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
8#include <time.h>
9#include <limits>
10
11#include "src/base/macros.h"
12
13// Forward declarations.
14extern "C" {
15struct _FILETIME;
16struct mach_timespec;
17struct timespec;
18struct timeval;
19}
20
21namespace v8 {
22namespace base {
23
24class Time;
25class TimeTicks;
26
27// -----------------------------------------------------------------------------
28// TimeDelta
29//
30// This class represents a duration of time, internally represented in
31// microseonds.
32
33class TimeDelta FINAL {
34 public:
35  TimeDelta() : delta_(0) {}
36
37  // Converts units of time to TimeDeltas.
38  static TimeDelta FromDays(int days);
39  static TimeDelta FromHours(int hours);
40  static TimeDelta FromMinutes(int minutes);
41  static TimeDelta FromSeconds(int64_t seconds);
42  static TimeDelta FromMilliseconds(int64_t milliseconds);
43  static TimeDelta FromMicroseconds(int64_t microseconds) {
44    return TimeDelta(microseconds);
45  }
46  static TimeDelta FromNanoseconds(int64_t nanoseconds);
47
48  // Returns the time delta in some unit. The F versions return a floating
49  // point value, the "regular" versions return a rounded-down value.
50  //
51  // InMillisecondsRoundedUp() instead returns an integer that is rounded up
52  // to the next full millisecond.
53  int InDays() const;
54  int InHours() const;
55  int InMinutes() const;
56  double InSecondsF() const;
57  int64_t InSeconds() const;
58  double InMillisecondsF() const;
59  int64_t InMilliseconds() const;
60  int64_t InMillisecondsRoundedUp() const;
61  int64_t InMicroseconds() const { return delta_; }
62  int64_t InNanoseconds() const;
63
64  // Converts to/from Mach time specs.
65  static TimeDelta FromMachTimespec(struct mach_timespec ts);
66  struct mach_timespec ToMachTimespec() const;
67
68  // Converts to/from POSIX time specs.
69  static TimeDelta FromTimespec(struct timespec ts);
70  struct timespec ToTimespec() const;
71
72  TimeDelta& operator=(const TimeDelta& other) {
73    delta_ = other.delta_;
74    return *this;
75  }
76
77  // Computations with other deltas.
78  TimeDelta operator+(const TimeDelta& other) const {
79    return TimeDelta(delta_ + other.delta_);
80  }
81  TimeDelta operator-(const TimeDelta& other) const {
82    return TimeDelta(delta_ - other.delta_);
83  }
84
85  TimeDelta& operator+=(const TimeDelta& other) {
86    delta_ += other.delta_;
87    return *this;
88  }
89  TimeDelta& operator-=(const TimeDelta& other) {
90    delta_ -= other.delta_;
91    return *this;
92  }
93  TimeDelta operator-() const {
94    return TimeDelta(-delta_);
95  }
96
97  double TimesOf(const TimeDelta& other) const {
98    return static_cast<double>(delta_) / static_cast<double>(other.delta_);
99  }
100  double PercentOf(const TimeDelta& other) const {
101    return TimesOf(other) * 100.0;
102  }
103
104  // Computations with ints, note that we only allow multiplicative operations
105  // with ints, and additive operations with other deltas.
106  TimeDelta operator*(int64_t a) const {
107    return TimeDelta(delta_ * a);
108  }
109  TimeDelta operator/(int64_t a) const {
110    return TimeDelta(delta_ / a);
111  }
112  TimeDelta& operator*=(int64_t a) {
113    delta_ *= a;
114    return *this;
115  }
116  TimeDelta& operator/=(int64_t a) {
117    delta_ /= a;
118    return *this;
119  }
120  int64_t operator/(const TimeDelta& other) const {
121    return delta_ / other.delta_;
122  }
123
124  // Comparison operators.
125  bool operator==(const TimeDelta& other) const {
126    return delta_ == other.delta_;
127  }
128  bool operator!=(const TimeDelta& other) const {
129    return delta_ != other.delta_;
130  }
131  bool operator<(const TimeDelta& other) const {
132    return delta_ < other.delta_;
133  }
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
144 private:
145  // Constructs a delta given the duration in microseconds. This is private
146  // to avoid confusion by callers with an integer constructor. Use
147  // FromSeconds, FromMilliseconds, etc. instead.
148  explicit TimeDelta(int64_t delta) : delta_(delta) {}
149
150  // Delta in microseconds.
151  int64_t delta_;
152};
153
154
155// -----------------------------------------------------------------------------
156// Time
157//
158// This class represents an absolute point in time, internally represented as
159// microseconds (s/1,000,000) since 00:00:00 UTC, January 1, 1970.
