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| author | manuel <manuel@mausz.at> | 2020-10-19 00:52:24 +0200 |
|---|---|---|
| committer | manuel <manuel@mausz.at> | 2020-10-19 00:52:24 +0200 |
| commit | be933ef2241d79558f91796cc5b3a161f72ebf9c (patch) | |
| tree | fe3ab2f130e20c99001f2d7a81d610c78c96a3f4 /xbmc/addons/kodi-dev-kit/include/kodi/tools/Thread.h | |
| parent | 5f8335c1e49ce108ef3481863833c98efa00411b (diff) | |
| download | kodi-pvr-build-be933ef2241d79558f91796cc5b3a161f72ebf9c.tar.gz kodi-pvr-build-be933ef2241d79558f91796cc5b3a161f72ebf9c.tar.bz2 kodi-pvr-build-be933ef2241d79558f91796cc5b3a161f72ebf9c.zip | |
sync with upstream
Diffstat (limited to 'xbmc/addons/kodi-dev-kit/include/kodi/tools/Thread.h')
| -rw-r--r-- | xbmc/addons/kodi-dev-kit/include/kodi/tools/Thread.h | 399 |
1 files changed, 399 insertions, 0 deletions
diff --git a/xbmc/addons/kodi-dev-kit/include/kodi/tools/Thread.h b/xbmc/addons/kodi-dev-kit/include/kodi/tools/Thread.h new file mode 100644 index 0000000..4cae13e --- /dev/null +++ b/xbmc/addons/kodi-dev-kit/include/kodi/tools/Thread.h | |||
| @@ -0,0 +1,399 @@ | |||
| 1 | /* | ||
| 2 | * Copyright (C) 2005-2020 Team Kodi | ||
| 3 | * This file is part of Kodi - https://kodi.tv | ||
| 4 | * | ||
| 5 | * SPDX-License-Identifier: GPL-2.0-or-later | ||
| 6 | * See LICENSES/README.md for more information. | ||
| 7 | */ | ||
| 8 | |||
| 9 | #pragma once | ||
| 10 | |||
| 11 | #ifdef __cplusplus | ||
| 12 | |||
| 13 | #include "../General.h" | ||
| 14 | |||
| 15 | #include <chrono> | ||
| 16 | #include <condition_variable> | ||
| 17 | #include <future> | ||
| 18 | #include <mutex> | ||
| 19 | #include <thread> | ||
| 20 | |||
| 21 | namespace kodi | ||
| 22 | { | ||
| 23 | namespace tools | ||
| 24 | { | ||
| 25 | |||
| 26 | //============================================================================== | ||
| 27 | /// @defgroup cpp_kodi_tools_CThread class CThread | ||
| 28 | /// @ingroup cpp_kodi_tools | ||
| 29 | /// @brief **Helper class to represent threads of execution**\n | ||
| 30 | /// An execution thread is a sequence of instructions that can run concurrently | ||
| 31 | /// with other such sequences in multithreaded environments while sharing the | ||
| 32 | /// same address space. | ||
| 33 | /// | ||
| 34 | /// Is intended to reduce any code work of C++ on addons and to have them faster | ||
| 35 | /// to use. | ||
| 36 | /// | ||
| 37 | /// His code uses the support of platform-independent thread system introduced | ||
| 38 | /// with C++11. | ||
| 39 | /// | ||
| 40 | /// ---------------------------------------------------------------------------- | ||
| 41 | /// | ||
| 42 | /// **Example:** | ||
| 43 | /// ~~~~~~~~~~~~~{.cpp} | ||
| 44 | /// #include <kodi/tools/Thread.h> | ||
| 45 | /// #include <kodi/AddonBase.h> | ||
| 46 | /// | ||
| 47 | /// class ATTRIBUTE_HIDDEN CTestAddon | ||
| 48 | /// : public kodi::addon::CAddonBase, | ||
| 49 | /// public kodi::tools::CThread | ||
| 50 | /// { | ||
| 51 | /// public: | ||
| 52 | /// CTestAddon() = default; | ||
| 53 | /// | ||
| 54 | /// ADDON_STATUS Create() override; | ||
| 55 | /// | ||
| 56 | /// void Process() override; | ||
| 57 | /// }; | ||
| 58 | /// | ||
| 59 | /// ADDON_STATUS CTestAddon::Create() | ||
| 60 | /// { | ||
| 61 | /// kodi::Log(ADDON_LOG_INFO, "Starting thread"); | ||
| 62 | /// CreateThread(); | ||
| 63 | /// | ||
| 64 | /// Sleep(4000); | ||
| 65 | /// | ||
| 66 | /// kodi::Log(ADDON_LOG_INFO, "Stopping thread"); | ||
| 67 | /// // This added as example and also becomes stopped by class destructor | ||
| 68 | /// StopThread(); | ||
