git.sesse.net Git - casparcg/blob - common/concurrency/executor.h

   1 /*\r
   2 * Copyright (c) 2011 Sveriges Television AB <info@casparcg.com>\r
   3 *\r
   4 * This file is part of CasparCG (www.casparcg.com).\r
   5 *\r
   6 * CasparCG is free software: you can redistribute it and/or modify\r
   7 * it under the terms of the GNU General Public License as published by\r
   8 * the Free Software Foundation, either version 3 of the License, or\r
   9 * (at your option) any later version.\r
  10 *\r
  11 * CasparCG is distributed in the hope that it will be useful,\r
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of\r
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\r
  14 * GNU General Public License for more details.\r
  15 *\r
  16 * You should have received a copy of the GNU General Public License\r
  17 * along with CasparCG. If not, see <http://www.gnu.org/licenses/>.\r
  18 *\r
  19 * Author: Robert Nagy, ronag89@gmail.com\r
  20 */\r
  21 \r
  22 #pragma once\r
  23 \r
  24 #include "../exception/win32_exception.h"\r
  25 #include "../utility/move_on_copy.h"\r
  26 #include "../log.h"\r
  27 \r
  28 #include <Windows.h>\r
  29 \r
  30 #include <tbb/atomic.h>\r
  31 #include <tbb/concurrent_queue.h>\r
  32 \r
  33 #include <boost/thread.hpp>\r
  34 #include <boost/optional.hpp>\r
  35 #include <boost/noncopyable.hpp>\r
  36 \r
  37 #include <functional>\r
  38 \r
  39 namespace caspar {\r
  40 \r
  41 namespace detail {\r
  42 \r
  43 //typedef struct tagTHREADNAME_INFO\r
  44 //{\r
  45 //      DWORD dwType; // must be 0x1000\r
  46 //      LPCSTR szName; // pointer to name (in user addr space)\r
  47 //      DWORD dwThreadID; // thread ID (-1=caller thread)\r
  48 //      DWORD dwFlags; // reserved for future use, must be zero\r
  49 //} THREADNAME_INFO;\r
  50 //\r
  51 //inline void SetThreadName(DWORD dwThreadID, LPCSTR szThreadName)\r
  52 //{\r
  53 //      THREADNAME_INFO info;\r
  54 //      {\r
  55 //              info.dwType = 0x1000;\r
  56 //              info.szName = szThreadName;\r
  57 //              info.dwThreadID = dwThreadID;\r
  58 //              info.dwFlags = 0;\r
  59 //      }\r
  60 //      __try\r
  61 //      {\r
  62 //              RaiseException( 0x406D1388, 0, sizeof(info)/sizeof(DWORD), (DWORD*)&info );\r
  63 //      }\r
  64 //      __except (EXCEPTION_CONTINUE_EXECUTION){}       \r
  65 //}\r
  66 //\r
  67 //}\r
  68 }\r
  69 \r
  70 enum task_priority\r
  71 {\r
  72         high_priority,\r
  73         normal_priority,\r
  74         priority_count\r
  75 };\r
  76 \r
  77 enum thread_priority\r
  78 {\r
  79         high_priority_class,\r
  80         above_normal_priority_class,\r
  81         normal_priority_class,\r
  82         below_normal_priority_class\r
  83 };\r
  84 \r
  85 class executor : boost::noncopyable\r
  86 {\r
  87         const std::string name_;\r
  88         boost::thread thread_;\r
  89         tbb::atomic<bool> is_running_;\r
  90         \r
  91         typedef tbb::concurrent_bounded_queue<std::function<void()>> function_queue;\r
  92         function_queue execution_queue_[priority_count];\r
  93                 \r
  94         template<typename Func>\r
  95         auto create_task(Func&& func) -> boost::packaged_task<decltype(func())> // noexcept\r
  96         {       \r
  97                 typedef boost::packaged_task<decltype(func())> task_type;\r
  98                                 \r
  99                 auto task = task_type(std::forward<Func>(func));\r
 100                 \r
 101                 task.set_wait_callback(std::function<void(task_type&)>([=](task_type& my_task) // The std::function wrapper is required in order to add ::result_type to functor class.\r
 102                 {\r
 103                         try\r
 104                         {\r
 105                                 if(boost::this_thread::get_id() == thread_.get_id())  // Avoids potential deadlock.\r
 106                                         my_task();\r
 107                         }\r
 108                         catch(boost::task_already_started&){}\r
 109                 }));\r
 110                                 \r
 111                 return std::move(task);\r
 112         }\r
 113 \r
 114 public:\r
 115                 \r
 116         explicit executor(const std::wstring& name) : name_(u8(name)) // noexcept\r
 117         {\r
 118                 is_running_ = true;\r
 119                 thread_ = boost::thread([this]{run();});\r
 120         }\r
 121         \r
 122         virtual ~executor() // noexcept\r
 123         {\r
 124                 stop();\r
 125                 join();\r
 126         }\r
 127 \r
 128         void set_capacity(size_t capacity) // noexcept\r
 129         {\r
 130                 execution_queue_[normal_priority].set_capacity(capacity);\r
 131         }\r
 132 \r
 133         void set_priority_class(thread_priority p)\r
 134         {\r
 135                 begin_invoke([=]\r
 136                 {\r
 137                         if(p == high_priority_class)\r
 138                                 SetThreadPriority(GetCurrentThread(), HIGH_PRIORITY_CLASS);\r
 139                         else if(p == above_normal_priority_class)\r
 140                                 SetThreadPriority(GetCurrentThread(), ABOVE_NORMAL_PRIORITY_CLASS);\r
