1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8
9 #ifndef _LIBCPP___MUTEX_UNIQUE_LOCK_H
10 #define _LIBCPP___MUTEX_UNIQUE_LOCK_H
11
12 #include <__chrono/duration.h>
13 #include <__chrono/time_point.h>
14 #include <__config>
15 #include <__memory/addressof.h>
16 #include <__mutex/tag_types.h>
17 #include <__system_error/system_error.h>
18 #include <__utility/swap.h>
19 #include <cerrno>
20
21 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
22 # pragma GCC system_header
23 #endif
24
25 #ifndef _LIBCPP_HAS_NO_THREADS
26
27 _LIBCPP_BEGIN_NAMESPACE_STD
28
29 template <class _Mutex>
30 class _LIBCPP_TEMPLATE_VIS unique_lock {
31 public:
32 typedef _Mutex mutex_type;
33
34 private:
35 mutex_type* __m_;
36 bool __owns_;
37
38 public:
unique_lock()39 _LIBCPP_NODISCARD _LIBCPP_HIDE_FROM_ABI unique_lock() _NOEXCEPT : __m_(nullptr), __owns_(false) {}
unique_lock(mutex_type & __m)40 _LIBCPP_NODISCARD _LIBCPP_HIDE_FROM_ABI explicit unique_lock(mutex_type& __m)
41 : __m_(std::addressof(__m)), __owns_(true) {
42 __m_->lock();
43 }
44
unique_lock(mutex_type & __m,defer_lock_t)45 _LIBCPP_NODISCARD _LIBCPP_HIDE_FROM_ABI unique_lock(mutex_type& __m, defer_lock_t) _NOEXCEPT
46 : __m_(std::addressof(__m)),
47 __owns_(false) {}
48
unique_lock(mutex_type & __m,try_to_lock_t)49 _LIBCPP_NODISCARD _LIBCPP_HIDE_FROM_ABI unique_lock(mutex_type& __m, try_to_lock_t)
50 : __m_(std::addressof(__m)), __owns_(__m.try_lock()) {}
51
unique_lock(mutex_type & __m,adopt_lock_t)52 _LIBCPP_NODISCARD _LIBCPP_HIDE_FROM_ABI unique_lock(mutex_type& __m, adopt_lock_t)
53 : __m_(std::addressof(__m)), __owns_(true) {}
54
55 template <class _Clock, class _Duration>
unique_lock(mutex_type & __m,const chrono::time_point<_Clock,_Duration> & __t)56 _LIBCPP_NODISCARD _LIBCPP_HIDE_FROM_ABI unique_lock(mutex_type& __m, const chrono::time_point<_Clock, _Duration>& __t)
57 : __m_(std::addressof(__m)), __owns_(__m.try_lock_until(__t)) {}
58
59 template <class _Rep, class _Period>
unique_lock(mutex_type & __m,const chrono::duration<_Rep,_Period> & __d)60 _LIBCPP_NODISCARD _LIBCPP_HIDE_FROM_ABI unique_lock(mutex_type& __m, const chrono::duration<_Rep, _Period>& __d)
61 : __m_(std::addressof(__m)), __owns_(__m.try_lock_for(__d)) {}
62
~unique_lock()63 _LIBCPP_HIDE_FROM_ABI ~unique_lock() {
64 if (__owns_)
65 __m_->unlock();
66 }
67
68 unique_lock(unique_lock const&) = delete;
69 unique_lock& operator=(unique_lock const&) = delete;
70
unique_lock(unique_lock && __u)71 _LIBCPP_NODISCARD _LIBCPP_HIDE_FROM_ABI unique_lock(unique_lock&& __u) _NOEXCEPT
72 : __m_(__u.__m_),
73 __owns_(__u.__owns_) {
74 __u.__m_ = nullptr;
75 __u.__owns_ = false;
76 }
77
78 _LIBCPP_HIDE_FROM_ABI unique_lock& operator=(unique_lock&& __u) _NOEXCEPT {
79 if (__owns_)
80 __m_->unlock();
81
82 __m_ = __u.__m_;
83 __owns_ = __u.__owns_;
84 __u.__m_ = nullptr;
85 __u.__owns_ = false;
86 return *this;
87 }
88
89 void lock();
90 bool try_lock();
91
92 template <class _Rep, class _Period>
93 bool try_lock_for(const chrono::duration<_Rep, _Period>& __d);
