| // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "base/time/time.h" |
| |
| #include <stdint.h> |
| #include <sys/time.h> |
| #include <time.h> |
| #if defined(OS_ANDROID) && !defined(__LP64__) |
| #include <time64.h> |
| #endif |
| #include <unistd.h> |
| |
| #include <limits> |
| #include <ostream> |
| |
| #include "base/logging.h" |
| #include "build/build_config.h" |
| |
| #if defined(OS_ANDROID) |
| #include "base/os_compat_android.h" |
| #elif defined(OS_NACL) |
| #include "base/os_compat_nacl.h" |
| #endif |
| |
| #if !defined(OS_MACOSX) |
| #include "base/lazy_instance.h" |
| #include "base/synchronization/lock.h" |
| #endif |
| |
| namespace { |
| |
| #if !defined(OS_MACOSX) |
| // This prevents a crash on traversing the environment global and looking up |
| // the 'TZ' variable in libc. See: crbug.com/390567. |
| base::LazyInstance<base::Lock>::Leaky |
| g_sys_time_to_time_struct_lock = LAZY_INSTANCE_INITIALIZER; |
| |
| // Define a system-specific SysTime that wraps either to a time_t or |
| // a time64_t depending on the host system, and associated convertion. |
| // See crbug.com/162007 |
| #if defined(OS_ANDROID) && !defined(__LP64__) |
| typedef time64_t SysTime; |
| |
| SysTime SysTimeFromTimeStruct(struct tm* timestruct, bool is_local) { |
| base::AutoLock locked(g_sys_time_to_time_struct_lock.Get()); |
| if (is_local) |
| return mktime64(timestruct); |
| else |
| return timegm64(timestruct); |
| } |
| |
| void SysTimeToTimeStruct(SysTime t, struct tm* timestruct, bool is_local) { |
| base::AutoLock locked(g_sys_time_to_time_struct_lock.Get()); |
| if (is_local) |
| localtime64_r(&t, timestruct); |
| else |
| gmtime64_r(&t, timestruct); |
| } |
| |
| #else // OS_ANDROID && !__LP64__ |
| typedef time_t SysTime; |
| |
| SysTime SysTimeFromTimeStruct(struct tm* timestruct, bool is_local) { |
| base::AutoLock locked(g_sys_time_to_time_struct_lock.Get()); |
| if (is_local) |
| return mktime(timestruct); |
| else |
| return timegm(timestruct); |
| } |
| |
| void SysTimeToTimeStruct(SysTime t, struct tm* timestruct, bool is_local) { |
| base::AutoLock locked(g_sys_time_to_time_struct_lock.Get()); |
| if (is_local) |
| localtime_r(&t, timestruct); |
| else |
| gmtime_r(&t, timestruct); |
| } |
| #endif // OS_ANDROID |
| |
| int64_t ConvertTimespecToMicros(const struct timespec& ts) { |
| // On 32-bit systems, the calculation cannot overflow int64_t. |
| // 2**32 * 1000000 + 2**64 / 1000 < 2**63 |
| if (sizeof(ts.tv_sec) <= 4 && sizeof(ts.tv_nsec) <= 8) { |
| int64_t result = ts.tv_sec; |
| result *= base::Time::kMicrosecondsPerSecond; |
| result += (ts.tv_nsec / base::Time::kNanosecondsPerMicrosecond); |
| return result; |
| } else { |
| base::CheckedNumeric<int64_t> result(ts.tv_sec); |
| result *= base::Time::kMicrosecondsPerSecond; |
| result += (ts.tv_nsec / base::Time::kNanosecondsPerMicrosecond); |
| return result.ValueOrDie(); |
| } |
| } |
| |
| // Helper function to get results from clock_gettime() and convert to a |
| // microsecond timebase. Minimum requirement is MONOTONIC_CLOCK to be supported |
| // on the system. FreeBSD 6 has CLOCK_MONOTONIC but defines |
| // _POSIX_MONOTONIC_CLOCK to -1. |
| #if (defined(OS_POSIX) && \ |
| defined(_POSIX_MONOTONIC_CLOCK) && _POSIX_MONOTONIC_CLOCK >= 0) || \ |
| defined(OS_BSD) || defined(OS_ANDROID) |
| int64_t ClockNow(clockid_t clk_id) { |
| struct timespec ts; |
| if (clock_gettime(clk_id, &ts) != 0) { |
| NOTREACHED() << "clock_gettime(" << clk_id << ") failed."; |
| return 0; |
| } |
| return ConvertTimespecToMicros(ts); |
| } |
| #else // _POSIX_MONOTONIC_CLOCK |
| #error No usable tick clock function on this platform. |
| #endif // _POSIX_MONOTONIC_CLOCK |
| #endif // !defined(OS_MACOSX) |
| |
| } // namespace |
| |
| namespace base { |
| |
| // static |
| TimeDelta TimeDelta::FromTimeSpec(const timespec& ts) { |
