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 "../exception/exceptions.h"\r
  26 #include "../utility/string.h"\r
  27 #include "../utility/move_on_copy.h"\r
  28 #include "../log/log.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 enum task_priority\r
  70 {\r
  71         high_priority,\r
  72         normal_priority,\r
  73         priority_count\r
  74 };\r
  75 \r
  76 enum thread_priority\r
  77 {\r
  78         high_priority_class,\r
  79         above_normal_priority_class,\r
  80         normal_priority_class,\r
  81         below_normal_priority_class\r
  82 };\r
  83 \r
  84 class executor : boost::noncopyable\r
  85 {\r
  86         const std::string name_;\r
  87         boost::thread thread_;\r
  88         tbb::atomic<bool> is_running_;\r
  89         \r
  90         typedef tbb::concurrent_bounded_queue<std::function<void()>> function_queue;\r
  91         function_queue execution_queue_[priority_count];\r
  92                 \r
  93         template<typename Func>\r
  94         auto create_task(Func&& func) -> boost::packaged_task<decltype(func())> // noexcept\r
  95         {       \r
  96                 typedef boost::packaged_task<decltype(func())> task_type;\r
  97                                 \r
  98                 auto task = task_type(std::forward<Func>(func));\r
  99                 \r
 100                 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
 101                 {\r
 102                         try\r
 103                         {\r
 104                                 if(boost::this_thread::get_id() == thread_.get_id())  // Avoids potential deadlock.\r
 105                                         my_task();\r
 106                         }\r
 107                         catch(boost::task_already_started&){}\r
 108                 }));\r
 109                                 \r
 110                 return std::move(task);\r
 111         }\r
 112 \r
 113 public:\r
 114                 \r
 115         explicit executor(const std::wstring& name) : name_(narrow(name)) // noexcept\r
 116         {\r
 117                 is_running_ = true;\r
 118                 thread_ = boost::thread([this]{run();});\r
 119         }\r
 120         \r
 121         virtual ~executor() // noexcept\r
 122         {\r
 123                 stop();\r
 124                 join();\r
 125         }\r
 126 \r
 127         void set_capacity(size_t capacity) // noexcept\r
 128         {\r
 129                 execution_queue_[normal_priority].set_capacity(capacity);\r
 130         }\r
 131 \r
 132         void set_priority_class(thread_priority p)\r
 133         {\r
 134                 begin_invoke([=]\r
 135                 {\r
 136                         if(p == high_priority_class)\r
 137                                 SetThreadPriority(GetCurrentThread(), HIGH_PRIORITY_CLASS);\r
 138                         else if(p == above_normal_priority_class)\r
 139                                 SetThreadPriority(GetCurrentThread(), ABOVE_NORMAL_PRIORITY_CLASS);\r
 140                         else if(p == normal_priority_class)\r
 141                                 SetThreadPriority(GetCurrentThread(), NORMAL_PRIORITY_CLASS);\r
 142                         else if(p == below_normal_priority_class)\r
 143                                 SetThreadPriority(GetCurrentThread(), BELOW_NORMAL_PRIORITY_CLASS);\r
 144                 });\r
 145         }\r
 146                                 \r
 147         void stop() // noexcept\r
 148         {\r
 149                 is_running_ = false;    \r
 150                 execution_queue_[normal_priority].try_push([]{}); // Wake the execution thread.\r
 151         }\r
 152 \r
 153         void wait() // noexcept\r
 154         {\r
 155                 invoke([]{});\r
 156         }\r
 157 \r
 158         void join()\r
 159         {\r
 160                 if(boost::this_thread::get_id() != thread_.get_id())\r
 161                         thread_.join();\r
 162         }\r
 163                                 \r
 164         template<typename Func>\r
 165         auto begin_invoke(Func&& func, task_priority priority = normal_priority) -> boost::unique_future<decltype(func())> // noexcept\r
 166         {       \r
 167                 if(!is_running_)\r
 168                         BOOST_THROW_EXCEPTION(invalid_operation() << msg_info("executor not running."));\r
 169 \r
 170                 // Create a move on copy adaptor to avoid copying the functor into the queue, tbb::concurrent_queue does not support move semantics.\r
 171                 auto task_adaptor = make_move_on_copy(create_task(func));\r
 172 \r
 173                 auto future = task_adaptor.value.get_future();\r
 174 \r
 175                 execution_queue_[priority].push([=]\r
 176                 {\r
 177                         try\r
 178                         {\r
 179                                 task_adaptor.value();\r
 180                         }\r
 181                         catch(boost::task_already_started&)\r
 182                         {\r
 183                         }\r
 184                         catch(...)\r
 185                         {\r
 186                                 CASPAR_LOG_CURRENT_EXCEPTION();\r
 187                         }\r
 188                 });\r
 189 \r
 190                 if(priority != normal_priority)\r
 191                         execution_queue_[normal_priority].push(nullptr);\r
 192                                         \r
 193                 return std::move(future);               \r
 194         }\r
 195         \r
 196         template<typename Func>\r
 197         auto invoke(Func&& func, task_priority prioriy = normal_priority) -> decltype(func()) // noexcept\r
 198         {\r
 199                 if(boost::this_thread::get_id() == thread_.get_id())  // Avoids potential deadlock.\r
 200                         return func();\r
 201                 \r
 202                 return begin_invoke(std::forward<Func>(func), prioriy).get();\r
 203         }\r
 204         \r
 205         void yield() // noexcept\r
 206         {\r
 207                 if(boost::this_thread::get_id() != thread_.get_id())  // Only yield when calling from execution thread.\r
 208                         return;\r
 209 \r
 210                 std::function<void()> func;\r
 211                 while(execution_queue_[high_priority].try_pop(func))\r
 212                 {\r
 213                         if(func)\r
 214                                 func();\r
 215                 }       \r
 216         }\r
 217         \r
 218         function_queue::size_type capacity() const /*noexcept*/ { return execution_queue_[normal_priority].capacity();  }\r
 219         function_queue::size_type size() const /*noexcept*/ { return execution_queue_[normal_priority].size();  }\r
 220         bool empty() const /*noexcept*/ { return execution_queue_[normal_priority].empty();     }\r
 221         bool is_running() const /*noexcept*/ { return is_running_; }    \r
 222                 \r
 223 private:\r
 224         \r
 225         void execute() // noexcept\r
 226         {\r
 227                 std::function<void()> func;\r
 228                 execution_queue_[normal_priority].pop(func);    \r
 229 \r
 230                 yield();\r
 231 \r
 232                 if(func)\r
 233                         func();\r
 234         }\r
 235 \r
 236         void run() // noexcept\r
 237         {\r
 238                 win32_exception::install_handler();             \r
 239                 detail::SetThreadName(GetCurrentThreadId(), name_.c_str());\r
 240                 while(is_running_)\r
 241                 {\r
 242                         try\r
 243                         {\r
 244                                 execute();\r
 245                         }\r
 246                         catch(...)\r
 247                         {\r
 248                                 CASPAR_LOG_CURRENT_EXCEPTION();\r
 249                         }\r
 250                 }\r
 251         }       \r
 252 };\r
 253 \r
 254 }