160
161class Time FINAL {
162 public:
163  static const int64_t kMillisecondsPerSecond = 1000;
164  static const int64_t kMicrosecondsPerMillisecond = 1000;
165  static const int64_t kMicrosecondsPerSecond = kMicrosecondsPerMillisecond *
166                                                kMillisecondsPerSecond;
167  static const int64_t kMicrosecondsPerMinute = kMicrosecondsPerSecond * 60;
168  static const int64_t kMicrosecondsPerHour = kMicrosecondsPerMinute * 60;
169  static const int64_t kMicrosecondsPerDay = kMicrosecondsPerHour * 24;
170  static const int64_t kMicrosecondsPerWeek = kMicrosecondsPerDay * 7;
171  static const int64_t kNanosecondsPerMicrosecond = 1000;
172  static const int64_t kNanosecondsPerSecond = kNanosecondsPerMicrosecond *
173                                               kMicrosecondsPerSecond;
174
175  // Contains the NULL time. Use Time::Now() to get the current time.
176  Time() : us_(0) {}
177
178  // Returns true if the time object has not been initialized.
179  bool IsNull() const { return us_ == 0; }
180
181  // Returns true if the time object is the maximum time.
182  bool IsMax() const { return us_ == std::numeric_limits<int64_t>::max(); }
183
184  // Returns the current time. Watch out, the system might adjust its clock
185  // in which case time will actually go backwards. We don't guarantee that
186  // times are increasing, or that two calls to Now() won't be the same.
187  static Time Now();
188
189  // Returns the current time. Same as Now() except that this function always
190  // uses system time so that there are no discrepancies between the returned
191  // time and system time even on virtual environments including our test bot.
192  // For timing sensitive unittests, this function should be used.
193  static Time NowFromSystemTime();
194
195  // Returns the time for epoch in Unix-like system (Jan 1, 1970).
196  static Time UnixEpoch() { return Time(0); }
197
198  // Returns the maximum time, which should be greater than any reasonable time
199  // with which we might compare it.
200  static Time Max() { return Time(std::numeric_limits<int64_t>::max()); }
201
202  // Converts to/from internal values. The meaning of the "internal value" is
203  // completely up to the implementation, so it should be treated as opaque.
204  static Time FromInternalValue(int64_t value) {
205    return Time(value);
206  }
207  int64_t ToInternalValue() const {
208    return us_;
209  }
210
211  // Converts to/from POSIX time specs.
212  static Time FromTimespec(struct timespec ts);
213  struct timespec ToTimespec() const;
214
215  // Converts to/from POSIX time values.
216  static Time FromTimeval(struct timeval tv);
217  struct timeval ToTimeval() const;
218
219  // Converts to/from Windows file times.
220  static Time FromFiletime(struct _FILETIME ft);
221  struct _FILETIME ToFiletime() const;
222
223  // Converts to/from the Javascript convention for times, a number of
224  // milliseconds since the epoch:
225  static Time FromJsTime(double ms_since_epoch);
226  double ToJsTime() const;
227
228  Time& operator=(const Time& other) {
229    us_ = other.us_;
230    return *this;
231  }
232
233  // Compute the difference between two times.
234  TimeDelta operator-(const Time& other) const {
235    return TimeDelta::FromMicroseconds(us_ - other.us_);
236  }
237
238  // Modify by some time delta.
239  Time& operator+=(const TimeDelta& delta) {
240    us_ += delta.InMicroseconds();
241    return *this;
242  }
243  Time& operator-=(const TimeDelta& delta) {
244    us_ -= delta.InMicroseconds();
245    return *this;
246  }
247
248  // Return a new time modified by some delta.
249  Time operator+(const TimeDelta& delta) const {
250    return Time(us_ + delta.InMicroseconds());
251  }
252  Time operator-(const TimeDelta& delta) const {
253    return Time(us_ - delta.InMicroseconds());
254  }
255
256  // Comparison operators
257  bool operator==(const Time& other) const {
258    return us_ == other.us_;
259  }
260  bool operator!=(const Time& other) const {
261    return us_ != other.us_;
262  }
263  bool operator<(const Time& other) const {
264    return us_ < other.us_;
265  }
266  bool operator<=(const Time& other) const {
267    return us_ <= other.us_;
268  }
269  bool operator>(const Time& other) const {
270    return us_ > other.us_;
271  }
272  bool operator>=(const Time& other) const {
273    return us_ >= other.us_;
274  }
275
276 private:
277  explicit Time(int64_t us) : us_(us) {}
278
279  // Time in microseconds in UTC.
