OLD | NEW |
---|---|
1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. | 1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 // Time represents an absolute point in coordinated universal time (UTC), | 5 // Time represents an absolute point in coordinated universal time (UTC), |
6 // internally represented as microseconds (s/1,000,000) since the Windows epoch | 6 // internally represented as microseconds (s/1,000,000) since the Windows epoch |
7 // (1601-01-01 00:00:00 UTC) (See http://crbug.com/14734). System-dependent | 7 // (1601-01-01 00:00:00 UTC) (See http://crbug.com/14734). System-dependent |
8 // clock interface routines are defined in time_PLATFORM.cc. | 8 // clock interface routines are defined in time_PLATFORM.cc. |
9 // | 9 // |
10 // TimeDelta represents a duration of time, internally represented in | 10 // TimeDelta represents a duration of time, internally represented in |
(...skipping 11 matching lines...) Expand all Loading... | |
22 // | 22 // |
23 // Definitions of operator<< are provided to make these types work with | 23 // Definitions of operator<< are provided to make these types work with |
24 // DCHECK_EQ() and other log macros. For human-readable formatting, see | 24 // DCHECK_EQ() and other log macros. For human-readable formatting, see |
25 // "base/i18n/time_formatting.h". | 25 // "base/i18n/time_formatting.h". |
26 | 26 |
27 #ifndef BASE_TIME_TIME_H_ | 27 #ifndef BASE_TIME_TIME_H_ |
28 #define BASE_TIME_TIME_H_ | 28 #define BASE_TIME_TIME_H_ |
29 | 29 |
30 #include <time.h> | 30 #include <time.h> |
31 | 31 |
32 #include <cstdlib> | |
32 #include <iosfwd> | 33 #include <iosfwd> |
33 | 34 |
34 #include "base/base_export.h" | 35 #include "base/base_export.h" |
35 #include "base/basictypes.h" | 36 #include "base/basictypes.h" |
36 #include "build/build_config.h" | 37 #include "build/build_config.h" |
37 | 38 |
38 #if defined(OS_MACOSX) | 39 #if defined(OS_MACOSX) |
39 #include <CoreFoundation/CoreFoundation.h> | 40 #include <CoreFoundation/CoreFoundation.h> |
40 // Avoid Mac system header macro leak. | 41 // Avoid Mac system header macro leak. |
41 #undef TYPE_BOOL | 42 #undef TYPE_BOOL |
(...skipping 51 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... | |
93 static TimeDelta Max(); | 94 static TimeDelta Max(); |
94 | 95 |
95 // Returns the internal numeric value of the TimeDelta object. Please don't | 96 // Returns the internal numeric value of the TimeDelta object. Please don't |
96 // use this and do arithmetic on it, as it is more error prone than using the | 97 // use this and do arithmetic on it, as it is more error prone than using the |
97 // provided operators. | 98 // provided operators. |
98 // For serializing, use FromInternalValue to reconstitute. | 99 // For serializing, use FromInternalValue to reconstitute. |
99 int64 ToInternalValue() const { | 100 int64 ToInternalValue() const { |
100 return delta_; | 101 return delta_; |
101 } | 102 } |
102 | 103 |
104 // Returns true if this TimeDelta is negative. | |
105 bool is_negative() const { | |
brianderson
2015/01/07 00:53:43
This is not used and appears unrelated. If the int
miu
2015/01/07 05:22:45
Ah. Yes, it was used in an earlier iteration of t
| |
106 return delta_ < 0; | |
107 } | |
108 | |
109 // Returns the magnitude (absolute value) of this TimeDelta. | |
110 TimeDelta magnitude() const { | |
brianderson
2015/01/07 00:53:43
This is only used for testing. Do you plan to use
miu
2015/01/07 05:22:45
Yes. I've personally written a lot of code in src
| |
111 return TimeDelta(std::abs(delta_)); | |
112 } | |
113 | |
103 // Returns true if the time delta is the maximum time delta. | 114 // Returns true if the time delta is the maximum time delta. |
104 bool is_max() const { | 115 bool is_max() const { |
105 return delta_ == std::numeric_limits<int64>::max(); | 116 return delta_ == std::numeric_limits<int64>::max(); |
106 } | 117 } |
107 | 118 |
108 #if defined(OS_POSIX) | 119 #if defined(OS_POSIX) |