| return TimeDelta(ts.tv_sec * Time::kMicrosecondsPerSecond + |
| ts.tv_nsec / Time::kNanosecondsPerMicrosecond); |
| } |
| |
| struct timespec TimeDelta::ToTimeSpec() const { |
| int64_t microseconds = InMicroseconds(); |
| time_t seconds = 0; |
| if (microseconds >= Time::kMicrosecondsPerSecond) { |
| seconds = InSeconds(); |
| microseconds -= seconds * Time::kMicrosecondsPerSecond; |
| } |
| struct timespec result = |
| {seconds, |
| static_cast<long>(microseconds * Time::kNanosecondsPerMicrosecond)}; |
| return result; |
| } |
| |
| #if !defined(OS_MACOSX) |
| // The Time routines in this file use standard POSIX routines, or almost- |
| // standard routines in the case of timegm. We need to use a Mach-specific |
| // function for TimeTicks::Now() on Mac OS X. |
| |
| // Time ----------------------------------------------------------------------- |
| |
| // Windows uses a Gregorian epoch of 1601. We need to match this internally |
| // so that our time representations match across all platforms. See bug 14734. |
| // irb(main):010:0> Time.at(0).getutc() |
| // => Thu Jan 01 00:00:00 UTC 1970 |
| // irb(main):011:0> Time.at(-11644473600).getutc() |
| // => Mon Jan 01 00:00:00 UTC 1601 |
| static const int64_t kWindowsEpochDeltaSeconds = INT64_C(11644473600); |
| |
| // static |
| const int64_t Time::kWindowsEpochDeltaMicroseconds = |
| kWindowsEpochDeltaSeconds * Time::kMicrosecondsPerSecond; |
| |
| // Some functions in time.cc use time_t directly, so we provide an offset |
| // to convert from time_t (Unix epoch) and internal (Windows epoch). |
| // static |
| const int64_t Time::kTimeTToMicrosecondsOffset = kWindowsEpochDeltaMicroseconds; |
| |
| // static |
| Time Time::Now() { |
| struct timeval tv; |
| struct timezone tz = { 0, 0 }; // UTC |
| if (gettimeofday(&tv, &tz) != 0) { |
| DCHECK(0) << "Could not determine time of day"; |
| PLOG(ERROR) << "Call to gettimeofday failed."; |
| // Return null instead of uninitialized |tv| value, which contains random |
| // garbage data. This may result in the crash seen in crbug.com/147570. |
| return Time(); |
| } |
| // Combine seconds and microseconds in a 64-bit field containing microseconds |
| // since the epoch. That's enough for nearly 600 centuries. Adjust from |
| // Unix (1970) to Windows (1601) epoch. |
| return Time((tv.tv_sec * kMicrosecondsPerSecond + tv.tv_usec) + |
| kWindowsEpochDeltaMicroseconds); |
| } |
| |
| // static |
| Time Time::NowFromSystemTime() { |
| // Just use Now() because Now() returns the system time. |
| return Now(); |
| } |
| |
| void Time::Explode(bool is_local, Exploded* exploded) const { |
| // Time stores times with microsecond resolution, but Exploded only carries |
| // millisecond resolution, so begin by being lossy. Adjust from Windows |
| // epoch (1601) to Unix epoch (1970); |
| int64_t microseconds = us_ - kWindowsEpochDeltaMicroseconds; |
| // The following values are all rounded towards -infinity. |
| int64_t milliseconds; // Milliseconds since epoch. |
| SysTime seconds; // Seconds since epoch. |
| int millisecond; // Exploded millisecond value (0-999). |
| if (microseconds >= 0) { |
| // Rounding towards -infinity <=> rounding towards 0, in this case. |
| milliseconds = microseconds / kMicrosecondsPerMillisecond; |
| seconds = milliseconds / kMillisecondsPerSecond; |
| millisecond = milliseconds % kMillisecondsPerSecond; |
| } else { |
| // Round these *down* (towards -infinity). |
| milliseconds = (microseconds - kMicrosecondsPerMillisecond + 1) / |
| kMicrosecondsPerMillisecond; |
| seconds = (milliseconds - kMillisecondsPerSecond + 1) / |
| kMillisecondsPerSecond; |
| // Make this nonnegative (and between 0 and 999 inclusive). |
| millisecond = milliseconds % kMillisecondsPerSecond; |
| if (millisecond < 0) |
| millisecond += kMillisecondsPerSecond; |
