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_ID_H
11#define _LIBCPP___THREAD_ID_H
12
13#include <__compare/ordering.h>
14#include <__config>
15#include <__fwd/functional.h>
16#include <__fwd/ostream.h>
17#include <__thread/support.h>
18
19#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
20# pragma GCC system_header
21#endif
22
23_LIBCPP_BEGIN_NAMESPACE_STD
24
25#ifndef _LIBCPP_HAS_NO_THREADS
26class _LIBCPP_EXPORTED_FROM_ABI __thread_id;
27
28namespace this_thread {
29
30_LIBCPP_HIDE_FROM_ABI __thread_id get_id() _NOEXCEPT;
31
32} // namespace this_thread
33
34template <>
35struct hash<__thread_id>;
36
37class _LIBCPP_TEMPLATE_VIS __thread_id {
38 // FIXME: pthread_t is a pointer on Darwin but a long on Linux.
39 // NULL is the no-thread value on Darwin. Someone needs to check
40 // on other platforms. We assume 0 works everywhere for now.
41 __libcpp_thread_id __id_;
42
43 static _LIBCPP_HIDE_FROM_ABI bool
44 __lt_impl(__thread_id __x, __thread_id __y) _NOEXCEPT { // id==0 is always less than any other thread_id
45 if (__x.__id_ == 0)
46 return __y.__id_ != 0;
47 if (__y.__id_ == 0)
48 return false;
49 return __libcpp_thread_id_less(__x.__id_, __y.__id_);
50 }
51
52public:
53 _LIBCPP_HIDE_FROM_ABI __thread_id() _NOEXCEPT : __id_(0) {}
54
55 _LIBCPP_HIDE_FROM_ABI void __reset() { __id_ = 0; }
56
57 friend _LIBCPP_HIDE_FROM_ABI bool operator==(__thread_id __x, __thread_id __y) _NOEXCEPT;
58# if _LIBCPP_STD_VER <= 17
59 friend _LIBCPP_HIDE_FROM_ABI bool operator<(__thread_id __x, __thread_id __y) _NOEXCEPT;
60# else // _LIBCPP_STD_VER <= 17
61 friend _LIBCPP_HIDE_FROM_ABI strong_ordering operator<=>(__thread_id __x, __thread_id __y) noexcept;
62# endif // _LIBCPP_STD_VER <= 17
63
64 template <class _CharT, class _Traits>
65 friend _LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>&
66 operator<<(basic_ostream<_CharT, _Traits>& __os, __thread_id __id);
67
68private:
69 _LIBCPP_HIDE_FROM_ABI __thread_id(__libcpp_thread_id __id) : __id_(__id) {}
70
71 _LIBCPP_HIDE_FROM_ABI friend __libcpp_thread_id __get_underlying_id(const __thread_id __id) { return __id.__id_; }
72
73 friend __thread_id this_thread::get_id() _NOEXCEPT;
74 friend class _LIBCPP_EXPORTED_FROM_ABI thread;
75 friend struct _LIBCPP_TEMPLATE_VIS hash<__thread_id>;
76};
77
78inline _LIBCPP_HIDE_FROM_ABI bool operator==(__thread_id __x, __thread_id __y) _NOEXCEPT {
79 // Don't pass id==0 to underlying routines
80 if (__x.__id_ == 0)
81 return __y.__id_ == 0;
82 if (__y.__id_ == 0)
83 return false;
84 return __libcpp_thread_id_equal(__x.__id_, __y.__id_);
85}
86
87# if _LIBCPP_STD_VER <= 17
88
89inline _LIBCPP_HIDE_FROM_ABI bool operator!=(__thread_id __x, __thread_id __y) _NOEXCEPT { return !(__x == __y); }
90
91inline _LIBCPP_HIDE_FROM_ABI bool operator<(__thread_id __x, __thread_id __y) _NOEXCEPT {
92 return __thread_id::__lt_impl(__x.__id_, __y.__id_);
93}
94
95inline _LIBCPP_HIDE_FROM_ABI bool operator<=(__thread_id __x, __thread_id __y) _NOEXCEPT { return !(__y < __x); }
96inline _LIBCPP_HIDE_FROM_ABI bool operator>(__thread_id __x, __thread_id __y) _NOEXCEPT { return __y < __x; }
97inline _LIBCPP_HIDE_FROM_ABI bool operator>=(__thread_id __x, __thread_id __y) _NOEXCEPT { return !(__x < __y); }
98
99# else // _LIBCPP_STD_VER <= 17
100
101inline _LIBCPP_HIDE_FROM_ABI strong_ordering operator<=>(__thread_id __x, __thread_id __y) noexcept {
102 if (__x == __y)
103 return strong_ordering::equal;
104 if (__thread_id::__lt_impl(__x, __y))
105 return strong_ordering::less;
106 return strong_ordering::greater;
107}
108
109# endif // _LIBCPP_STD_VER <= 17
110
111namespace this_thread {
112
113inline _LIBCPP_HIDE_FROM_ABI __thread_id get_id() _NOEXCEPT { return __libcpp_thread_get_current_id(); }
114
115} // namespace this_thread
116
117#endif // !_LIBCPP_HAS_NO_THREADS
118
119_LIBCPP_END_NAMESPACE_STD
120
121#endif // _LIBCPP___THREAD_ID_H
122