llvm-project/libcxx/include/__chrono/convert_to_timespec.h

56 lines
1.5 KiB
C++

// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP___CHRONO_CONVERT_TO_TIMESPEC_H
#define _LIBCPP___CHRONO_CONVERT_TO_TIMESPEC_H
#include <__chrono/duration.h>
#include <__config>
#include <limits>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_PUSH_MACROS
#include <__undef_macros>
_LIBCPP_BEGIN_NAMESPACE_STD
// Convert a nanoseconds duration to the given TimeSpec type, which must have
// the same properties as std::timespec.
template <class _TimeSpec>
_LIBCPP_HIDE_FROM_ABI inline
_TimeSpec __convert_to_timespec(const chrono::nanoseconds& __ns)
{
using namespace chrono;
seconds __s = duration_cast<seconds>(__ns);
_TimeSpec __ts;
typedef decltype(__ts.tv_sec) __ts_sec;
const __ts_sec __ts_sec_max = numeric_limits<__ts_sec>::max();
if (__s.count() < __ts_sec_max)
{
__ts.tv_sec = static_cast<__ts_sec>(__s.count());
__ts.tv_nsec = static_cast<decltype(__ts.tv_nsec)>((__ns - __s).count());
}
else
{
__ts.tv_sec = __ts_sec_max;
__ts.tv_nsec = 999999999; // (10^9 - 1)
}
return __ts;
}
_LIBCPP_END_NAMESPACE_STD
_LIBCPP_POP_MACROS
#endif // _LIBCPP___CHRONO_CONVERT_TO_TIMESPEC_H