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Diffstat (limited to 'ipc/chromium/src/base/time_mac.cc')
-rw-r--r-- | ipc/chromium/src/base/time_mac.cc | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/ipc/chromium/src/base/time_mac.cc b/ipc/chromium/src/base/time_mac.cc new file mode 100644 index 000000000..a5a9a2a6e --- /dev/null +++ b/ipc/chromium/src/base/time_mac.cc @@ -0,0 +1,127 @@ +/* -*- 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) 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" + +#include <CoreFoundation/CFDate.h> +#include <CoreFoundation/CFTimeZone.h> +#include <mach/mach_time.h> +#include <sys/time.h> +#include <time.h> + +#include "base/basictypes.h" +#include "base/logging.h" +#include "base/scoped_cftyperef.h" + +namespace base { + +// The Time routines in this file use Mach and CoreFoundation APIs, since the +// POSIX definition of time_t in Mac OS X wraps around after 2038--and +// there are already cookie expiration dates, etc., past that time out in +// the field. Using CFDate prevents that problem, and using mach_absolute_time +// for TimeTicks gives us nice high-resolution interval timing. + +// Time ----------------------------------------------------------------------- + +// The internal representation of Time uses a 64-bit microsecond count +// from 1970-01-01 00:00:00 UTC. Core Foundation uses a double second count +// since 2001-01-01 00:00:00 UTC. + +// 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() { + CFAbsoluteTime now = + CFAbsoluteTimeGetCurrent() + kCFAbsoluteTimeIntervalSince1970; + return Time(static_cast<int64_t>(now * kMicrosecondsPerSecond)); +} + +// 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) { + CFGregorianDate date; + date.second = exploded.second + + exploded.millisecond / static_cast<double>(kMillisecondsPerSecond); + date.minute = exploded.minute; + date.hour = exploded.hour; + date.day = exploded.day_of_month; + date.month = exploded.month; + date.year = exploded.year; + + scoped_cftyperef<CFTimeZoneRef> + time_zone(is_local ? CFTimeZoneCopySystem() : NULL); + CFAbsoluteTime seconds = CFGregorianDateGetAbsoluteTime(date, time_zone) + + kCFAbsoluteTimeIntervalSince1970; + return Time(static_cast<int64_t>(seconds * kMicrosecondsPerSecond)); +} + +void Time::Explode(bool is_local, Exploded* exploded) const { + CFAbsoluteTime seconds = + (static_cast<double>(us_) / kMicrosecondsPerSecond) - + kCFAbsoluteTimeIntervalSince1970; + + scoped_cftyperef<CFTimeZoneRef> + time_zone(is_local ? CFTimeZoneCopySystem() : NULL); + CFGregorianDate date = CFAbsoluteTimeGetGregorianDate(seconds, time_zone); + + exploded->year = date.year; + exploded->month = date.month; + exploded->day_of_month = date.day; + exploded->hour = date.hour; + exploded->minute = date.minute; + exploded->second = date.second; + exploded->millisecond = + static_cast<int>(date.second * kMillisecondsPerSecond) % + kMillisecondsPerSecond; +} + +// TimeTicks ------------------------------------------------------------------ + +// static +TimeTicks TimeTicks::Now() { + uint64_t absolute_micro; + + 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. + + return TimeTicks(absolute_micro); +} + +// static +TimeTicks TimeTicks::HighResNow() { + return Now(); +} + +} // namespace base |