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| 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 | |
| 3 // found in the LICENSE file. | |
| 4 | |
| 5 #include "base/time/time.h" | |
| 6 | |
| 7 #include <CoreFoundation/CFDate.h> | |
| 8 #include <CoreFoundation/CFTimeZone.h> | |
| 9 #include <mach/mach.h> | |
| 10 #include <mach/mach_time.h> | |
| 11 #include <stdint.h> | |
| 12 #include <sys/sysctl.h> | |
| 13 #include <sys/time.h> | |
| 14 #include <sys/types.h> | |
| 15 #include <time.h> | |
| 16 | |
| 17 #include "base/basictypes.h" | |
| 18 #include "base/logging.h" | |
| 19 #include "base/mac/mach_logging.h" | |
| 20 #include "base/mac/scoped_cftyperef.h" | |
| 21 #include "base/mac/scoped_mach_port.h" | |
| 22 #include "base/numerics/safe_conversions.h" | |
| 23 | |
| 24 namespace { | |
| 25 | |
| 26 int64_t ComputeCurrentTicks() { | |
| 27 #if defined(OS_IOS) | |
| 28 // On iOS mach_absolute_time stops while the device is sleeping. Instead use | |
| 29 // now - KERN_BOOTTIME to get a time difference that is not impacted by clock | |
| 30 // changes. KERN_BOOTTIME will be updated by the system whenever the system | |
| 31 // clock change. | |
| 32 struct timeval boottime; | |
| 33 int mib[2] = {CTL_KERN, KERN_BOOTTIME}; | |
| 34 size_t size = sizeof(boottime); | |
| 35 int kr = sysctl(mib, arraysize(mib), &boottime, &size, NULL, 0); | |
| 36 DCHECK_EQ(KERN_SUCCESS, kr); | |
| 37 base::TimeDelta time_difference = base::Time::Now() - | |
| 38 (base::Time::FromTimeT(boottime.tv_sec) + | |
| 39 base::TimeDelta::FromMicroseconds(boottime.tv_usec)); | |
| 40 return time_difference.InMicroseconds(); | |
| 41 #else | |
| 42 static mach_timebase_info_data_t timebase_info; | |
| 43 if (timebase_info.denom == 0) { | |
| 44 // Zero-initialization of statics guarantees that denom will be 0 before | |
| 45 // calling mach_timebase_info. mach_timebase_info will never set denom to | |
| 46 // 0 as that would be invalid, so the zero-check can be used to determine | |
| 47 // whether mach_timebase_info has already been called. This is | |
| 48 // recommended by Apple's QA1398. | |
| 49 kern_return_t kr = mach_timebase_info(&timebase_info); | |
| 50 MACH_DCHECK(kr == KERN_SUCCESS, kr) << "mach_timebase_info"; | |
| 51 } | |
| 52 | |
| 53 // mach_absolute_time is it when it comes to ticks on the Mac. Other calls | |
| 54 // with less precision (such as TickCount) just call through to | |
| 55 // mach_absolute_time. | |
| 56 | |
| 57 // timebase_info converts absolute time tick units into nanoseconds. Convert | |
| 58 // to microseconds up front to stave off overflows. | |
| 59 base::CheckedNumeric<uint64_t> result( | |
| 60 mach_absolute_time() / base::Time::kNanosecondsPerMicrosecond); | |
| 61 result *= timebase_info.numer; | |
| 62 result /= timebase_info.denom; | |
| 63 | |
| 64 // Don't bother with the rollover handling that the Windows version does. | |
| 65 // With numer and denom = 1 (the expected case), the 64-bit absolute time | |
| 66 // reported in nanoseconds is enough to last nearly 585 years. | |
| 67 return base::checked_cast<int64_t>(result.ValueOrDie()); | |
| 68 #endif // defined(OS_IOS) | |
| 69 } | |
| 70 | |
| 71 int64_t ComputeThreadTicks() { | |
| 72 base::mac::ScopedMachSendRight thread(mach_thread_self()); | |
| 73 mach_msg_type_number_t thread_info_count = THREAD_BASIC_INFO_COUNT; | |
| 74 thread_basic_info_data_t thread_info_data; | |
| 75 | |
