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Diffstat (limited to 'ipc/chromium/src/base/time_posix.cc')
| -rw-r--r-- | ipc/chromium/src/base/time_posix.cc | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/ipc/chromium/src/base/time_posix.cc b/ipc/chromium/src/base/time_posix.cc new file mode 100644 index 000000000..2eb76a989 --- /dev/null +++ b/ipc/chromium/src/base/time_posix.cc @@ -0,0 +1,203 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +// Copyright (c) 2006-2008 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.h" + +#ifdef OS_MACOSX +#include <mach/mach_time.h> +#endif +#include <sys/time.h> +#if defined(ANDROID) && !defined(__LP64__) +#include <time64.h> +#else +#include <time.h> +#endif +#if defined(ANDROID) || defined(OS_POSIX) +#include <unistd.h> +#endif + +#include <limits> + +#include "base/basictypes.h" +#include "base/logging.h" + +namespace base { + +// 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 ----------------------------------------------------------------------- + +// Some functions in time.cc use time_t directly, so we provide a zero offset +// for them. The epoch is 1970-01-01 00:00:00 UTC. +// static +const int64_t Time::kTimeTToMicrosecondsOffset = GG_INT64_C(0); + +// 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"; + } + // Combine seconds and microseconds in a 64-bit field containing microseconds + // since the epoch. That's enough for nearly 600 centuries. + return Time(tv.tv_sec * kMicrosecondsPerSecond + tv.tv_usec); +} + +// static +Time Time::NowFromSystemTime() { + // Just use Now() because Now() returns the system time. + return Now(); +} + +// static +Time Time::FromExploded(bool is_local, const Exploded& exploded) { + 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 + timestruct.tm_gmtoff = 0; // not a POSIX field, so mktime/timegm ignore + timestruct.tm_zone = NULL; // not a POSIX field, so mktime/timegm ignore + + time_t seconds; +#ifdef ANDROID + seconds = mktime(×truct); +#else + if (is_local) + seconds = mktime(×truct); + else + seconds = timegm(×truct); +#endif + + int64_t milliseconds; + // 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. + 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. + + // Take care to avoid overflows when time_t is int64_t. + if (exploded.year < 1969) { + int64_t min_seconds = (sizeof(time_t) < sizeof(int64_t)) + ? std::numeric_limits<time_t>::min() + : std::numeric_limits<int32_t>::min(); + milliseconds = min_seconds * kMillisecondsPerSecond; + } else { + int64_t max_seconds = (sizeof(time_t) < sizeof(int64_t)) + ? std::numeric_limits<time_t>::max() + : std::numeric_limits<int32_t>::max(); + milliseconds = max_seconds * kMillisecondsPerSecond; + milliseconds += kMillisecondsPerSecond - 1; + } + } else { + milliseconds = seconds * kMillisecondsPerSecond + exploded.millisecond; + } + + return Time(milliseconds * kMicrosecondsPerMillisecond); +} + +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. + int64_t milliseconds = us_ / kMicrosecondsPerMillisecond; + time_t seconds = milliseconds / kMillisecondsPerSecond; + + struct tm timestruct; + if (is_local) + localtime_r(&seconds, ×truct); + else + gmtime_r(&seconds, ×truct); + + 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 = milliseconds % kMillisecondsPerSecond; +} + +// TimeTicks ------------------------------------------------------------------ + +// static +TimeTicks TimeTicks::Now() { + uint64_t absolute_micro; + +#if defined(OS_MACOSX) + static mach_timebase_info_data_t timebase_info; + if (timebase_info.denom == 0) { + // Zero-initialization of statics guarantees that denom will be 0 before + // calling mach_timebase_info. mach_timebase_info will never set denom to + // 0 as that would be invalid, so the zero-check can be used to determine + // whether mach_timebase_info has already been called. This is + // recommended by Apple's QA1398. + kern_return_t kr = mach_timebase_info(&timebase_info); + DCHECK(kr == KERN_SUCCESS); + } + + // mach_absolute_time is it when it comes to ticks on the Mac. Other calls + // with less precision (such as TickCount) just call through to + // mach_absolute_time. + + // timebase_info converts absolute time tick units into nanoseconds. Convert + // to microseconds up front to stave off overflows. + absolute_micro = mach_absolute_time() / Time::kNanosecondsPerMicrosecond * + timebase_info.numer / timebase_info.denom; + + // Don't bother with the rollover handling that the Windows version does. + // With numer and denom = 1 (the expected case), the 64-bit absolute time + // reported in nanoseconds is enough to last nearly 585 years. + +#elif defined(OS_OPENBSD) || defined(OS_POSIX) && \ + defined(_POSIX_MONOTONIC_CLOCK) && _POSIX_MONOTONIC_CLOCK >= 0 + + struct timespec ts; + if (clock_gettime(CLOCK_MONOTONIC, &ts) != 0) { + NOTREACHED() << "clock_gettime(CLOCK_MONOTONIC) failed."; + return TimeTicks(); + } + + absolute_micro = + (static_cast<int64_t>(ts.tv_sec) * Time::kMicrosecondsPerSecond) + + (static_cast<int64_t>(ts.tv_nsec) / Time::kNanosecondsPerMicrosecond); + +#else // _POSIX_MONOTONIC_CLOCK +#error No usable tick clock function on this platform. +#endif // _POSIX_MONOTONIC_CLOCK + + return TimeTicks(absolute_micro); +} + +// static +TimeTicks TimeTicks::HighResNow() { + return Now(); +} + +} // namespace base |