109 struct timespec ToTimeSpec() const; | 120 struct timespec ToTimeSpec() const; |
110 #endif | 121 #endif |
111 | 122 |
112 // Returns the time delta in some unit. The F versions return a floating | 123 // Returns the time delta in some unit. The F versions return a floating |
(...skipping 468 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... | |
581 #if defined(OS_LINUX) | 592 #if defined(OS_LINUX) |
582 // Force definition of the system trace clock; it is a chromeos-only api | 593 // Force definition of the system trace clock; it is a chromeos-only api |
583 // at the moment and surfacing it in the right place requires mucking | 594 // at the moment and surfacing it in the right place requires mucking |
584 // with glibc et al. | 595 // with glibc et al. |
585 static const clockid_t kClockSystemTrace = 11; | 596 static const clockid_t kClockSystemTrace = 11; |
586 #endif | 597 #endif |
587 | 598 |
588 TimeTicks() : ticks_(0) { | 599 TimeTicks() : ticks_(0) { |
589 } | 600 } |
590 | 601 |
591 // Platform-dependent tick count representing "right now." | 602 // Platform-dependent tick count representing "right now." When |
592 // The resolution of this clock is ~1-15ms. Resolution varies depending | 603 // IsHighResolution() returns false, the resolution of the clock could be |
593 // on hardware/operating system configuration. | 604 // as coarse as ~15.6ms. Otherwise, the resolution should be no worse than one |
605 // microsecond. | |
594 static TimeTicks Now(); | 606 static TimeTicks Now(); |
595 | 607 |
596 // Returns a platform-dependent high-resolution tick count. Implementation | 608 // DEPRECATED |
597 // is hardware dependent and may or may not return sub-millisecond | 609 // TODO(miu): Remove this function, and all callpoints should call Now(). |
598 // resolution. THIS CALL IS GENERALLY MUCH MORE EXPENSIVE THAN Now() AND | 610 static TimeTicks HighResNow() { return TimeTicks::Now(); } |
599 // SHOULD ONLY BE USED WHEN IT IS REALLY NEEDED. | |
600 static TimeTicks HighResNow(); | |
601 | 611 |
602 static bool IsHighResNowFastAndReliable(); | 612 // Returns true if the high resolution clock is working on this system and |
613 // Now() will return high resolution values. Note that, on systems where the | |
614 // high resolution clock works but is deemed inefficient, the low resolution | |
615 // clock will be used instead. | |
616 static bool IsHighResolution(); | |
617 | |
618 // DEPRECATED | |
619 // TODO(miu): Remove this function, and all callpoints should call | |
620 // IsHighResolution(). | |
621 static bool IsHighResNowFastAndReliable() { return IsHighResolution(); } | |
603 | 622 |
604 // Returns true if ThreadNow() is supported on this system. | 623 // Returns true if ThreadNow() is supported on this system. |
605 static bool IsThreadNowSupported() { | 624 static bool IsThreadNowSupported() { |
606 #if (defined(_POSIX_THREAD_CPUTIME) && (_POSIX_THREAD_CPUTIME >= 0)) || \ | 625 #if (defined(_POSIX_THREAD_CPUTIME) && (_POSIX_THREAD_CPUTIME >= 0)) || \ |
607 (defined(OS_MACOSX) && !defined(OS_IOS)) || defined(OS_ANDROID) | 626 (defined(OS_MACOSX) && !defined(OS_IOS)) || defined(OS_ANDROID) |
608 return true; | 627 return true; |
609 #else | 628 #else |
610 return false; | 629 return false; |
611 #endif | 630 #endif |
612 } | 631 } |
613 | 632 |
614 // Returns thread-specific CPU-time on systems that support this feature. | 633 // Returns thread-specific CPU-time on systems that support this feature. |
615 // Needs to be guarded with a call to IsThreadNowSupported(). Use this timer | 634 // Needs to be guarded with a call to IsThreadNowSupported(). Use this timer |
616 // to (approximately) measure how much time the calling thread spent doing | 635 // to (approximately) measure how much time the calling thread spent doing |
617 // actual work vs. being de-scheduled. May return bogus results if the thread | 636 // actual work vs. being de-scheduled. May return bogus results if the thread |