| 69 | /// | ||
| 70 | /// return ADDON_STATUS_OK; | ||
| 71 | /// } | ||
| 72 | /// | ||
| 73 | /// void CTestAddon::Process() | ||
| 74 | /// { | ||
| 75 | /// kodi::Log(ADDON_LOG_INFO, "Thread started"); | ||
| 76 | /// | ||
| 77 | /// while (!m_threadStop) | ||
| 78 | /// { | ||
| 79 | /// kodi::Log(ADDON_LOG_INFO, "Hello World"); | ||
| 80 | /// Sleep(1000); | ||
| 81 | /// } | ||
| 82 | /// | ||
| 83 | /// kodi::Log(ADDON_LOG_INFO, "Thread ended"); | ||
| 84 | /// } | ||
| 85 | /// | ||
| 86 | /// ADDONCREATOR(CTestAddon) | ||
| 87 | /// ~~~~~~~~~~~~~ | ||
| 88 | /// | ||
| 89 | ///@{ | ||
| 90 | class CThread | ||
| 91 | { | ||
| 92 | public: | ||
| 93 | //============================================================================ | ||
| 94 | /// @ingroup cpp_kodi_tools_CThread | ||
| 95 | /// @brief Class constructor. | ||
| 96 | /// | ||
| 97 | CThread() : m_threadStop(false) {} | ||
| 98 | //---------------------------------------------------------------------------- | ||
| 99 | |||
| 100 | //============================================================================ | ||
| 101 | /// @ingroup cpp_kodi_tools_CThread | ||
| 102 | /// @brief Class destructor. | ||
| 103 | /// | ||
| 104 | virtual ~CThread() | ||
| 105 | { | ||
| 106 | StopThread(); | ||
| 107 | if (m_thread != nullptr) | ||
| 108 | { | ||
| 109 | m_thread->detach(); | ||
| 110 | delete m_thread; | ||
| 111 | } | ||
| 112 | } | ||
| 113 | //---------------------------------------------------------------------------- | ||
| 114 | |||
| 115 | //============================================================================ | ||
| 116 | /// @ingroup cpp_kodi_tools_CThread | ||
| 117 | /// @brief Check auto delete is enabled on this thread class. | ||
| 118 | /// | ||
| 119 | /// @return true if auto delete is used, false otherwise | ||
| 120 | /// | ||
| 121 | bool IsAutoDelete() const { return m_autoDelete; } | ||
| 122 | //---------------------------------------------------------------------------- | ||
| 123 | |||
| 124 | //============================================================================ | ||
| 125 | /// @ingroup cpp_kodi_tools_CThread | ||
| 126 | /// @brief Check caller is on this running thread. | ||
| 127 | /// | ||
| 128 | /// @return true if called from thread inside the class, false if from another | ||
| 129 | /// thread | ||
| 130 | /// | ||
| 131 | bool IsCurrentThread() const { return m_threadId == std::this_thread::get_id(); } | ||
| 132 | //---------------------------------------------------------------------------- | ||
| 133 | |||
| 134 | //============================================================================ | ||
| 135 | /// @ingroup cpp_kodi_tools_CThread | ||
| 136 | /// @brief Check thread inside this class is running and active. | ||
| 137 | /// | ||
| 138 | /// @note This function should be used from outside and not within process to | ||
| 139 | /// check thread is active. Use use atomic bool @ref m_threadStop for this. | ||
| 140 | /// | ||
| 141 | /// @return true if running, false if not | ||
| 142 | /// | ||
| 143 | bool IsRunning() const | ||
| 144 | { | ||
| 145 | if (m_thread != nullptr) | ||
| 146 | { | ||
| 147 | // it's possible that the thread exited on it's own without a call to StopThread. If so then | ||
| 148 | // the promise should be fulfilled. | ||
| 149 | std::future_status stat = m_future.wait_for(std::chrono::milliseconds(0)); | ||
| 150 | // a status of 'ready' means the future contains the value so the thread has exited | ||
| 151 | // since the thread can't exit without setting the future. | ||