| } |
| |
| struct tm timestruct; |
| SysTimeToTimeStruct(seconds, ×truct, is_local); |
| |
| exploded->year = timestruct.tm_year + 1900; |
| exploded->month = timestruct.tm_mon + 1; |
| exploded->day_of_week = timestruct.tm_wday; |
| exploded->day_of_month = timestruct.tm_mday; |
| exploded->hour = timestruct.tm_hour; |
| exploded->minute = timestruct.tm_min; |
| exploded->second = timestruct.tm_sec; |
| exploded->millisecond = millisecond; |
| } |
| |
| // static |
| bool Time::FromExploded(bool is_local, const Exploded& exploded, Time* time) { |
| struct tm timestruct; |
| timestruct.tm_sec = exploded.second; |
| timestruct.tm_min = exploded.minute; |
| timestruct.tm_hour = exploded.hour; |
| timestruct.tm_mday = exploded.day_of_month; |
| timestruct.tm_mon = exploded.month - 1; |
| timestruct.tm_year = exploded.year - 1900; |
| timestruct.tm_wday = exploded.day_of_week; // mktime/timegm ignore this |
| timestruct.tm_yday = 0; // mktime/timegm ignore this |
| timestruct.tm_isdst = -1; // attempt to figure it out |
| #if !defined(OS_NACL) && !defined(OS_SOLARIS) |
| timestruct.tm_gmtoff = 0; // not a POSIX field, so mktime/timegm ignore |
| timestruct.tm_zone = NULL; // not a POSIX field, so mktime/timegm ignore |
| #endif |
| |
| SysTime seconds; |
| |
| // Certain exploded dates do not really exist due to daylight saving times, |
| // and this causes mktime() to return implementation-defined values when |
| // tm_isdst is set to -1. On Android, the function will return -1, while the |
| // C libraries of other platforms typically return a liberally-chosen value. |
| // Handling this requires the special code below. |
| |
| // SysTimeFromTimeStruct() modifies the input structure, save current value. |
| struct tm timestruct0 = timestruct; |
| |
| seconds = SysTimeFromTimeStruct(×truct, is_local); |
| if (seconds == -1) { |
| // Get the time values with tm_isdst == 0 and 1, then select the closest one |
| // to UTC 00:00:00 that isn't -1. |
| timestruct = timestruct0; |
| timestruct.tm_isdst = 0; |
| int64_t seconds_isdst0 = SysTimeFromTimeStruct(×truct, is_local); |
| |
| timestruct = timestruct0; |
| timestruct.tm_isdst = 1; |
| int64_t seconds_isdst1 = SysTimeFromTimeStruct(×truct, is_local); |
| |
| // seconds_isdst0 or seconds_isdst1 can be -1 for some timezones. |
| // E.g. "CLST" (Chile Summer Time) returns -1 for 'tm_isdt == 1'. |
| if (seconds_isdst0 < 0) |
| seconds = seconds_isdst1; |
| else if (seconds_isdst1 < 0) |
| seconds = seconds_isdst0; |
| else |
| seconds = std::min(seconds_isdst0, seconds_isdst1); |
| } |
| |
| // Handle overflow. Clamping the range to what mktime and timegm might |
| // return is the best that can be done here. It's not ideal, but it's better |
| // than failing here or ignoring the overflow case and treating each time |
| // overflow as one second prior to the epoch. |
| int64_t milliseconds = 0; |
| if (seconds == -1 && |
| (exploded.year < 1969 || exploded.year > 1970)) { |
| // If exploded.year is 1969 or 1970, take -1 as correct, with the |
| // time indicating 1 second prior to the epoch. (1970 is allowed to handle |
| // time zone and DST offsets.) Otherwise, return the most future or past |
| // time representable. Assumes the time_t epoch is 1970-01-01 00:00:00 UTC. |
| // |
| // The minimum and maximum representible times that mktime and timegm could |
| // return are used here instead of values outside that range to allow for |
| // proper round-tripping between exploded and counter-type time |
| // representations in the presence of possible truncation to time_t by |
| // division and use with other functions that accept time_t. |
| // |
| // When representing the most distant time in the future, add in an extra |
| // 999ms to avoid the time being less than any other possible value that |
