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#include <__assert>
10#include <__system_error/throw_system_error.h>
11#include <__thread/id.h>
12#include <__utility/exception_guard.h>
13#include <limits>
14#include <mutex>
15
16#include "include/atomic_support.h"
17
18#if defined(__ELF__) && defined(_LIBCPP_LINK_PTHREAD_LIB)
19# pragma comment(lib, "pthread")
20#endif
21
22_LIBCPP_PUSH_MACROS
23#include <__undef_macros>
24
25_LIBCPP_BEGIN_NAMESPACE_STD
26
27// ~mutex is defined elsewhere
28
29void mutex::lock() {
30 int ec = __libcpp_mutex_lock(&__m_);
31 if (ec)
32 std::__throw_system_error(ec, "mutex lock failed");
33}
34
35bool mutex::try_lock() noexcept { return __libcpp_mutex_trylock(&__m_); }
36
37void mutex::unlock() noexcept {
38 int ec = __libcpp_mutex_unlock(&__m_);
39 (void)ec;
40 _LIBCPP_ASSERT_VALID_EXTERNAL_API_CALL(
41 ec == 0, "call to mutex::unlock failed. A possible reason is that the mutex wasn't locked");
42}
43
44// recursive_mutex
45
46recursive_mutex::recursive_mutex() {
47 int ec = __libcpp_recursive_mutex_init(&__m_);
48 if (ec)
49 std::__throw_system_error(ec, "recursive_mutex constructor failed");
50}
51
52recursive_mutex::~recursive_mutex() {
53 int e = __libcpp_recursive_mutex_destroy(&__m_);
54 (void)e;
55 _LIBCPP_ASSERT_VALID_EXTERNAL_API_CALL(e == 0, "call to ~recursive_mutex() failed");
56}
57
58void recursive_mutex::lock() {
59 int ec = __libcpp_recursive_mutex_lock(&__m_);
60 if (ec)
61 std::__throw_system_error(ec, "recursive_mutex lock failed");
62}
63
64void recursive_mutex::unlock() noexcept {
65 int e = __libcpp_recursive_mutex_unlock(&__m_);
66 (void)e;
67 _LIBCPP_ASSERT_VALID_EXTERNAL_API_CALL(
68 e == 0, "call to recursive_mutex::unlock() failed. A possible reason is that the mutex wasn't locked");
69}
70
71bool recursive_mutex::try_lock() noexcept { return __libcpp_recursive_mutex_trylock(&__m_); }
72
73// timed_mutex
74
75timed_mutex::timed_mutex() : __locked_(false) {}
76
77timed_mutex::~timed_mutex() { lock_guard<mutex> _(__m_); }
78
79void timed_mutex::lock() {
80 unique_lock<mutex> lk(__m_);
81 while (__locked_)
82 __cv_.wait(lk);
83 __locked_ = true;
84}
85
86bool timed_mutex::try_lock() noexcept {
87 unique_lock<mutex> lk(__m_, try_to_lock);
88 if (lk.owns_lock() && !__locked_) {
89 __locked_ = true;
90 return true;
91 }
92 return false;
93}
94
95void timed_mutex::unlock() noexcept {
96 lock_guard<mutex> _(__m_);
97 __locked_ = false;
98 __cv_.notify_one();
99}
100
101// recursive_timed_mutex
102
103recursive_timed_mutex::recursive_timed_mutex() : __count_(0), __id_{} {}
104
105recursive_timed_mutex::~recursive_timed_mutex() { lock_guard<mutex> _(__m_); }
106
107void recursive_timed_mutex::lock() {
108 __thread_id id = this_thread::get_id();
109 unique_lock<mutex> lk(__m_);
110 if (id == __id_) {
111 if (__count_ == numeric_limits<size_t>::max())
112 std::__throw_system_error(EAGAIN, "recursive_timed_mutex lock limit reached");
113 ++__count_;
114 return;
115 }
116 while (__count_ != 0)
117 __cv_.wait(lk);
118 __count_ = 1;
119 __id_ = id;
120}
121
122bool recursive_timed_mutex::try_lock() noexcept {
123 __thread_id id = this_thread::get_id();
124 unique_lock<mutex> lk(__m_, try_to_lock);
125 if (lk.owns_lock() && (__count_ == 0 || id == __id_)) {
126 if (__count_ == numeric_limits<size_t>::max())
127 return false;
128 ++__count_;
129 __id_ = id;
130 return true;
131 }
132 return false;
133}
134
135void recursive_timed_mutex::unlock() noexcept {
136 unique_lock<mutex> lk(__m_);
137 if (--__count_ == 0) {
138 __id_.__reset();
139 lk.unlock();
140 __cv_.notify_one();
141 }
142}
143
144_LIBCPP_END_NAMESPACE_STD
145
146_LIBCPP_POP_MACROS
147

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source code of libcxx/src/mutex.cpp