32 #include <condition_variable>
41 template<
class F,
class... Args>
42 auto enqueue(F&& f, Args&&... args)
43 -> std::future<
typename std::result_of<F(Args...)>::type>;
47 std::vector< std::thread > workers;
49 std::queue< std::function<void()> > tasks;
52 std::mutex queue_mutex;
53 std::condition_variable condition;
58 inline ThreadPool::ThreadPool(
size_t threads)
61 for(
size_t i = 0;i<threads;++i)
67 std::function<void()> task;
70 std::unique_lock<std::mutex> lock(this->queue_mutex);
71 this->condition.wait(lock,
72 [this]{ return this->stop || !this->tasks.empty(); });
73 if(this->stop && this->tasks.empty())
75 task = std::move(this->tasks.front());
86 template<
class F,
class... Args>
87 auto ThreadPool::enqueue(F&& f, Args&&... args)
88 -> std::future<
typename std::result_of<F(Args...)>::type>
90 using return_type =
typename std::result_of<F(Args...)>::type;
92 auto task = std::make_shared< std::packaged_task<return_type()> >(
93 std::bind(std::forward<F>(f), std::forward<Args>(args)...)
96 std::future<return_type> res = task->get_future();
98 std::unique_lock<std::mutex> lock(queue_mutex);
102 throw std::runtime_error(
"enqueue on stopped ThreadPool");
104 tasks.emplace([task](){ (*task)(); });
106 condition.notify_one();
111 inline ThreadPool::~ThreadPool()
114 std::unique_lock<std::mutex> lock(queue_mutex);
117 condition.notify_all();
118 for(std::thread &worker: workers)