xref: /openbsd-src/gnu/llvm/libcxx/include/__chrono/convert_to_timespec.h (revision 4bdff4bed0e3d54e55670334c7d0077db4170f86)
1*4bdff4beSrobert // -*- C++ -*-
2*4bdff4beSrobert //===----------------------------------------------------------------------===//
3*4bdff4beSrobert //
4*4bdff4beSrobert // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5*4bdff4beSrobert // See https://llvm.org/LICENSE.txt for license information.
6*4bdff4beSrobert // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7*4bdff4beSrobert //
8*4bdff4beSrobert //===----------------------------------------------------------------------===//
9*4bdff4beSrobert 
10*4bdff4beSrobert #ifndef _LIBCPP___CHRONO_CONVERT_TO_TIMESPEC_H
11*4bdff4beSrobert #define _LIBCPP___CHRONO_CONVERT_TO_TIMESPEC_H
12*4bdff4beSrobert 
13*4bdff4beSrobert #include <__chrono/duration.h>
14*4bdff4beSrobert #include <__config>
15*4bdff4beSrobert #include <limits>
16*4bdff4beSrobert 
17*4bdff4beSrobert #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
18*4bdff4beSrobert #  pragma GCC system_header
19*4bdff4beSrobert #endif
20*4bdff4beSrobert 
21*4bdff4beSrobert _LIBCPP_PUSH_MACROS
22*4bdff4beSrobert #include <__undef_macros>
23*4bdff4beSrobert 
24*4bdff4beSrobert _LIBCPP_BEGIN_NAMESPACE_STD
25*4bdff4beSrobert 
26*4bdff4beSrobert // Convert a nanoseconds duration to the given TimeSpec type, which must have
27*4bdff4beSrobert // the same properties as std::timespec.
28*4bdff4beSrobert template <class _TimeSpec>
29*4bdff4beSrobert _LIBCPP_HIDE_FROM_ABI inline
__convert_to_timespec(const chrono::nanoseconds & __ns)30*4bdff4beSrobert _TimeSpec __convert_to_timespec(const chrono::nanoseconds& __ns)
31*4bdff4beSrobert {
32*4bdff4beSrobert   using namespace chrono;
33*4bdff4beSrobert   seconds __s = duration_cast<seconds>(__ns);
34*4bdff4beSrobert   _TimeSpec __ts;
35*4bdff4beSrobert   typedef decltype(__ts.tv_sec) __ts_sec;
36*4bdff4beSrobert   const __ts_sec __ts_sec_max = numeric_limits<__ts_sec>::max();
37*4bdff4beSrobert 
38*4bdff4beSrobert   if (__s.count() < __ts_sec_max)
39*4bdff4beSrobert   {
40*4bdff4beSrobert     __ts.tv_sec = static_cast<__ts_sec>(__s.count());
41*4bdff4beSrobert     __ts.tv_nsec = static_cast<decltype(__ts.tv_nsec)>((__ns - __s).count());
42*4bdff4beSrobert   }
43*4bdff4beSrobert   else
44*4bdff4beSrobert   {
45*4bdff4beSrobert     __ts.tv_sec = __ts_sec_max;
46*4bdff4beSrobert     __ts.tv_nsec = 999999999; // (10^9 - 1)
47*4bdff4beSrobert   }
48*4bdff4beSrobert 
49*4bdff4beSrobert   return __ts;
50*4bdff4beSrobert }
51*4bdff4beSrobert 
52*4bdff4beSrobert _LIBCPP_END_NAMESPACE_STD
53*4bdff4beSrobert 
54*4bdff4beSrobert _LIBCPP_POP_MACROS
55*4bdff4beSrobert 
56*4bdff4beSrobert #endif // _LIBCPP___CHRONO_CONVERT_TO_TIMESPEC_H
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