618 // migrates to another CPU between two calls. | 637 // migrates to another CPU between two calls. |
638 // | |
639 // WARNING: The returned value might NOT have the same origin as Now(). Do not | |
640 // perform math with TimeTicks values returned by Now() and expect meaningful | |
641 // results. | |
642 // TODO(miu): Since the timeline of these values is different, the values | |
643 // should be of a different type. | |
619 static TimeTicks ThreadNow(); | 644 static TimeTicks ThreadNow(); |
620 | 645 |
621 // Returns the current system trace time or, if none is defined, the current | 646 // Returns the current system trace time or, if not available on this |
622 // high-res time (i.e. HighResNow()). On systems where a global trace clock | 647 // platform, a high-resolution time value; or a low-resolution time value if |
623 // is defined, timestamping TraceEvents's with this value guarantees | 648 // neither are avalable. On systems where a global trace clock is defined, |
624 // synchronization between events collected inside chrome and events | 649 // timestamping TraceEvents's with this value guarantees synchronization |
625 // collected outside (e.g. kernel, X server). | 650 // between events collected inside chrome and events collected outside |
651 // (e.g. kernel, X server). | |
652 // | |
653 // WARNING: The returned value might NOT have the same origin as Now(). Do not | |
654 // perform math with TimeTicks values returned by Now() and expect meaningful | |
655 // results. | |
656 // TODO(miu): Since the timeline of these values is different, the values | |
657 // should be of a different type. | |
626 static TimeTicks NowFromSystemTraceTime(); | 658 static TimeTicks NowFromSystemTraceTime(); |
627 | 659 |
628 #if defined(OS_WIN) | 660 #if defined(OS_WIN) |
629 // Get the absolute value of QPC time drift. For testing. | 661 // Translates an absolute QPC timestamp into a TimeTicks value. The returned |
630 static int64 GetQPCDriftMicroseconds(); | 662 // value has the same origin as Now(). Do NOT attempt to use this if |
631 | 663 // IsHighResolution() returns false. |
632 static TimeTicks FromQPCValue(LONGLONG qpc_value); | 664 static TimeTicks FromQPCValue(LONGLONG qpc_value); |
633 | |
634 // Returns true if the high resolution clock is working on this system. | |
635 // This is only for testing. | |
636 static bool IsHighResClockWorking(); | |
637 #endif | 665 #endif |
638 | 666 |
639 // Returns true if this object has not been initialized. | 667 // Returns true if this object has not been initialized. |
640 bool is_null() const { | 668 bool is_null() const { |
641 return ticks_ == 0; | 669 return ticks_ == 0; |
642 } | 670 } |
643 | 671 |
644 // Converts an integer value representing TimeTicks to a class. This is used | 672 // Converts an integer value representing TimeTicks to a class. This is used |
645 // when deserializing a |TimeTicks| structure, using a value known to be | 673 // when deserializing a |TimeTicks| structure, using a value known to be |
646 // compatible. It is not provided as a constructor because the integer type | 674 // compatible. It is not provided as a constructor because the integer type |
(...skipping 84 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... | |
731 inline TimeTicks TimeDelta::operator+(TimeTicks t) const { | 759 inline TimeTicks TimeDelta::operator+(TimeTicks t) const { |
732 return TimeTicks(t.ticks_ + delta_); | 760 return TimeTicks(t.ticks_ + delta_); |
733 } | 761 } |
734 | 762 |
735 // For logging use only. | 763 // For logging use only. |
736 BASE_EXPORT std::ostream& operator<<(std::ostream& os, TimeTicks time_ticks); | 764 BASE_EXPORT std::ostream& operator<<(std::ostream& os, TimeTicks time_ticks); |
737 | 765 |
738 } // namespace base | 766 } // namespace base |
739 | 767 |
740 #endif // BASE_TIME_TIME_H_ | 768 #endif // BASE_TIME_TIME_H_ |
OLD | NEW |