//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#if defined(__MVS__)
// As part of monotonic clock support on z/OS we need macro _LARGE_TIME_API
// to be defined before any system header to include definition of struct timespec64.
# define _LARGE_TIME_API
#endif
#include <__system_error/system_error.h>
#include <cerrno> // errno
#include <chrono>
#if defined(__MVS__)
# include <__support/ibm/gettod_zos.h> // gettimeofdayMonotonic
#endif
#include "include/apple_availability.h"
#include <time.h> // clock_gettime and CLOCK_{MONOTONIC,REALTIME,MONOTONIC_RAW}
#if __has_include(<unistd.h>)
# include <unistd.h> // _POSIX_TIMERS
#endif
#if __has_include(<sys/time.h>)
# include <sys/time.h> // for gettimeofday and timeval
#endif
// OpenBSD and GPU do not have a fully conformant suite of POSIX timers, but
// it does have clock_gettime and CLOCK_MONOTONIC which is all we need.
#if defined(__APPLE__) || defined(__gnu_hurd__) || defined(__OpenBSD__) || defined(__AMDGPU__) || \
defined(__NVPTX__) || (defined(_POSIX_TIMERS) && _POSIX_TIMERS > 0)
# define _LIBCPP_HAS_CLOCK_GETTIME
#endif
#if defined(_LIBCPP_WIN32API)
# define WIN32_LEAN_AND_MEAN
# define VC_EXTRA_LEAN
# include <windows.h>
# if _WIN32_WINNT >= _WIN32_WINNT_WIN8
# include <winapifamily.h>
# endif
#endif // defined(_LIBCPP_WIN32API)
#if defined(__Fuchsia__)
# include <zircon/syscalls.h>
#endif
#if __has_include(<mach/mach_time.h>)
# include <mach/mach_time.h>
#endif
#if defined(__ELF__) && defined(_LIBCPP_LINK_RT_LIB)
# pragma comment(lib, "rt")
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
namespace chrono {
//
// system_clock
//
#if defined(_LIBCPP_WIN32API)
# if _WIN32_WINNT < _WIN32_WINNT_WIN8
namespace {
typedef void(WINAPI* GetSystemTimeAsFileTimePtr)(LPFILETIME);
class GetSystemTimeInit {
public:
GetSystemTimeInit() {
fp = (GetSystemTimeAsFileTimePtr)(void*)GetProcAddress(
GetModuleHandleW(L"kernel32.dll"), "GetSystemTimePreciseAsFileTime");
if (fp == nullptr)
fp = GetSystemTimeAsFileTime;
}
GetSystemTimeAsFileTimePtr fp;
};
// Pretend we're inside a system header so the compiler doesn't flag the use of the init_priority
// attribute with a value that's reserved for the implementation (we're the implementation).
# include "chrono_system_time_init.h"
} // namespace
# endif
static system_clock::time_point __libcpp_system_clock_now() {
// FILETIME is in 100ns units
using filetime_duration =
std::chrono::duration<__int64, std::ratio_multiply<std::ratio<100, 1>, nanoseconds::period>>;
// The Windows epoch is Jan 1 1601, the Unix epoch Jan 1 1970.
static constexpr const seconds nt_to_unix_epoch{11644473600};
FILETIME ft;
# if (_WIN32_WINNT >= _WIN32_WINNT_WIN8 && WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)) || \
(_WIN32_WINNT >= _WIN32_WINNT_WIN10)
GetSystemTimePreciseAsFileTime(&ft);
# elif !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)
GetSystemTimeAsFileTime(&ft);
# else
GetSystemTimeAsFileTimeFunc.fp(&ft);
# endif
filetime_duration d{(static_cast<__int64>(ft.dwHighDateTime) << 32) | static_cast<__int64>(ft.dwLowDateTime)};
return system_clock::time_point(duration_cast<system_clock::duration>(d - nt_to_unix_epoch));
}
#elif defined(_LIBCPP_HAS_CLOCK_GETTIME)
static system_clock::time_point __libcpp_system_clock_now() {
struct timespec tp;
if (0 != clock_gettime(CLOCK_REALTIME, &tp))
__throw_system_error(errno, "clock_gettime(CLOCK_REALTIME) failed");
return system_clock::time_point(seconds(tp.tv_sec) + microseconds(tp.tv_nsec / 1000));
}
#else
static system_clock::time_point __libcpp_system_clock_now() {
timeval tv;
gettimeofday(&tv, 0);
return system_clock::time_point(seconds(tv.tv_sec) + microseconds(tv.tv_usec));
}
#endif
const bool system_clock::is_steady;
system_clock::time_point system_clock::now() noexcept { return __libcpp_system_clock_now(); }
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
//
// 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.
