// // detail/task_io_service.hpp // ~~~~~~~~~~~~~~~~~~~~~~~~~~ // // Copyright (c) 2003-2011 Christopher M. Kohlhoff (chris at kohlhoff dot com) // // Distributed under the Boost Software License, Version 1.0. (See accompanying // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) // #ifndef BOOST_ASIO_DETAIL_TASK_IO_SERVICE_HPP #define BOOST_ASIO_DETAIL_TASK_IO_SERVICE_HPP #if defined(_MSC_VER) && (_MSC_VER >= 1200) # pragma once #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) #include <boost/asio/detail/config.hpp> #if !defined(BOOST_ASIO_HAS_IOCP) #include <boost/detail/atomic_count.hpp> #include <boost/system/error_code.hpp> #include <boost/asio/io_service.hpp> #include <boost/asio/detail/mutex.hpp> #include <boost/asio/detail/op_queue.hpp> #include <boost/asio/detail/reactor_fwd.hpp> #include <boost/asio/detail/task_io_service_fwd.hpp> #include <boost/asio/detail/task_io_service_operation.hpp> #include <boost/asio/detail/push_options.hpp> namespace boost { namespace asio { namespace detail { class task_io_service : public boost::asio::detail::service_base<task_io_service> { public: typedef task_io_service_operation operation; // Constructor. BOOST_ASIO_DECL task_io_service(boost::asio::io_service& io_service); // How many concurrent threads are likely to run the io_service. BOOST_ASIO_DECL void init(std::size_t concurrency_hint); // Destroy all user-defined handler objects owned by the service. BOOST_ASIO_DECL void shutdown_service(); // Initialise the task, if required. BOOST_ASIO_DECL void init_task(); // Run the event loop until interrupted or no more work. BOOST_ASIO_DECL std::size_t run(boost::system::error_code& ec); // Run until interrupted or one operation is performed. BOOST_ASIO_DECL std::size_t run_one(boost::system::error_code& ec); // Poll for operations without blocking. BOOST_ASIO_DECL std::size_t poll(boost::system::error_code& ec); // Poll for one operation without blocking. BOOST_ASIO_DECL std::size_t poll_one(boost::system::error_code& ec); // Interrupt the event processing loop. BOOST_ASIO_DECL void stop(); // Reset in preparation for a subsequent run invocation. BOOST_ASIO_DECL void reset(); // Notify that some work has started. void work_started() { ++outstanding_work_; } // Notify that some work has finished. void work_finished() { if (--outstanding_work_ == 0) stop(); } // Request invocation of the given handler. template <typename Handler> void dispatch(Handler handler); // Request invocation of the given handler and return immediately. template <typename Handler> void post(Handler handler); // Request invocation of the given operation and return immediately. Assumes // that work_started() has not yet been called for the operation. BOOST_ASIO_DECL void post_immediate_completion(operation* op); // Request invocation of the given operation and return immediately. Assumes // that work_started() was previously called for the operation. BOOST_ASIO_DECL void post_deferred_completion(operation* op); // Request invocation of the given operations and return immediately. Assumes // that work_started() was previously called for each operation. BOOST_ASIO_DECL void post_deferred_completions(op_queue<operation>& ops); private: // Structure containing information about an idle thread. struct idle_thread_info; // Run at most one operation. Blocks only if this_idle_thread is non-null. BOOST_ASIO_DECL std::size_t do_one(mutex::scoped_lock& lock, idle_thread_info* this_idle_thread); // Stop the task and all idle threads. BOOST_ASIO_DECL void stop_all_threads(mutex::scoped_lock& lock); // Wakes a single idle thread and unlocks the mutex. Returns true if an idle // thread was found. If there is no idle thread, returns false and leaves the // mutex locked. BOOST_ASIO_DECL bool wake_one_idle_thread_and_unlock( mutex::scoped_lock& lock); // Wake a single idle thread, or the task, and always unlock the mutex. BOOST_ASIO_DECL void wake_one_thread_and_unlock( mutex::scoped_lock& lock); // Helper class to perform task-related operations on block exit. struct task_cleanup; friend struct task_cleanup; // Helper class to call work_finished() on block exit. struct work_finished_on_block_exit; // Mutex to protect access to internal data. mutex mutex_; // The task to be run by this service. reactor* task_; // Operation object to represent the position of the task in the queue. struct task_operation : operation { task_operation() : operation(0) {} } task_operation_; // Whether the task has been interrupted. bool task_interrupted_; // The count of unfinished work. boost::detail::atomic_count outstanding_work_; // The queue of handlers that are ready to be delivered. op_queue<operation> op_queue_; // Flag to indicate that the dispatcher has been stopped. bool stopped_; // Flag to indicate that the dispatcher has been shut down. bool shutdown_; // The threads that are currently idle. idle_thread_info* first_idle_thread_; }; } // namespace detail } // namespace asio } // namespace boost #include <boost/asio/detail/pop_options.hpp> #include <boost/asio/detail/impl/task_io_service.hpp> #if defined(BOOST_ASIO_HEADER_ONLY) # include <boost/asio/detail/impl/task_io_service.ipp> #endif // defined(BOOST_ASIO_HEADER_ONLY) #endif // !defined(BOOST_ASIO_HAS_IOCP) #endif // BOOST_ASIO_DETAIL_TASK_IO_SERVICE_HPP