| 152 | if (stat == std::future_status::ready) // this is an indication the thread has exited. | ||
| 153 | return false; | ||
| 154 | return true; // otherwise the thread is still active. | ||
| 155 | } | ||
| 156 | else | ||
| 157 | return false; | ||
| 158 | } | ||
| 159 | //---------------------------------------------------------------------------- | ||
| 160 | |||
| 161 | //============================================================================ | ||
| 162 | /// @ingroup cpp_kodi_tools_CThread | ||
| 163 | /// @brief Create a new thread defined by this class on child. | ||
| 164 | /// | ||
| 165 | /// This starts then @ref Process() where is available on the child by addon. | ||
| 166 | /// | ||
| 167 | /// @param[in] autoDelete To set thread to delete itself after end, default is | ||
| 168 | /// false | ||
| 169 | /// | ||
| 170 | void CreateThread(bool autoDelete = false) | ||
| 171 | { | ||
| 172 | if (m_thread != nullptr) | ||
| 173 | { | ||
| 174 | // if the thread exited on it's own, without a call to StopThread, then we can get here | ||
| 175 | // incorrectly. We should be able to determine this by checking the promise. | ||
| 176 | std::future_status stat = m_future.wait_for(std::chrono::milliseconds(0)); | ||
| 177 | // a status of 'ready' means the future contains the value so the thread has exited | ||
| 178 | // since the thread can't exit without setting the future. | ||
| 179 | if (stat == std::future_status::ready) // this is an indication the thread has exited. | ||
| 180 | StopThread(true); // so let's just clean up | ||
| 181 | else | ||
| 182 | { // otherwise we have a problem. | ||
| 183 | kodi::Log(ADDON_LOG_FATAL, "%s - fatal error creating thread - old thread id not null", | ||
| 184 | __func__); | ||
| 185 | exit(1); | ||
| 186 | } | ||
| 187 | } | ||
| 188 | |||
| 189 | m_autoDelete = autoDelete; | ||
| 190 | m_threadStop = false; | ||
| 191 | m_startEvent.notify_all(); | ||
| 192 | m_stopEvent.notify_all(); | ||
| 193 | |||
| 194 | std::promise<bool> prom; | ||
| 195 | m_future = prom.get_future(); | ||
| 196 | |||
| 197 | { | ||
| 198 | // The std::thread internals must be set prior to the lambda doing | ||
| 199 | // any work. This will cause the lambda to wait until m_thread | ||
| 200 | // is fully initialized. Interestingly, using a std::atomic doesn't | ||
| 201 | // have the appropriate memory barrier behavior to accomplish the | ||
| 202 | // same thing so a full system mutex needs to be used. | ||
| 203 | std::unique_lock<std::recursive_mutex> lock(m_threadMutex); | ||
| 204 | m_thread = new std::thread( | ||
| 205 | [](CThread* thread, std::promise<bool> promise) { | ||
| 206 | try | ||
| 207 | { | ||
| 208 | { | ||
| 209 | // Wait for the pThread->m_thread internals to be set. Otherwise we could | ||
| 210 | // get to a place where we're reading, say, the thread id inside this | ||
| 211 | // lambda's call stack prior to the thread that kicked off this lambda | ||
| 212 | // having it set. Once this lock is released, the CThread::Create function | ||
| 213 | // that kicked this off is done so everything should be set. | ||
| 214 | std::unique_lock<std::recursive_mutex> lock(thread->m_threadMutex); | ||
| 215 | } | ||
| 216 | |||
| 217 | thread->m_threadId = std::this_thread::get_id(); | ||
| 218 | std::stringstream ss; | ||
| 219 | ss << thread->m_threadId; | ||
| 220 | std::string id = ss.str(); | ||
| 221 | bool autodelete = thread->m_autoDelete; | ||
| 222 | |||
| 223 | kodi::Log(ADDON_LOG_DEBUG, "Thread %s start, auto delete: %s", id.c_str(), | ||
| 224 | (autodelete ? "true" : "false")); | ||
