| Index: third_party/libc++/src/chrono.cpp
|
| ===================================================================
|
| --- third_party/libc++/src/chrono.cpp (revision 0)
|
| +++ third_party/libc++/src/chrono.cpp (revision 0)
|
| @@ -0,0 +1,132 @@
|
| +//===------------------------- chrono.cpp ---------------------------------===//
|
| +//
|
| +// The LLVM Compiler Infrastructure
|
| +//
|
| +// This file is dual licensed under the MIT and the University of Illinois Open
|
| +// Source Licenses. See LICENSE.TXT for details.
|
| +//
|
| +//===----------------------------------------------------------------------===//
|
| +
|
| +#include "chrono"
|
| +#include <sys/time.h> //for gettimeofday and timeval
|
| +#ifdef __APPLE__
|
| +#include <mach/mach_time.h> // mach_absolute_time, mach_timebase_info_data_t
|
| +#else /* !__APPLE__ */
|
| +#include <cerrno> // errno
|
| +#include <system_error> // __throw_system_error
|
| +#include <time.h> // clock_gettime, CLOCK_MONOTONIC
|
| +#endif // __APPLE__
|
| +
|
| +_LIBCPP_BEGIN_NAMESPACE_STD
|
| +
|
| +namespace chrono
|
| +{
|
| +
|
| +// system_clock
|
| +
|
| +const bool system_clock::is_steady;
|
| +
|
| +system_clock::time_point
|
| +system_clock::now() _NOEXCEPT
|
| +{
|
| + timeval tv;
|
| + gettimeofday(&tv, 0);
|
| + return time_point(seconds(tv.tv_sec) + microseconds(tv.tv_usec));
|
| +}
|
| +
|
| +time_t
|
| +system_clock::to_time_t(const time_point& t) _NOEXCEPT
|
| +{
|
| + return time_t(duration_cast<seconds>(t.time_since_epoch()).count());
|
| +}
|
| +
|
| +system_clock::time_point
|
| +system_clock::from_time_t(time_t t) _NOEXCEPT
|
| +{
|
| + return system_clock::time_point(seconds(t));
|
| +}
|
| +
|
| +// steady_clock
|
| +
|
| +const bool steady_clock::is_steady;
|
| +
|
| +#ifdef __APPLE__
|
| +// mach_absolute_time() * MachInfo.numer / MachInfo.denom is the number of
|
| +// nanoseconds since the computer booted up. MachInfo.numer and MachInfo.denom
|
| +// are run time constants supplied by the OS. This clock has no relationship
|
| +// to the Gregorian calendar. It's main use is as a high resolution timer.
|
| +
|
| +// MachInfo.numer / MachInfo.denom is often 1 on the latest equipment. Specialize
|
| +// for that case as an optimization.
|
| +
|
| +#pragma GCC visibility push(hidden)
|
| +
|
| +static
|
| +steady_clock::rep
|
| +steady_simplified()
|
| +{
|
| + return static_cast<steady_clock::rep>(mach_absolute_time());
|
| +}
|
| +
|
| +static
|
| +double
|
| +compute_steady_factor()
|
| +{
|
| + mach_timebase_info_data_t MachInfo;
|
| + mach_timebase_info(&MachInfo);
|
| + return static_cast<double>(MachInfo.numer) / MachInfo.denom;
|
| +}
|
| +
|
| +static
|
| +steady_clock::rep
|
| +steady_full()
|
| +{
|
| + static const double factor = compute_steady_factor();
|
| + return static_cast<steady_clock::rep>(mach_absolute_time() * factor);
|
| +}
|
| +
|
| +typedef steady_clock::rep (*FP)();
|
| +
|
| +static
|
| +FP
|
| +init_steady_clock()
|
| +{
|
| + mach_timebase_info_data_t MachInfo;
|
| + mach_timebase_info(&MachInfo);
|
| + if (MachInfo.numer == MachInfo.denom)
|
| + return &steady_simplified;
|
| + return &steady_full;
|
| +}
|
| +
|
| +#pragma GCC visibility pop
|
| +
|
| +steady_clock::time_point
|
| +steady_clock::now() _NOEXCEPT
|
| +{
|
| + static FP fp = init_steady_clock();
|
| + return time_point(duration(fp()));
|
| +}
|
| +
|
| +#else // __APPLE__
|
| +// FIXME: We assume that clock_gettime(CLOCK_MONOTONIC) works on
|
| +// non-apple systems. Instead, we should check _POSIX_TIMERS and
|
| +// _POSIX_MONOTONIC_CLOCK and fall back to something else if those
|
| +// don't exist.
|
| +
|
| +// Warning: If this is not truly steady, then it is non-conforming. It is
|
| +// better for it to not exist and have the rest of libc++ use system_clock
|
| +// instead.
|
| +
|
| +steady_clock::time_point
|
| +steady_clock::now() _NOEXCEPT
|
| +{
|
| + struct timespec tp;
|
| + if (0 != clock_gettime(CLOCK_MONOTONIC, &tp))
|
| + __throw_system_error(errno, "clock_gettime(CLOCK_MONOTONIC) failed");
|
| + return time_point(seconds(tp.tv_sec) + nanoseconds(tp.tv_nsec));
|
| +}
|
| +#endif // __APPLE__
|
| +
|
| +}
|
| +
|
| +_LIBCPP_END_NAMESPACE_STD
|
|
|
| Property changes on: third_party/libc++/src/chrono.cpp
|
| ___________________________________________________________________
|
| Added: svn:eol-style
|
| + LF
|
|
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|
|