| 76 if (thread.get() == MACH_PORT_NULL) { | |
| 77 DLOG(ERROR) << "Failed to get mach_thread_self()"; | |
| 78 return 0; | |
| 79 } | |
| 80 | |
| 81 kern_return_t kr = thread_info( | |
| 82 thread, | |
| 83 THREAD_BASIC_INFO, | |
| 84 reinterpret_cast<thread_info_t>(&thread_info_data), | |
| 85 &thread_info_count); | |
| 86 MACH_DCHECK(kr == KERN_SUCCESS, kr) << "thread_info"; | |
| 87 | |
| 88 base::CheckedNumeric<int64_t> absolute_micros( | |
| 89 thread_info_data.user_time.seconds); | |
| 90 absolute_micros *= base::Time::kMicrosecondsPerSecond; | |
| 91 absolute_micros += thread_info_data.user_time.microseconds; | |
| 92 return absolute_micros.ValueOrDie(); | |
| 93 } | |
| 94 | |
| 95 } // namespace | |
| 96 | |
| 97 namespace base { | |
| 98 | |
| 99 // The Time routines in this file use Mach and CoreFoundation APIs, since the | |
| 100 // POSIX definition of time_t in Mac OS X wraps around after 2038--and | |
| 101 // there are already cookie expiration dates, etc., past that time out in | |
| 102 // the field. Using CFDate prevents that problem, and using mach_absolute_time | |
| 103 // for TimeTicks gives us nice high-resolution interval timing. | |
| 104 | |
| 105 // Time ----------------------------------------------------------------------- | |
| 106 | |
| 107 // Core Foundation uses a double second count since 2001-01-01 00:00:00 UTC. | |
| 108 // The UNIX epoch is 1970-01-01 00:00:00 UTC. | |
| 109 // Windows uses a Gregorian epoch of 1601. We need to match this internally | |
| 110 // so that our time representations match across all platforms. See bug 14734. | |
| 111 // irb(main):010:0> Time.at(0).getutc() | |
| 112 // => Thu Jan 01 00:00:00 UTC 1970 | |
| 113 // irb(main):011:0> Time.at(-11644473600).getutc() | |
| 114 // => Mon Jan 01 00:00:00 UTC 1601 | |
| 115 static const int64 kWindowsEpochDeltaSeconds = INT64_C(11644473600); | |
| 116 | |
| 117 // static | |
| 118 const int64 Time::kWindowsEpochDeltaMicroseconds = | |
| 119 kWindowsEpochDeltaSeconds * Time::kMicrosecondsPerSecond; | |
| 120 | |
| 121 // Some functions in time.cc use time_t directly, so we provide an offset | |
| 122 // to convert from time_t (Unix epoch) and internal (Windows epoch). | |
| 123 // static | |
| 124 const int64 Time::kTimeTToMicrosecondsOffset = kWindowsEpochDeltaMicroseconds; | |
| 125 | |
| 126 // static | |
| 127 Time Time::Now() { | |
| 128 return FromCFAbsoluteTime(CFAbsoluteTimeGetCurrent()); | |
| 129 } | |
| 130 | |
| 131 // static | |
| 132 Time Time::FromCFAbsoluteTime(CFAbsoluteTime t) { | |
| 133 COMPILE_ASSERT(std::numeric_limits<CFAbsoluteTime>::has_infinity, | |
| 134 numeric_limits_infinity_is_undefined_when_not_has_infinity); | |
| 135 if (t == 0) | |
| 136 return Time(); // Consider 0 as a null Time. | |
| 137 if (t == std::numeric_limits<CFAbsoluteTime>::infinity()) | |
| 138 return Max(); | |
| 139 return Time(static_cast<int64>( | |
| 140 (t + kCFAbsoluteTimeIntervalSince1970) * kMicrosecondsPerSecond) + | |
| 141 kWindowsEpochDeltaMicroseconds); | |
| 142 } | |
| 143 | |
| 144 CFAbsoluteTime Time::ToCFAbsoluteTime() const { | |
| 145 COMPILE_ASSERT(std::numeric_limits<CFAbsoluteTime>::has_infinity, | |
| 146 numeric_limits_infinity_is_undefined_when_not_has_infinity); | |
| 147 if (is_null()) | |
| 148 return 0; // Consider 0 as a null Time. | |
| 149 if (is_max()) | |
| 150 return std::numeric_limits<CFAbsoluteTime>::infinity(); | |
| 151 return (static_cast<CFAbsoluteTime>(us_ - kWindowsEpochDeltaMicroseconds) / | |
