operator>=(TimeTicks other) const {
1.659 + return ticks_ >= other.ticks_;
1.660 + }
1.661 +
1.662 + protected:
1.663 + friend class TimeDelta;
1.664 +
1.665 + // Please use Now() to create a new object. This is for internal use
1.666 + // and testing. Ticks is in microseconds.
1.667 + explicit TimeTicks(int64 ticks) : ticks_(ticks) {
1.668 + }
1.669 +
1.670 + // Tick count in microseconds.
1.671 + int64 ticks_;
1.672 +
1.673 +#if defined(OS_WIN)
1.674 + typedef DWORD (*TickFunctionType)(void);
1.675 + static TickFunctionType SetMockTickFunction(TickFunctionType ticker);
1.676 +#endif
1.677 +};
1.678 +
1.679 +inline TimeTicks TimeDelta::operator+(TimeTicks t) const {
1.680 + return TimeTicks(t.ticks_ + delta_);
1.681 +}
1.682 +
1.683 +} // namespace base
1.684 +
1.685 +#endif // BASE_TIME_TIME_H_