| // this function can return. |
| |
| // On Android, SysTime is int64_t, special care must be taken to avoid |
| // overflows. |
| const int64_t min_seconds = (sizeof(SysTime) < sizeof(int64_t)) |
| ? std::numeric_limits<SysTime>::min() |
| : std::numeric_limits<int32_t>::min(); |
| const int64_t max_seconds = (sizeof(SysTime) < sizeof(int64_t)) |
| ? std::numeric_limits<SysTime>::max() |
| : std::numeric_limits<int32_t>::max(); |
| if (exploded.year < 1969) { |
| milliseconds = min_seconds * kMillisecondsPerSecond; |
| } else { |
| milliseconds = max_seconds * kMillisecondsPerSecond; |
| milliseconds += (kMillisecondsPerSecond - 1); |
| } |
| } else { |
| base::CheckedNumeric<int64_t> checked_millis = seconds; |
| checked_millis *= kMillisecondsPerSecond; |
| checked_millis += exploded.millisecond; |
| if (!checked_millis.IsValid()) { |
| *time = base::Time(0); |
| return false; |
| } |
| milliseconds = checked_millis.ValueOrDie(); |
| } |
| |
| // Adjust from Unix (1970) to Windows (1601) epoch avoiding overflows. |
| base::CheckedNumeric<int64_t> checked_microseconds_win_epoch = milliseconds; |
| checked_microseconds_win_epoch *= kMicrosecondsPerMillisecond; |
| checked_microseconds_win_epoch += kWindowsEpochDeltaMicroseconds; |
| if (!checked_microseconds_win_epoch.IsValid()) { |
| *time = base::Time(0); |
| return false; |
| } |
| base::Time converted_time(checked_microseconds_win_epoch.ValueOrDie()); |
| |
| // If |exploded.day_of_month| is set to 31 on a 28-30 day month, it will |
| // return the first day of the next month. Thus round-trip the time and |
| // compare the initial |exploded| with |utc_to_exploded| time. |
| base::Time::Exploded to_exploded; |
| if (!is_local) |
| converted_time.UTCExplode(&to_exploded); |
| else |
| converted_time.LocalExplode(&to_exploded); |
| |
| if (ExplodedMostlyEquals(to_exploded, exploded)) { |
| *time = converted_time; |
| return true; |
| } |
| |
| *time = Time(0); |
| return false; |
| } |
| |
| // TimeTicks ------------------------------------------------------------------ |
| // static |
| TimeTicks TimeTicks::Now() { |
| return TimeTicks(ClockNow(CLOCK_MONOTONIC)); |
| } |
| |
| // static |
| TimeTicks::Clock TimeTicks::GetClock() { |
| return Clock::LINUX_CLOCK_MONOTONIC; |
| } |
| |
| // static |
| bool TimeTicks::IsHighResolution() { |
| return true; |
| } |
| |
| // static |
| bool TimeTicks::IsConsistentAcrossProcesses() { |
| return true; |
| } |
| |
| // static |
| ThreadTicks ThreadTicks::Now() { |
| #if (defined(_POSIX_THREAD_CPUTIME) && (_POSIX_THREAD_CPUTIME >= 0)) || \ |
| defined(OS_ANDROID) |
| return ThreadTicks(ClockNow(CLOCK_THREAD_CPUTIME_ID)); |
| #else |
| NOTREACHED(); |
| return ThreadTicks(); |
| #endif |
| } |
| |
| #endif // !OS_MACOSX |
| |
| // static |
| Time Time::FromTimeVal(struct timeval t) { |
| DCHECK_LT(t.tv_usec, static_cast<int>(Time::kMicrosecondsPerSecond)); |
| DCHECK_GE(t.tv_usec, 0); |
| if (t.tv_usec == 0 && t.tv_sec == 0) |
| return Time(); |
| if (t.tv_usec == static_cast<suseconds_t>(Time::kMicrosecondsPerSecond) - 1 && |
| t.tv_sec == std::numeric_limits<time_t>::max()) |
| return Max(); |
| return Time((static_cast<int64_t>(t.tv_sec) * Time::kMicrosecondsPerSecond) + |
| t.tv_usec + kTimeTToMicrosecondsOffset); |
| } |
| |
| struct timeval Time::ToTimeVal() const { |
| struct timeval result; |
| if (is_null()) { |
| result.tv_sec = 0; |
| result.tv_usec = 0; |
| return result; |
| } |
| if (is_max()) { |
| result.tv_sec = std::numeric_limits<time_t>::max(); |
| result.tv_usec = static_cast<suseconds_t>(Time::kMicrosecondsPerSecond) - 1; |
| return result; |
| } |
| int64_t us = us_ - kTimeTToMicrosecondsOffset; |
| result.tv_sec = us / Time::kMicrosecondsPerSecond; |
| result.tv_usec = us % Time::kMicrosecondsPerSecond; |
| return result; |
| } |
| |
| } // namespace base |