| 152 kMicrosecondsPerSecond) - kCFAbsoluteTimeIntervalSince1970; | |
| 153 } | |
| 154 | |
| 155 // static | |
| 156 Time Time::NowFromSystemTime() { | |
| 157 // Just use Now() because Now() returns the system time. | |
| 158 return Now(); | |
| 159 } | |
| 160 | |
| 161 // static | |
| 162 Time Time::FromExploded(bool is_local, const Exploded& exploded) { | |
| 163 CFGregorianDate date; | |
| 164 date.second = exploded.second + | |
| 165 exploded.millisecond / static_cast<double>(kMillisecondsPerSecond); | |
| 166 date.minute = exploded.minute; | |
| 167 date.hour = exploded.hour; | |
| 168 date.day = exploded.day_of_month; | |
| 169 date.month = exploded.month; | |
| 170 date.year = exploded.year; | |
| 171 | |
| 172 base::ScopedCFTypeRef<CFTimeZoneRef> time_zone( | |
| 173 is_local ? CFTimeZoneCopySystem() : NULL); | |
| 174 CFAbsoluteTime seconds = CFGregorianDateGetAbsoluteTime(date, time_zone) + | |
| 175 kCFAbsoluteTimeIntervalSince1970; | |
| 176 return Time(static_cast<int64>(seconds * kMicrosecondsPerSecond) + | |
| 177 kWindowsEpochDeltaMicroseconds); | |
| 178 } | |
| 179 | |
| 180 void Time::Explode(bool is_local, Exploded* exploded) const { | |
| 181 // Avoid rounding issues, by only putting the integral number of seconds | |
| 182 // (rounded towards -infinity) into a |CFAbsoluteTime| (which is a |double|). | |
| 183 int64 microsecond = us_ % kMicrosecondsPerSecond; | |
| 184 if (microsecond < 0) | |
| 185 microsecond += kMicrosecondsPerSecond; | |
| 186 CFAbsoluteTime seconds = ((us_ - microsecond) / kMicrosecondsPerSecond) - | |
| 187 kWindowsEpochDeltaSeconds - | |
| 188 kCFAbsoluteTimeIntervalSince1970; | |
| 189 | |
| 190 base::ScopedCFTypeRef<CFTimeZoneRef> time_zone( | |
| 191 is_local ? CFTimeZoneCopySystem() : NULL); | |
| 192 CFGregorianDate date = CFAbsoluteTimeGetGregorianDate(seconds, time_zone); | |
| 193 // 1 = Monday, ..., 7 = Sunday. | |
| 194 int cf_day_of_week = CFAbsoluteTimeGetDayOfWeek(seconds, time_zone); | |
| 195 | |
| 196 exploded->year = date.year; | |
| 197 exploded->month = date.month; | |
| 198 exploded->day_of_week = cf_day_of_week % 7; | |
| 199 exploded->day_of_month = date.day; | |
| 200 exploded->hour = date.hour; | |
| 201 exploded->minute = date.minute; | |
| 202 // Make sure seconds are rounded down towards -infinity. | |
| 203 exploded->second = floor(date.second); | |
| 204 // Calculate milliseconds ourselves, since we rounded the |seconds|, making | |
| 205 // sure to round towards -infinity. | |
| 206 exploded->millisecond = | |
| 207 (microsecond >= 0) ? microsecond / kMicrosecondsPerMillisecond : | |
| 208 (microsecond - kMicrosecondsPerMillisecond + 1) / | |
| 209 kMicrosecondsPerMillisecond; | |
| 210 } | |
| 211 | |
| 212 // TimeTicks ------------------------------------------------------------------ | |
| 213 | |
| 214 // static | |
| 215 TimeTicks TimeTicks::Now() { | |
| 216 return TimeTicks(ComputeCurrentTicks()); | |
| 217 } | |
| 218 | |
| 219 // static | |
| 220 bool TimeTicks::IsHighResolution() { | |
| 221 return true; | |
| 222 } | |
| 223 | |
| 224 // static | |
| 225 ThreadTicks ThreadTicks::Now() { | |
| 226 return ThreadTicks(ComputeThreadTicks()); | |
| 227 } | |
| 228 | |
| 229 // static | |
| 230 TraceTicks TraceTicks::Now() { | |
| 231 return TraceTicks(ComputeCurrentTicks()); | |
| 232 } | |
| 233 | |
| 234 } // namespace base | |
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