1 | /* |
2 | * Copyright Andrey Semashev 2007 - 2021. |
3 | * Distributed under the Boost Software License, Version 1.0. |
4 | * (See accompanying file LICENSE_1_0.txt or copy at |
5 | * http://www.boost.org/LICENSE_1_0.txt) |
6 | */ |
7 | /*! |
8 | * \file event.cpp |
9 | * \author Andrey Semashev |
10 | * \date 24.07.2011 |
11 | * |
12 | * \brief This header is the Boost.Log library implementation, see the library documentation |
13 | * at http://www.boost.org/doc/libs/release/libs/log/doc/html/index.html. |
14 | */ |
15 | |
16 | #include <boost/log/detail/config.hpp> |
17 | |
18 | #ifndef BOOST_LOG_NO_THREADS |
19 | |
20 | #include <boost/assert.hpp> |
21 | #include <boost/cstdint.hpp> |
22 | #include <boost/throw_exception.hpp> |
23 | #include <boost/log/detail/event.hpp> |
24 | #include <boost/log/exceptions.hpp> |
25 | |
26 | #if defined(BOOST_LOG_EVENT_USE_ATOMIC) |
27 | |
28 | #include <boost/memory_order.hpp> |
29 | #include <boost/atomic/atomic.hpp> |
30 | #include <boost/atomic/fences.hpp> |
31 | |
32 | #elif defined(BOOST_LOG_EVENT_USE_POSIX_SEMAPHORE) |
33 | |
34 | #include <errno.h> |
35 | #include <semaphore.h> |
36 | #include <boost/memory_order.hpp> |
37 | #include <boost/atomic/fences.hpp> |
38 | |
39 | #elif defined(BOOST_LOG_EVENT_USE_WINAPI) |
40 | |
41 | #include <windows.h> |
42 | #include <boost/memory_order.hpp> |
43 | #include <boost/atomic/atomic.hpp> |
44 | #include <boost/atomic/fences.hpp> |
45 | |
46 | #else |
47 | |
48 | #include <boost/thread/locks.hpp> |
49 | |
50 | #endif |
51 | |
52 | #include <boost/log/detail/header.hpp> |
53 | |
54 | namespace boost { |
55 | |
56 | BOOST_LOG_OPEN_NAMESPACE |
57 | |
58 | namespace aux { |
59 | |
60 | #if defined(BOOST_LOG_EVENT_USE_ATOMIC) |
61 | |
62 | //! Waits for the object to become signalled |
63 | BOOST_LOG_API void atomic_based_event::wait() |
64 | { |
65 | while (m_state.exchange(v: 0u, order: boost::memory_order_acq_rel) == 0u) |
66 | { |
67 | m_state.wait(old_val: 0u, order: boost::memory_order_relaxed); |
68 | } |
69 | } |
70 | |
71 | //! Sets the object to a signalled state |
72 | BOOST_LOG_API void atomic_based_event::set_signalled() |
73 | { |
74 | if (m_state.load(order: boost::memory_order_relaxed) != 0u) |
75 | { |
76 | boost::atomic_thread_fence(order: boost::memory_order_release); |
77 | } |
78 | else if (m_state.exchange(v: 1u, order: boost::memory_order_release) == 0u) |
79 | { |
80 | m_state.notify_one(); |
81 | } |
82 | } |
83 | |
84 | #elif defined(BOOST_LOG_EVENT_USE_POSIX_SEMAPHORE) |
85 | |
86 | //! Default constructor |
87 | BOOST_LOG_API sem_based_event::sem_based_event() : m_state() |
88 | { |
89 | if (BOOST_UNLIKELY(sem_init(&m_semaphore, 0, 0) != 0)) |
90 | { |
91 | const int err = errno; |
92 | BOOST_LOG_THROW_DESCR_PARAMS(system_error, "Failed to initialize semaphore" , (err)); |
93 | } |
94 | } |
95 | |
96 | //! Destructor |
97 | BOOST_LOG_API sem_based_event::~sem_based_event() |
98 | { |
99 | BOOST_VERIFY(sem_destroy(&m_semaphore) == 0); |
100 | } |
101 | |
102 | //! Waits for the object to become signalled |
103 | BOOST_LOG_API void sem_based_event::wait() |
104 | { |
105 | boost::atomic_thread_fence(boost::memory_order_acq_rel); |
106 | while (true) |
107 | { |
108 | if (sem_wait(&m_semaphore) != 0) |
109 | { |
110 | const int err = errno; |
111 | if (BOOST_UNLIKELY(err != EINTR)) |
112 | { |
113 | BOOST_LOG_THROW_DESCR_PARAMS(system_error, "Failed to block on the semaphore" , (err)); |
114 | } |
115 | } |
116 | else |
117 | break; |
118 | } |
119 | m_state.clear(boost::memory_order_relaxed); |
120 | } |
121 | |
122 | //! Sets the object to a signalled state |