| 225 | |||
| 226 | thread->m_running = true; | ||
| 227 | thread->m_startEvent.notify_one(); | ||
| 228 | |||
| 229 | thread->Process(); | ||
| 230 | |||
| 231 | if (autodelete) | ||
| 232 | { | ||
| 233 | kodi::Log(ADDON_LOG_DEBUG, "Thread %s terminating (autodelete)", id.c_str()); | ||
| 234 | delete thread; | ||
| 235 | thread = nullptr; | ||
| 236 | } | ||
| 237 | else | ||
| 238 | kodi::Log(ADDON_LOG_DEBUG, "Thread %s terminating", id.c_str()); | ||
| 239 | } | ||
| 240 | catch (const std::exception& e) | ||
| 241 | { | ||
| 242 | kodi::Log(ADDON_LOG_DEBUG, "Thread Terminating with Exception: %s", e.what()); | ||
| 243 | } | ||
| 244 | catch (...) | ||
| 245 | { | ||
| 246 | kodi::Log(ADDON_LOG_DEBUG, "Thread Terminating with Exception"); | ||
| 247 | } | ||
| 248 | |||
| 249 | promise.set_value(true); | ||
| 250 | }, | ||
| 251 | this, std::move(prom)); | ||
| 252 | |||
| 253 | m_startEvent.wait(lock); | ||
| 254 | } | ||
| 255 | } | ||
| 256 | //---------------------------------------------------------------------------- | ||
| 257 | |||
| 258 | //============================================================================ | ||
| 259 | /// @ingroup cpp_kodi_tools_CThread | ||
| 260 | /// @brief Stop a running thread. | ||
| 261 | /// | ||
| 262 | /// @param[in] wait As true (default) to wait until thread is finished and | ||
| 263 | /// stopped, as false the function return directly and thread | ||
| 264 | /// becomes independently stopped. | ||
| 265 | /// | ||
| 266 | void StopThread(bool wait = true) | ||
| 267 | { | ||
| 268 | std::unique_lock<std::recursive_mutex> lock(m_threadMutex); | ||
| 269 | |||
| 270 | if (m_threadStop) | ||
| 271 | return; | ||
| 272 | |||
| 273 | if (m_thread && !m_running) | ||
| 274 | m_startEvent.wait(lock); | ||
| 275 | m_running = false; | ||
| 276 | m_threadStop = true; | ||
| 277 | m_stopEvent.notify_one(); | ||
| 278 | |||
| 279 | std::thread* lthread = m_thread; | ||
| 280 | if (lthread != nullptr && wait && !IsCurrentThread()) | ||
| 281 | { | ||
| 282 | lock.unlock(); | ||
| 283 | if (lthread->joinable()) | ||
| 284 | lthread->join(); | ||
| 285 | delete m_thread; | ||
| 286 | m_thread = nullptr; | ||
| 287 | m_threadId = std::thread::id(); | ||
| 288 | } | ||
| 289 | } | ||
| 290 | //---------------------------------------------------------------------------- | ||
| 291 | |||
| 292 | //============================================================================ | ||
| 293 | /// @ingroup cpp_kodi_tools_CThread | ||
| 294 | /// @brief Thread sleep with given amount of milliseconds. | ||
| 295 | /// | ||
| 296 | /// This makes a sleep in the thread with a given time value. If it is called | ||
| 297 | /// within the process itself, it is also checked whether the thread is | ||
| 298 | /// terminated and the sleep process is thereby interrupted. | ||
| 299 | /// | ||
| 300 | /// If the external point calls this, only a regular sleep is used, which runs | ||
| 301 | /// through completely. | ||
| 302 | /// | ||
| 303 | /// @param[in] milliseconds Time to sleep | ||
| 304 | /// | ||
| 305 | void Sleep(uint32_t milliseconds) | ||
| 306 | { | ||
| 307 | if (milliseconds > 10 && IsCurrentThread()) | ||
| 308 | { | ||
| 309 | std::unique_lock<std::recursive_mutex> lock(m_threadMutex); | ||
| 310 | m_stopEvent.wait_for(lock, std::chrono::milliseconds(milliseconds)); | ||
| 311 | } | ||
| 312 | else | ||
| 313 | { | ||
| 314 | std::this_thread::sleep_for(std::chrono::milliseconds(milliseconds)); | ||
| 315 | } | ||
| 316 | } | ||
| 317 | //---------------------------------------------------------------------------- | ||
