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// 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 "base/logging.h"
#include "base/numerics/safe_math.h"
#include "base/time/time_override.h"
#include "build/build_config.h"
// Ensure the Fuchsia and Mac builds do not include this module. Instead,
// non-POSIX implementation is used for sampling the system clocks.
#if defined(OS_FUCHSIA) || defined(OS_MACOSX)
#error "This implementation is for POSIX platforms other than Fuchsia or Mac."
#endif
namespace {
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;
}
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;
CHECK(clock_gettime(clk_id, &ts) == 0);
return ConvertTimespecToMicros(ts);
}
#else // _POSIX_MONOTONIC_CLOCK
#error No usable tick clock function on this platform.
#endif // _POSIX_MONOTONIC_CLOCK
} // namespace
namespace base {
// Time -----------------------------------------------------------------------
namespace subtle {
Time TimeNowIgnoringOverride() {
struct timeval tv;
struct timezone tz = {0, 0}; // UTC
CHECK(gettimeofday(&tv, &tz) == 0);
// 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() + TimeDelta::FromMicroseconds(
(tv.tv_sec * Time::kMicrosecondsPerSecond + tv.tv_usec) +
Time::kTimeTToMicrosecondsOffset);
}
Time TimeNowFromSystemTimeIgnoringOverride() {
// Just use TimeNowIgnoringOverride() because it returns the system time.
return TimeNowIgnoringOverride();
}
} // namespace subtle
// TimeTicks ------------------------------------------------------------------
namespace subtle {
TimeTicks TimeTicksNowIgnoringOverride() {
return TimeTicks() + TimeDelta::FromMicroseconds(ClockNow(CLOCK_MONOTONIC));
}
} // namespace subtle
// static
TimeTicks::Clock TimeTicks::GetClock() {
return Clock::LINUX_CLOCK_MONOTONIC;
}
// static
bool TimeTicks::IsHighResolution() {
return true;
}
// static
bool TimeTicks::IsConsistentAcrossProcesses() {
return true;
}
// ThreadTicks ----------------------------------------------------------------
namespace subtle {
ThreadTicks ThreadTicksNowIgnoringOverride() {
#if (defined(_POSIX_THREAD_CPUTIME) && (_POSIX_THREAD_CPUTIME >= 0)) || \
defined(OS_ANDROID)
return ThreadTicks() +
TimeDelta::FromMicroseconds(ClockNow(CLOCK_THREAD_CPUTIME_ID));
#else
NOTREACHED();
return ThreadTicks();
#endif
}
} // namespace subtle
} // namespace base
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