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___THREAD_THIS_THREAD_H
11#define _LIBCPP___THREAD_THIS_THREAD_H
12
13#include <__chrono/duration.h>
14#include <__chrono/steady_clock.h>
15#include <__chrono/time_point.h>
16#include <__condition_variable/condition_variable.h>
17#include <__config>
18#include <__mutex/mutex.h>
19#include <__mutex/unique_lock.h>
20#include <__thread/support.h>
21
22#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
23# pragma GCC system_header
24#endif
25
26_LIBCPP_PUSH_MACROS
27#include <__undef_macros>
28
29_LIBCPP_BEGIN_NAMESPACE_STD
30
31namespace this_thread {
32
33#if _LIBCPP_HAS_THREADS
34
35_LIBCPP_BEGIN_EXPLICIT_ABI_ANNOTATIONS
36_LIBCPP_EXPORTED_FROM_ABI void sleep_for(const chrono::nanoseconds& __ns);
37_LIBCPP_END_EXPLICIT_ABI_ANNOTATIONS
38
39template <class _Rep, class _Period>
40_LIBCPP_HIDE_FROM_ABI void sleep_for(const chrono::duration<_Rep, _Period>& __d) {
41 if (__d > chrono::duration<_Rep, _Period>::zero()) {
42 // The standard guarantees a 64bit signed integer resolution for nanoseconds,
43 // so use INT64_MAX / 1e9 as cut-off point. Use a constant to avoid <climits>
44 // and issues with long double folding on PowerPC with GCC.
45 _LIBCPP_CONSTEXPR chrono::duration<long double> __max = chrono::duration<long double>(9223372036.0L);
46 chrono::nanoseconds __ns;
47 if (__d < __max) {
48 __ns = chrono::duration_cast<chrono::nanoseconds>(__d);
49 if (__ns < __d)
50 ++__ns;
51 } else
52 __ns = chrono::nanoseconds::max();
53 this_thread::sleep_for(__ns);
54 }
55}
56
57template <class _Clock, class _Duration>
58_LIBCPP_HIDE_FROM_ABI void sleep_until(const chrono::time_point<_Clock, _Duration>& __t) {
59 mutex __mut;
60 condition_variable __cv;
61 unique_lock<mutex> __lk(__mut);
62 while (_Clock::now() < __t)
63 __cv.wait_until(__lk, __t);
64}
65
66template <class _Duration>
67inline _LIBCPP_HIDE_FROM_ABI void sleep_until(const chrono::time_point<chrono::steady_clock, _Duration>& __t) {
68 this_thread::sleep_for(__t - chrono::steady_clock::now());
69}
70
71inline _LIBCPP_HIDE_FROM_ABI void yield() _NOEXCEPT { __libcpp_thread_yield(); }
72
73#endif // _LIBCPP_HAS_THREADS
74
75} // namespace this_thread
76
77_LIBCPP_END_NAMESPACE_STD
78
79_LIBCPP_POP_MACROS
80
81#endif // _LIBCPP___THREAD_THIS_THREAD_H
82