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>
42 enum class task_priority
54 executor(const executor&);
55 executor& operator=(const executor&);
57 typedef blocking_priority_queue<std::function<void()>, task_priority> function_queue_t;
59 const std::wstring name_;
60 tbb::atomic<bool> is_running_;
61 boost::thread thread_;
62 function_queue_t execution_queue_;
63 tbb::atomic<bool> currently_in_task_;
66 executor(const std::wstring& name)
68 , execution_queue_(512, std::vector<task_priority> {
69 task_priority::lowest_priority,
70 task_priority::lower_priority,
71 task_priority::low_priority,
72 task_priority::normal_priority,
73 task_priority::high_priority,
74 task_priority::higher_priority
78 currently_in_task_ = false;
79 thread_ = boost::thread([this]{run();});
84 CASPAR_LOG(debug) << L"Shutting down " << name_;
89 internal_begin_invoke([=]
96 CASPAR_LOG_CURRENT_EXCEPTION();
107 template<typename Func>
108 auto begin_invoke(Func&& func, task_priority priority = task_priority::normal_priority) -> std::future<decltype(func())> // noexcept
111 CASPAR_THROW_EXCEPTION(invalid_operation() << msg_info("executor not running.") << source_info(name_));
113 return internal_begin_invoke(std::forward<Func>(func), priority);
116 template<typename Func>
117 auto invoke(Func&& func, task_priority prioriy = task_priority::normal_priority) -> decltype(func()) // noexcept
119 if(is_current()) // Avoids potential deadlock.
122 return begin_invoke(std::forward<Func>(func), prioriy).get();
125 void yield(task_priority minimum_priority)
128 CASPAR_THROW_EXCEPTION(invalid_operation() << msg_info("Executor can only yield inside of thread context.") << source_info(name_));
130 std::function<void ()> func;
132 while (execution_queue_.try_pop(func, minimum_priority))
136 void set_capacity(function_queue_t::size_type capacity)
138 execution_queue_.set_capacity(capacity);
141 function_queue_t::size_type capacity() const
143 return execution_queue_.capacity();
148 return execution_queue_.space_available() == 0;
153 std::function<void ()> func;
154 while(execution_queue_.try_pop(func));
167 invoke([]{}, task_priority::lowest_priority);
170 function_queue_t::size_type size() const
172 return execution_queue_.size();
175 bool is_running() const
180 bool is_current() const
182 return boost::this_thread::get_id() == thread_.get_id();
185 bool is_currently_in_task() const
187 return currently_in_task_;
190 std::wstring name() const
197 std::wstring print() const
199 return L"executor[" + name_ + L"]";
202 template<typename Func>
203 auto internal_begin_invoke(
205 task_priority priority = task_priority::normal_priority) -> std::future<decltype(func())> // noexcept
207 typedef typename std::remove_reference<Func>::type function_type;
208 typedef decltype(func()) result_type;
209 typedef std::packaged_task<result_type()> task_type;
211 std::shared_ptr<task_type> task;
213 // Use pointers since the boost thread library doesn't fully support move semantics.
215 auto raw_func2 = new function_type(std::forward<Func>(func));
218 task.reset(new task_type([raw_func2]() -> result_type
220 std::unique_ptr<function_type> func2(raw_func2);
230 auto future = task->get_future().share();
231 auto function = [task]
237 catch(std::future_error&){}
240 if (!execution_queue_.try_push(priority, function))
242 CASPAR_LOG(warning) << print() << L" Overflow. Blocking caller.";
243 execution_queue_.push(priority, function);
246 return std::async(std::launch::deferred, [=]() mutable -> result_type
248 if (!is_ready(future) && is_current()) // Avoids potential deadlock.
257 catch (const caspar_exception& e)
259 if (!is_current()) // Add context information from this thread before rethrowing.
260 e << context_info(get_context() + *boost::get_error_info<context_info_t>(e));
267 void run() // noexcept
269 ensure_gpf_handler_installed_for_thread(u8(name_).c_str());
274 std::function<void ()> func;
275 execution_queue_.pop(func);
276 currently_in_task_ = true;
281 CASPAR_LOG_CURRENT_EXCEPTION();
284 currently_in_task_ = false;