| 318 | |||
| 319 | //============================================================================ | ||
| 320 | /// @ingroup cpp_kodi_tools_CThread | ||
| 321 | /// @brief The function returns when the thread execution has completed or | ||
| 322 | /// timing is reached in milliseconds beforehand | ||
| 323 | /// | ||
| 324 | /// This synchronizes the moment this function returns with the completion of | ||
| 325 | /// all operations on the thread. | ||
| 326 | /// | ||
| 327 | /// @param[in] milliseconds Time to wait for join | ||
| 328 | /// | ||
| 329 | bool Join(unsigned int milliseconds) | ||
| 330 | { | ||
| 331 | std::unique_lock<std::recursive_mutex> lock(m_threadMutex); | ||
| 332 | std::thread* lthread = m_thread; | ||
| 333 | if (lthread != nullptr) | ||
| 334 | { | ||
| 335 | if (IsCurrentThread()) | ||
| 336 | return false; | ||
| 337 | |||
| 338 | { | ||
| 339 | m_threadMutex.unlock(); // don't hold the thread lock while we're waiting | ||
| 340 | std::future_status stat = m_future.wait_for(std::chrono::milliseconds(milliseconds)); | ||
| 341 | if (stat != std::future_status::ready) | ||
| 342 | return false; | ||
| 343 | m_threadMutex.lock(); | ||
| 344 | } | ||
| 345 | |||
| 346 | // it's possible it's already joined since we released the lock above. | ||
| 347 | if (lthread->joinable()) | ||
| 348 | m_thread->join(); | ||
| 349 | return true; | ||
| 350 | } | ||
| 351 | else | ||
| 352 | return false; | ||
| 353 | } | ||
| 354 | //---------------------------------------------------------------------------- | ||
| 355 | |||
| 356 | protected: | ||
| 357 | //============================================================================ | ||
| 358 | /// @ingroup cpp_kodi_tools_CThread | ||
| 359 | /// @brief The function to be added by the addon as a child to carry out the | ||
| 360 | /// process thread. | ||
| 361 | /// | ||
| 362 | /// Use @ref m_threadStop to check about active of thread and want stopped from | ||
| 363 | /// external place. | ||
| 364 | /// | ||
| 365 | /// @note This function is necessary and must be implemented by the addon. | ||
| 366 | /// | ||
| 367 | virtual void Process() = 0; | ||
| 368 | //---------------------------------------------------------------------------- | ||
| 369 | |||
| 370 | //============================================================================ | ||
| 371 | /// @ingroup cpp_kodi_tools_CThread | ||
| 372 | /// @brief Atomic bool to indicate thread is active. | ||
| 373 | /// | ||
| 374 | /// This should be used in @ref Process() to check the activity of the thread and, | ||
| 375 | /// if true, to terminate the process. | ||
| 376 | /// | ||
| 377 | /// - <b>`false`</b>: Thread active and should be run | ||
| 378 | /// - <b>`true`</b>: Thread ends and should be stopped | ||
| 379 | /// | ||
| 380 | std::atomic<bool> m_threadStop; | ||
| 381 | //---------------------------------------------------------------------------- | ||
| 382 | |||
| 383 | private: | ||
| 384 | bool m_autoDelete = false; | ||
| 385 | bool m_running = false; | ||
| 386 | std::condition_variable_any m_stopEvent; | ||
| 387 | std::condition_variable_any m_startEvent; | ||
| 388 | std::recursive_mutex m_threadMutex; | ||
| 389 | std::thread::id m_threadId; | ||
| 390 | std::thread* m_thread = nullptr; | ||
| 391 | std::future<bool> m_future; | ||
| 392 | }; | ||
| 393 | ///@} | ||
| 394 | //------------------------------------------------------------------------------ | ||
| 395 | |||
| 396 | } /* namespace tools */ | ||
| 397 | } /* namespace kodi */ | ||
| 398 | |||
| 399 | #endif /* __cplusplus */ | ||