 141                         else if(p == normal_priority_class)\r
 142                                 SetThreadPriority(GetCurrentThread(), NORMAL_PRIORITY_CLASS);\r
 143                         else if(p == below_normal_priority_class)\r
 144                                 SetThreadPriority(GetCurrentThread(), BELOW_NORMAL_PRIORITY_CLASS);\r
 145                 });\r
 146         }\r
 147         \r
 148         void clear()\r
 149         {               \r
 150                 std::function<void()> func;\r
 151                 while(execution_queue_[normal_priority].try_pop(func));\r
 152                 while(execution_queue_[high_priority].try_pop(func));\r
 153         }\r
 154                                 \r
 155         void stop() // noexcept\r
 156         {\r
 157                 is_running_ = false;    \r
 158                 execution_queue_[normal_priority].try_push([]{}); // Wake the execution thread.\r
 159         }\r
 160 \r
 161         void wait() // noexcept\r
 162         {\r
 163                 invoke([]{});\r
 164         }\r
 165 \r
 166         void join()\r
 167         {\r
 168                 if(boost::this_thread::get_id() != thread_.get_id())\r
 169                         thread_.join();\r
 170         }\r
 171                                 \r
 172         template<typename Func>\r
 173         auto begin_invoke(Func&& func, task_priority priority = normal_priority) -> boost::unique_future<decltype(func())> // noexcept\r
 174         {       \r
 175                 if(!is_running_)\r
 176                         BOOST_THROW_EXCEPTION(invalid_operation() << msg_info("executor not running."));\r
 177 \r
 178                 // Create a move on copy adaptor to avoid copying the functor into the queue, tbb::concurrent_queue does not support move semantics.\r
 179                 auto task_adaptor = make_move_on_copy(create_task(func));\r
 180 \r
 181                 auto future = task_adaptor.value.get_future();\r
 182 \r
 183                 execution_queue_[priority].push([=]\r
 184                 {\r
 185                         try\r
 186                         {\r
 187                                 task_adaptor.value();\r
 188                         }\r
 189                         catch(boost::task_already_started&)\r
 190                         {\r
 191                         }\r
 192                         catch(...)\r
 193                         {\r
 194                                 CASPAR_LOG_CURRENT_EXCEPTION();\r
 195                         }\r
 196                 });\r
 197 \r
 198                 if(priority != normal_priority)\r
 199                         execution_queue_[normal_priority].push(nullptr);\r
 200                                         \r
 201                 return std::move(future);               \r
 202         }\r
 203         \r
 204         template<typename Func>\r
 205         auto invoke(Func&& func, task_priority prioriy = normal_priority) -> decltype(func()) // noexcept\r
 206         {\r
 207                 if(boost::this_thread::get_id() == thread_.get_id())  // Avoids potential deadlock.\r
 208                         return func();\r
 209                 \r
 210                 return begin_invoke(std::forward<Func>(func), prioriy).get();\r
 211         }\r
 212         \r
 213         void yield() // noexcept\r
 214         {\r
 215                 if(boost::this_thread::get_id() != thread_.get_id())  // Only yield when calling from execution thread.\r
 216                         return;\r
 217 \r
 218                 std::function<void()> func;\r
 219                 while(execution_queue_[high_priority].try_pop(func))\r
 220                 {\r
 221                         if(func)\r
 222                                 func();\r
 223                 }       \r
 224         }\r
 225         \r
 226         function_queue::size_type capacity() const /*noexcept*/ { return execution_queue_[normal_priority].capacity();  }\r
 227         function_queue::size_type size() const /*noexcept*/ { return execution_queue_[normal_priority].size();  }\r
 228         bool empty() const /*noexcept*/ { return execution_queue_[normal_priority].empty();     }\r
 229         bool is_running() const /*noexcept*/ { return is_running_; }    \r
 230                 \r
 231 private:\r
 232         \r
 233         void execute() // noexcept\r
 234         {\r
 235                 std::function<void()> func;\r
 236                 execution_queue_[normal_priority].pop(func);    \r
 237 \r
 238                 yield();\r
 239 \r
 240                 if(func)\r
 241                         func();\r
 242         }\r
 243 \r
 244         void run() // noexcept\r
 245         {\r
 246                 win32_exception::install_handler();             \r
 247                 //detail::SetThreadName(GetCurrentThreadId(), name_.c_str());\r
 248                 while(is_running_)\r
 249                 {\r
 250                         try\r
 251                         {\r
 252                                 execute();\r
 253                         }\r
 254                         catch(...)\r
 255                         {\r
 256                                 CASPAR_LOG_CURRENT_EXCEPTION();\r
 257                         }\r
 258                 }\r
 259         }       \r
 260 };\r
 261 \r
 262 }