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author | Remko Tronçon <git@el-tramo.be> | 2009-06-01 08:48:42 (GMT) |
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committer | Remko Tronçon <git@el-tramo.be> | 2009-06-01 09:24:28 (GMT) |
commit | 2812bddd81f8a1b804c7460f4e14cd0aa393d129 (patch) | |
tree | d46294f35150c4f0f43deaf2d31fceaf945ae715 /3rdParty/Boost/boost/asio/detail/select_reactor.hpp | |
download | swift-2812bddd81f8a1b804c7460f4e14cd0aa393d129.zip swift-2812bddd81f8a1b804c7460f4e14cd0aa393d129.tar.bz2 |
Import.
Diffstat (limited to '3rdParty/Boost/boost/asio/detail/select_reactor.hpp')
-rw-r--r-- | 3rdParty/Boost/boost/asio/detail/select_reactor.hpp | 546 |
1 files changed, 546 insertions, 0 deletions
diff --git a/3rdParty/Boost/boost/asio/detail/select_reactor.hpp b/3rdParty/Boost/boost/asio/detail/select_reactor.hpp new file mode 100644 index 0000000..77caf54 --- /dev/null +++ b/3rdParty/Boost/boost/asio/detail/select_reactor.hpp @@ -0,0 +1,546 @@ +// +// select_reactor.hpp +// ~~~~~~~~~~~~~~~~~~ +// +// Copyright (c) 2003-2008 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_SELECT_REACTOR_HPP +#define BOOST_ASIO_DETAIL_SELECT_REACTOR_HPP + +#if defined(_MSC_VER) && (_MSC_VER >= 1200) +# pragma once +#endif // defined(_MSC_VER) && (_MSC_VER >= 1200) + +#include <boost/asio/detail/push_options.hpp> + +#include <boost/asio/detail/socket_types.hpp> // Must come before posix_time. + +#include <boost/asio/detail/push_options.hpp> +#include <cstddef> +#include <boost/config.hpp> +#include <boost/date_time/posix_time/posix_time_types.hpp> +#include <boost/shared_ptr.hpp> +#include <vector> +#include <boost/asio/detail/pop_options.hpp> + +#include <boost/asio/io_service.hpp> +#include <boost/asio/detail/bind_handler.hpp> +#include <boost/asio/detail/fd_set_adapter.hpp> +#include <boost/asio/detail/mutex.hpp> +#include <boost/asio/detail/noncopyable.hpp> +#include <boost/asio/detail/reactor_op_queue.hpp> +#include <boost/asio/detail/select_interrupter.hpp> +#include <boost/asio/detail/select_reactor_fwd.hpp> +#include <boost/asio/detail/service_base.hpp> +#include <boost/asio/detail/signal_blocker.hpp> +#include <boost/asio/detail/socket_ops.hpp> +#include <boost/asio/detail/socket_types.hpp> +#include <boost/asio/detail/task_io_service.hpp> +#include <boost/asio/detail/thread.hpp> +#include <boost/asio/detail/timer_queue.hpp> + +namespace boost { +namespace asio { +namespace detail { + +template <bool Own_Thread> +class select_reactor + : public boost::asio::detail::service_base<select_reactor<Own_Thread> > +{ +public: + // Per-descriptor data. + struct per_descriptor_data + { + }; + + // Constructor. + select_reactor(boost::asio::io_service& io_service) + : boost::asio::detail::service_base< + select_reactor<Own_Thread> >(io_service), + mutex_(), + select_in_progress_(false), + interrupter_(), + read_op_queue_(), + write_op_queue_(), + except_op_queue_(), + pending_cancellations_(), + stop_thread_(false), + thread_(0), + shutdown_(false) + { + if (Own_Thread) + { + boost::asio::detail::signal_blocker sb; + thread_ = new boost::asio::detail::thread( + bind_handler(&select_reactor::call_run_thread, this)); + } + } + + // Destructor. + ~select_reactor() + { + shutdown_service(); + } + + // Destroy all user-defined handler objects owned by the service. + void shutdown_service() + { + boost::asio::detail::mutex::scoped_lock lock(mutex_); + shutdown_ = true; + stop_thread_ = true; + lock.unlock(); + + if (thread_) + { + interrupter_.interrupt(); + thread_->join(); + delete thread_; + thread_ = 0; + } + + read_op_queue_.destroy_operations(); + write_op_queue_.destroy_operations(); + except_op_queue_.destroy_operations(); + + for (std::size_t i = 0; i < timer_queues_.size(); ++i) + timer_queues_[i]->destroy_timers(); + timer_queues_.clear(); + } + + // Initialise the task, but only if the reactor is not in its own thread. + void init_task() + { + if (!Own_Thread) + { + typedef task_io_service<select_reactor<Own_Thread> > task_io_service_type; + use_service<task_io_service_type>(this->get_io_service()).init_task(); + } + } + + // Register a socket with the reactor. Returns 0 on success, system error + // code on failure. + int register_descriptor(socket_type, per_descriptor_data&) + { + return 0; + } + + // Start a new read operation. The handler object will be invoked when the + // given descriptor