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