2 * Copyright (c) 2011 Sveriges Television AB <info@casparcg.com>
4 * This file is part of CasparCG (www.casparcg.com).
6 * CasparCG is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, either version 3 of the License, or
9 * (at your option) any later version.
11 * CasparCG is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with CasparCG. If not, see <http://www.gnu.org/licenses/>.
19 * Author: Robert Nagy, ronag89@gmail.com
24 #include "os/general_protection_fault.h"
27 #include "blocking_bounded_queue_adapter.h"
28 #include "blocking_priority_queue.h"
31 #include <tbb/atomic.h>
32 #include <tbb/concurrent_priority_queue.h>
34 #include <boost/thread.hpp>
35 #include <boost/optional.hpp>
41 enum class task_priority
53 executor(const executor&);
54 executor& operator=(const executor&);
56 typedef blocking_priority_queue<std::function<void()>, task_priority> function_queue_t;
58 const std::wstring name_;
59 tbb::atomic<bool> is_running_;
60 boost::thread thread_;
61 function_queue_t execution_queue_;
62 tbb::atomic<bool> currently_in_task_;
65 executor(const std::wstring& name)
67 , execution_queue_(std::numeric_limits<int>::max(), std::vector<task_priority> {
68 task_priority::lowest_priority,
69 task_priority::lower_priority,
70 task_priority::low_priority,
71 task_priority::normal_priority,
72 task_priority::high_priority,
73 task_priority::higher_priority
77 currently_in_task_ = false;
78 thread_ = boost::thread([this]{run();});
83 CASPAR_LOG(debug) << L"Shutting down " << name_;
88 internal_begin_invoke([=]
95 CASPAR_LOG_CURRENT_EXCEPTION();
106 template<typename Func>
107 auto begin_invoke(Func&& func, task_priority priority = task_priority::normal_priority) -> std::future<decltype(func())> // noexcept
110 CASPAR_THROW_EXCEPTION(invalid_operation() << msg_info("executor not running.") << source_info(name_));
112 return internal_begin_invoke(std::forward<Func>(func), priority);
115 template<typename Func>
116 auto invoke(Func&& func, task_priority prioriy = task_priority::normal_priority) -> decltype(func()) // noexcept
118 if(is_current()) // Avoids potential deadlock.
121 return begin_invoke(std::forward<Func>(func), prioriy).get();
124 void yield(task_priority minimum_priority)
127 CASPAR_THROW_EXCEPTION(invalid_operation() << msg_info("Executor can only yield inside of thread context.") << source_info(name_));
129 std::function<void ()> func;
131 while (execution_queue_.try_pop(func, minimum_priority))
135 void set_capacity(function_queue_t::size_type capacity)
137 execution_queue_.set_capacity(capacity);
140 function_queue_t::size_type capacity() const
142 return execution_queue_.capacity();
147 return execution_queue_.space_available() == 0;
152 std::function<void ()> func;
153 while(execution_queue_.try_pop(func));
166 invoke([]{}, task_priority::lowest_priority);
169 function_queue_t::size_type size() const
171 return execution_queue_.size();
174 bool is_running() const
179 bool is_current() const
181 return boost::this_thread::get_id() == thread_.get_id();
184 bool is_currently_in_task() const
186 return currently_in_task_;
189 std::wstring name() const
196 std::wstring print() const
198 return L"executor[" + name_ + L"]";
201 template<typename Func>
202 auto internal_begin_invoke(
204 task_priority priority = task_priority::normal_priority) -> std::future<decltype(func())> // noexcept
206 typedef typename std::remove_reference<Func>::type function_type;
207 typedef decltype(func()) result_type;
208 typedef std::packaged_task<result_type()> task_type;
210 std::shared_ptr<task_type> task;
212 // Use pointers since the boost thread library doesn't fully support move semantics.
214 auto raw_func2 = new function_type(std::forward<Func>(func));
217 task.reset(new task_type([raw_func2]() -> result_type
219 std::unique_ptr<function_type> func2(raw_func2);
229 auto future = task->get_future().share();
230 auto function = [task]
236 catch(std::future_error&){}
239 if (!execution_queue_.try_push(priority, function))
242 CASPAR_THROW_EXCEPTION(invalid_operation() << msg_info(print() + L" Overflow. Avoiding deadlock."));
244 CASPAR_LOG(warning) << print() << L" Overflow. Blocking caller.";
245 execution_queue_.push(priority, function);
248 return std::async(std::launch::deferred, [=]() mutable -> result_type
250 if (!is_ready(future) && is_current()) // Avoids potential deadlock.
259 catch (const caspar_exception& e)
261 if (!is_current()) // Add context information from this thread before rethrowing.
263 auto ctx_info = boost::get_error_info<context_info_t>(e);
266 e << context_info(get_context() + *ctx_info);
268 e << context_info(get_context());
276 void run() // noexcept
278 ensure_gpf_handler_installed_for_thread(u8(name_).c_str());
283 std::function<void ()> func;
284 execution_queue_.pop(func);
285 currently_in_task_ = true;
290 CASPAR_LOG_CURRENT_EXCEPTION();
293 currently_in_task_ = false;
299 std::function<void()> func;
301 while (execution_queue_.try_pop(func))
308 CASPAR_LOG_CURRENT_EXCEPTION();