is ready to be read, or an error has occurred. + template <typename Handler> + void start_read_op(socket_type descriptor, per_descriptor_data&, + Handler handler, bool /*allow_speculative_read*/ = true) + { + boost::asio::detail::mutex::scoped_lock lock(mutex_); + if (!shutdown_) + if (read_op_queue_.enqueue_operation(descriptor, handler)) + interrupter_.interrupt(); + } + + // Start a new write operation. The handler object will be invoked when the + // given descriptor is ready to be written, or an error has occurred. + template <typename Handler> + void start_write_op(socket_type descriptor, per_descriptor_data&, + Handler handler, bool /*allow_speculative_write*/ = true) + { + boost::asio::detail::mutex::scoped_lock lock(mutex_); + if (!shutdown_) + if (write_op_queue_.enqueue_operation(descriptor, handler)) + interrupter_.interrupt(); + } + + // Start a new exception operation. The handler object will be invoked when + // the given descriptor has exception information, or an error has occurred. + template <typename Handler> + void start_except_op(socket_type descriptor, + per_descriptor_data&, Handler handler) + { + boost::asio::detail::mutex::scoped_lock lock(mutex_); + if (!shutdown_) + if (except_op_queue_.enqueue_operation(descriptor, handler)) + interrupter_.interrupt(); + } + + // Wrapper for connect handlers to enable the handler object to be placed + // in both the write and the except operation queues, but ensure that only + // one of the handlers is called. + template <typename Handler> + class connect_handler_wrapper + { + public: + connect_handler_wrapper(socket_type descriptor, + boost::shared_ptr<bool> completed, + select_reactor<Own_Thread>& reactor, Handler handler) + : descriptor_(descriptor), + completed_(completed), + reactor_(reactor), + handler_(handler) + { + } + + bool perform(boost::system::error_code& ec, + std::size_t& bytes_transferred) + { + // Check whether one of the handlers has already been called. If it has, + // then we don't want to do anything in this handler. + if (*completed_) + { + completed_.reset(); // Indicate that this handler should not complete. + return true; + } + + // Cancel the other reactor operation for the connection. + *completed_ = true; + reactor_.enqueue_cancel_ops_unlocked(descriptor_); + + // Call the contained handler. + return handler_.perform(ec, bytes_transferred); + } + + void complete(const boost::system::error_code& ec, + std::size_t bytes_transferred) + { + if (completed_.get()) + handler_.complete(ec, bytes_transferred); + } + + private: + socket_type descriptor_; + boost::shared_ptr<bool> completed_; + select_reactor<Own_Thread>& reactor_; + Handler handler_; + }; + + // Start new write and exception operations. The handler object will be + // invoked when the given descriptor is ready for writing or has exception + // information available, or an error has occurred. The handler will be called + // only once. + template <typename Handler> + void start_connect_op(socket_type descriptor, + per_descriptor_data&, Handler handler) + { + boost::asio::detail::mutex::scoped_lock lock(mutex_); + if (!shutdown_) + { + boost::shared_ptr<bool> completed(new bool(false)); + connect_handler_wrapper<Handler> wrapped_handler( + descriptor, completed, *this, handler); + bool interrupt = write_op_queue_.enqueue_operation( + descriptor, wrapped_handler); + interrupt = except_op_queue_.enqueue_operation( + descriptor, wrapped_handler) || interrupt; + if (interrupt) + interrupter_.interrupt(); + } + } + + // Cancel all operations associated with the given descriptor. The + // handlers associated with the descriptor will be invoked with the + // operation_aborted error. + void cancel_ops(socket_type descriptor, per_descriptor_data&) + { + boost::asio::detail::mutex::scoped_lock lock(mutex_); + cancel_ops_unlocked(descriptor); + } + + // Enqueue cancellation of all operations associated with the given + // descriptor. The handlers associated with the descriptor will be invoked + // with the operation_aborted error. This function does not acquire the + // select_reactor's mutex, and so should only be used when the reactor lock is + // already held. + void enqueue_cancel_ops_unlocked(socket_type descriptor) + { + pending_cancellations_.push_back(descriptor); + } + + // Cancel any operations that are running against the descriptor and remove + // its registration from the