123 | BOOST_LOG_API void sem_based_event::set_signalled() |
124 | { |
125 | if (!m_state.test_and_set(boost::memory_order_release)) |
126 | { |
127 | if (BOOST_UNLIKELY(sem_post(&m_semaphore) != 0)) |
128 | { |
129 | const int err = errno; |
130 | BOOST_LOG_THROW_DESCR_PARAMS(system_error, "Failed to wake the blocked thread" , (err)); |
131 | } |
132 | } |
133 | } |
134 | |
135 | #elif defined(BOOST_LOG_EVENT_USE_WINAPI) |
136 | |
137 | //! Default constructor |
138 | BOOST_LOG_API winapi_based_event::winapi_based_event() : |
139 | m_state(0u), |
140 | m_event(NULL) |
141 | { |
142 | if (!m_state.has_native_wait_notify()) |
143 | { |
144 | m_event = CreateEventA(NULL, false, false, NULL); |
145 | if (BOOST_UNLIKELY(!m_event)) |
146 | { |
147 | const DWORD err = GetLastError(); |
148 | BOOST_LOG_THROW_DESCR_PARAMS(system_error, "Failed to create Windows event" , (err)); |
149 | } |
150 | } |
151 | } |
152 | |
153 | //! Destructor |
154 | BOOST_LOG_API winapi_based_event::~winapi_based_event() |
155 | { |
156 | if (!!m_event) |
157 | { |
158 | BOOST_VERIFY(CloseHandle(m_event) != 0); |
159 | } |
160 | } |
161 | |
162 | //! Waits for the object to become signalled |
163 | BOOST_LOG_API void winapi_based_event::wait() |
164 | { |
165 | if (!m_event) |
166 | { |
167 | while (m_state.exchange(0u, boost::memory_order_acq_rel) == 0u) |
168 | { |
169 | m_state.wait(0u, boost::memory_order_relaxed); |
170 | } |
171 | } |
172 | else |
173 | { |
174 | while (m_state.exchange(0u, boost::memory_order_acq_rel) == 0u) |
175 | { |
176 | if (BOOST_UNLIKELY(WaitForSingleObject(m_event, INFINITE) != 0)) |
177 | { |
178 | const DWORD err = GetLastError(); |
179 | BOOST_LOG_THROW_DESCR_PARAMS(system_error, "Failed to block on Windows event" , (err)); |
180 | } |
181 | } |
182 | } |
183 | } |
184 | |
185 | //! Sets the object to a signalled state |
186 | BOOST_LOG_API void winapi_based_event::set_signalled() |
187 | { |
188 | if (m_state.load(boost::memory_order_relaxed) != 0u) |
189 | { |
190 | boost::atomic_thread_fence(boost::memory_order_release); |
191 | } |
192 | else if (m_state.exchange(1u, boost::memory_order_release) == 0u) |
193 | { |
194 | if (!m_event) |
195 | { |
196 | m_state.notify_one(); |
197 | } |
198 | else |
199 | { |
200 | if (BOOST_UNLIKELY(SetEvent(m_event) == 0)) |
201 | { |
202 | const DWORD err = GetLastError(); |
203 | m_state.store(0u, boost::memory_order_relaxed); |
204 | BOOST_LOG_THROW_DESCR_PARAMS(system_error, "Failed to wake the blocked thread" , (err)); |
205 | } |
206 | } |
207 | } |
208 | } |
209 | |
210 | #else |
211 | |
212 | //! Default constructor |
213 | BOOST_LOG_API generic_event::generic_event() : m_state(false) |
214 | { |
215 | } |
216 | |
217 | //! Destructor |
218 | BOOST_LOG_API generic_event::~generic_event() |
219 | { |
220 | } |
221 | |
222 | //! Waits for the object to become signalled |
223 | BOOST_LOG_API void generic_event::wait() |
224 | { |
225 | boost::unique_lock< boost::mutex > lock(m_mutex); |
226 | while (!m_state) |
227 | { |
228 | m_cond.wait(lock); |
229 | } |
230 | m_state = false; |
231 | } |
232 | |
233 | //! Sets the object to a signalled state |
234 | BOOST_LOG_API void generic_event::set_signalled() |
235 | { |
236 | boost::lock_guard< boost::mutex > lock(m_mutex); |
237 | if (!m_state) |
238 | { |
239 | m_state = true; |
240 | m_cond.notify_one(); |
241 | } |
242 | } |
243 | |
244 | #endif |
245 | |
246 | } // namespace aux |
247 | |
248 | BOOST_LOG_CLOSE_NAMESPACE // namespace log |
249 | |
250 | } // namespace boost |
251 | |
252 | #include <boost/log/detail/footer.hpp> |
253 | |
254 | #endif // BOOST_LOG_NO_THREADS |
255 | |