280  int64_t us_;
281};
282
283inline Time operator+(const TimeDelta& delta, const Time& time) {
284  return time + delta;
285}
286
287
288// -----------------------------------------------------------------------------
289// TimeTicks
290//
291// This class represents an abstract time that is most of the time incrementing
292// for use in measuring time durations. It is internally represented in
293// microseconds.  It can not be converted to a human-readable time, but is
294// guaranteed not to decrease (if the user changes the computer clock,
295// Time::Now() may actually decrease or jump).  But note that TimeTicks may
296// "stand still", for example if the computer suspended.
297
298class TimeTicks FINAL {
299 public:
300  TimeTicks() : ticks_(0) {}
301
302  // Platform-dependent tick count representing "right now."
303  // The resolution of this clock is ~1-15ms.  Resolution varies depending
304  // on hardware/operating system configuration.
305  // This method never returns a null TimeTicks.
306  static TimeTicks Now();
307
308  // Returns a platform-dependent high-resolution tick count. Implementation
309  // is hardware dependent and may or may not return sub-millisecond
310  // resolution.  THIS CALL IS GENERALLY MUCH MORE EXPENSIVE THAN Now() AND
311  // SHOULD ONLY BE USED WHEN IT IS REALLY NEEDED.
312  // This method never returns a null TimeTicks.
313  static TimeTicks HighResolutionNow();
314
315  // Returns true if the high-resolution clock is working on this system.
316  static bool IsHighResolutionClockWorking();
317
318  // Returns Linux kernel timestamp for generating profiler events. This method
319  // returns null TimeTicks if the kernel cannot provide the timestamps (e.g.,
320  // on non-Linux OS or if the kernel module for timestamps is not loaded).
321
322  static TimeTicks KernelTimestampNow();
323  static bool KernelTimestampAvailable();
324
325  // Returns true if this object has not been initialized.
326  bool IsNull() const { return ticks_ == 0; }
327
328  // Converts to/from internal values. The meaning of the "internal value" is
329  // completely up to the implementation, so it should be treated as opaque.
330  static TimeTicks FromInternalValue(int64_t value) {
331    return TimeTicks(value);
332  }
333  int64_t ToInternalValue() const {
334    return ticks_;
335  }
336
337  TimeTicks& operator=(const TimeTicks other) {
338    ticks_ = other.ticks_;
339    return *this;
340  }
341
342  // Compute the difference between two times.
343  TimeDelta operator-(const TimeTicks other) const {
344    return TimeDelta::FromMicroseconds(ticks_ - other.ticks_);
345  }
346
347  // Modify by some time delta.
348  TimeTicks& operator+=(const TimeDelta& delta) {
349    ticks_ += delta.InMicroseconds();
350    return *this;
351  }
352  TimeTicks& operator-=(const TimeDelta& delta) {
353    ticks_ -= delta.InMicroseconds();
354    return *this;
355  }
356
357  // Return a new TimeTicks modified by some delta.
358  TimeTicks operator+(const TimeDelta& delta) const {
359    return TimeTicks(ticks_ + delta.InMicroseconds());
360  }
361  TimeTicks operator-(const TimeDelta& delta) const {
362    return TimeTicks(ticks_ - delta.InMicroseconds());
363  }
364
365  // Comparison operators
366  bool operator==(const TimeTicks& other) const {
367    return ticks_ == other.ticks_;
368  }
369  bool operator!=(const TimeTicks& other) const {
370    return ticks_ != other.ticks_;
371  }
372  bool operator<(const TimeTicks& other) const {
373    return ticks_ < other.ticks_;
374  }
375  bool operator<=(const TimeTicks& other) const {
376    return ticks_ <= other.ticks_;
377  }
378  bool operator>(const TimeTicks& other) const {
379    return ticks_ > other.ticks_;
380  }
381  bool operator>=(const TimeTicks& other) const {
382    return ticks_ >= other.ticks_;
383  }
384
385 private:
386  // Please use Now() to create a new object. This is for internal use
387  // and testing. Ticks is in microseconds.
388  explicit TimeTicks(int64_t ticks) : ticks_(ticks) {}
389
390  // Tick count in microseconds.
391  int64_t ticks_;
392};
393
394inline TimeTicks operator+(const TimeDelta& delta, const TimeTicks& ticks) {
395  return ticks + delta;
396}
397
398} }  // namespace v8::base
399
400#endif  // V8_BASE_PLATFORM_TIME_H_
401