//
#ifndef _LIBCPP_HAS_NO_MONOTONIC_CLOCK
# if defined(__APPLE__)
// On Apple platforms, only CLOCK_UPTIME_RAW, CLOCK_MONOTONIC_RAW or
// mach_absolute_time are able to time functions in the nanosecond range.
// Furthermore, only CLOCK_MONOTONIC_RAW is truly monotonic, because it
// also counts cycles when the system is asleep. Thus, it is the only
// acceptable implementation of steady_clock.
static steady_clock::time_point __libcpp_steady_clock_now() {
struct timespec tp;
if (0 != clock_gettime(CLOCK_MONOTONIC_RAW, &tp))
__throw_system_error(errno, "clock_gettime(CLOCK_MONOTONIC_RAW) failed");
return steady_clock::time_point(seconds(tp.tv_sec) + nanoseconds(tp.tv_nsec));
}
# elif defined(_LIBCPP_WIN32API)
// https://msdn.microsoft.com/en-us/library/windows/desktop/ms644905(v=vs.85).aspx says:
// If the function fails, the return value is zero. <snip>
// On systems that run Windows XP or later, the function will always succeed
// and will thus never return zero.
static LARGE_INTEGER __QueryPerformanceFrequency() {
LARGE_INTEGER val;
(void)QueryPerformanceFrequency(&val);
return val;
}
static steady_clock::time_point __libcpp_steady_clock_now() {
static const LARGE_INTEGER freq = __QueryPerformanceFrequency();
LARGE_INTEGER counter;
(void)QueryPerformanceCounter(&counter);
auto seconds = counter.QuadPart / freq.QuadPart;
auto fractions = counter.QuadPart % freq.QuadPart;
auto dur = seconds * nano::den + fractions * nano::den / freq.QuadPart;
return steady_clock::time_point(steady_clock::duration(dur));
}
# elif defined(__MVS__)
static steady_clock::time_point __libcpp_steady_clock_now() {
struct timespec64 ts;
if (0 != gettimeofdayMonotonic(&ts))
__throw_system_error(errno, "failed to obtain time of day");
return steady_clock::time_point(seconds(ts.tv_sec) + nanoseconds(ts.tv_nsec));
}
# elif defined(__Fuchsia__)
static steady_clock::time_point __libcpp_steady_clock_now() noexcept {
// Implicitly link against the vDSO system call ABI without
// requiring the final link to specify -lzircon explicitly when
// statically linking libc++.
# pragma comment(lib, "zircon")
return steady_clock::time_point(nanoseconds(_zx_clock_get_monotonic()));
}
# elif defined(_LIBCPP_HAS_CLOCK_GETTIME)
static steady_clock::time_point __libcpp_steady_clock_now() {
struct timespec tp;
if (0 != clock_gettime(CLOCK_MONOTONIC, &tp))
__throw_system_error(errno, "clock_gettime(CLOCK_MONOTONIC) failed");
return steady_clock::time_point(seconds(tp.tv_sec) + nanoseconds(tp.tv_nsec));
}
# else
# error "Monotonic clock not implemented on this platform"
# endif
const bool steady_clock::is_steady;
steady_clock::time_point steady_clock::now() noexcept { return __libcpp_steady_clock_now(); }
#endif // !_LIBCPP_HAS_NO_MONOTONIC_CLOCK
} // namespace chrono
_LIBCPP_END_NAMESPACE_STD
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