94
95 template <class _Clock, class _Duration>
96 bool try_lock_until(const chrono::time_point<_Clock, _Duration>& __t);
97
98 void unlock();
99
swap(unique_lock & __u)100 _LIBCPP_HIDE_FROM_ABI void swap(unique_lock& __u) _NOEXCEPT {
101 std::swap(__m_, __u.__m_);
102 std::swap(__owns_, __u.__owns_);
103 }
104
release()105 _LIBCPP_HIDE_FROM_ABI mutex_type* release() _NOEXCEPT {
106 mutex_type* __m = __m_;
107 __m_ = nullptr;
108 __owns_ = false;
109 return __m;
110 }
111
owns_lock()112 _LIBCPP_HIDE_FROM_ABI bool owns_lock() const _NOEXCEPT { return __owns_; }
113 _LIBCPP_HIDE_FROM_ABI explicit operator bool() const _NOEXCEPT { return __owns_; }
mutex()114 _LIBCPP_HIDE_FROM_ABI mutex_type* mutex() const _NOEXCEPT { return __m_; }
115 };
116 _LIBCPP_CTAD_SUPPORTED_FOR_TYPE(unique_lock);
117
118 template <class _Mutex>
lock()119 void unique_lock<_Mutex>::lock() {
120 if (__m_ == nullptr)
121 __throw_system_error(EPERM, "unique_lock::lock: references null mutex");
122 if (__owns_)
123 __throw_system_error(EDEADLK, "unique_lock::lock: already locked");
124 __m_->lock();
125 __owns_ = true;
126 }
127
128 template <class _Mutex>
try_lock()129 bool unique_lock<_Mutex>::try_lock() {
130 if (__m_ == nullptr)
131 __throw_system_error(EPERM, "unique_lock::try_lock: references null mutex");
132 if (__owns_)
133 __throw_system_error(EDEADLK, "unique_lock::try_lock: already locked");
134 __owns_ = __m_->try_lock();
135 return __owns_;
136 }
137
138 template <class _Mutex>
139 template <class _Rep, class _Period>
try_lock_for(const chrono::duration<_Rep,_Period> & __d)140 bool unique_lock<_Mutex>::try_lock_for(const chrono::duration<_Rep, _Period>& __d) {
141 if (__m_ == nullptr)
142 __throw_system_error(EPERM, "unique_lock::try_lock_for: references null mutex");
143 if (__owns_)
144 __throw_system_error(EDEADLK, "unique_lock::try_lock_for: already locked");
145 __owns_ = __m_->try_lock_for(__d);
146 return __owns_;
147 }
148
149 template <class _Mutex>
150 template <class _Clock, class _Duration>
try_lock_until(const chrono::time_point<_Clock,_Duration> & __t)151 bool unique_lock<_Mutex>::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t) {
152 if (__m_ == nullptr)
153 __throw_system_error(EPERM, "unique_lock::try_lock_until: references null mutex");
154 if (__owns_)
155 __throw_system_error(EDEADLK, "unique_lock::try_lock_until: already locked");
156 __owns_ = __m_->try_lock_until(__t);
157 return __owns_;
158 }
159
160 template <class _Mutex>
unlock()161 void unique_lock<_Mutex>::unlock() {
162 if (!__owns_)
163 __throw_system_error(EPERM, "unique_lock::unlock: not locked");
164 __m_->unlock();
165 __owns_ = false;
166 }
167
168 template <class _Mutex>
swap(unique_lock<_Mutex> & __x,unique_lock<_Mutex> & __y)169 inline _LIBCPP_HIDE_FROM_ABI void swap(unique_lock<_Mutex>& __x, unique_lock<_Mutex>& __y) _NOEXCEPT {
170 __x.swap(__y);
171 }
172
173 _LIBCPP_END_NAMESPACE_STD
174
175 #endif // _LIBCPP_HAS_NO_THREADS
176
177 #endif // _LIBCPP___MUTEX_UNIQUE_LOCK_H
178