reactor. + void close_descriptor(socket_type descriptor, per_descriptor_data&) + { + boost::asio::detail::mutex::scoped_lock lock(mutex_); + cancel_ops_unlocked(descriptor); + } + + // Add a new timer queue to the reactor. + template <typename Time_Traits> + void add_timer_queue(timer_queue<Time_Traits>& timer_queue) + { + boost::asio::detail::mutex::scoped_lock lock(mutex_); + timer_queues_.push_back(&timer_queue); + } + + // Remove a timer queue from the reactor. + template <typename Time_Traits> + void remove_timer_queue(timer_queue<Time_Traits>& timer_queue) + { + boost::asio::detail::mutex::scoped_lock lock(mutex_); + for (std::size_t i = 0; i < timer_queues_.size(); ++i) + { + if (timer_queues_[i] == &timer_queue) + { + timer_queues_.erase(timer_queues_.begin() + i); + return; + } + } + } + + // Schedule a timer in the given timer queue to expire at the specified + // absolute time. The handler object will be invoked when the timer expires. + template <typename Time_Traits, typename Handler> + void schedule_timer(timer_queue<Time_Traits>& timer_queue, + const typename Time_Traits::time_type& time, Handler handler, void* token) + { + boost::asio::detail::mutex::scoped_lock lock(mutex_); + if (!shutdown_) + if (timer_queue.enqueue_timer(time, handler, token)) + interrupter_.interrupt(); + } + + // Cancel the timer associated with the given token. Returns the number of + // handlers that have been posted or dispatched. + template <typename Time_Traits> + std::size_t cancel_timer(timer_queue<Time_Traits>& timer_queue, void* token) + { + boost::asio::detail::mutex::scoped_lock lock(mutex_); + std::size_t n = timer_queue.cancel_timer(token); + if (n > 0) + interrupter_.interrupt(); + return n; + } + +private: + friend class task_io_service<select_reactor<Own_Thread> >; + + // Run select once until interrupted or events are ready to be dispatched. + void run(bool block) + { + boost::asio::detail::mutex::scoped_lock lock(mutex_); + + // Dispatch any operation cancellations that were made while the select + // loop was not running. + read_op_queue_.perform_cancellations(); + write_op_queue_.perform_cancellations(); + except_op_queue_.perform_cancellations(); + for (std::size_t i = 0; i < timer_queues_.size(); ++i) + timer_queues_[i]->dispatch_cancellations(); + + // Check if the thread is supposed to stop. + if (stop_thread_) + { + complete_operations_and_timers(lock); + return; + } + + // We can return immediately if there's no work to do and the reactor is + // not supposed to block. + if (!block && read_op_queue_.empty() && write_op_queue_.empty() + && except_op_queue_.empty() && all_timer_queues_are_empty()) + { + complete_operations_and_timers(lock); + return; + } + + // Set up the descriptor sets. + fd_set_adapter read_fds; + read_fds.set(interrupter_.read_descriptor()); + read_op_queue_.get_descriptors(read_fds); + fd_set_adapter write_fds; + write_op_queue_.get_descriptors(write_fds); + fd_set_adapter except_fds; + except_op_queue_.get_descriptors(except_fds); + socket_type max_fd = read_fds.max_descriptor(); + if (write_fds.max_descriptor() > max_fd) + max_fd = write_fds.max_descriptor(); + if (except_fds.max_descriptor() > max_fd) + max_fd = except_fds.max_descriptor(); + + // Block on the select call without holding the lock so that new + // operations can be started while the call is executing. + timeval tv_buf = { 0, 0 }; + timeval* tv = block ? get_timeout(tv_buf) : &tv_buf; + select_in_progress_ = true; + lock.unlock(); + boost::system::error_code ec; + int retval = socket_ops::select(static_cast<int>(max_fd + 1), + read_fds, write_fds, except_fds, tv, ec); + lock.lock(); + select_in_progress_ = false; + + // Block signals while dispatching operations. + boost::asio::detail::signal_blocker sb; + + // Reset the interrupter. + if (retval > 0 && read_fds.is_set(interrupter_.read_descriptor())) + interrupter_.reset(); + + // Dispatch all ready operations. + if (retval > 0) + { + // Exception operations must be processed first to ensure that any + // out-of-band data is read before normal data. + except_op_queue_.perform_operations_for_descriptors( + except_fds, boost::system::error_code()); + read_op_queue_.perform_operations_for_descriptors( + read_fds, boost::system::error_code()); + write_op_queue_.perform_operations_for_descriptors( + write_fds, boost::system::error_code()); + except_op_queue_.perform_cancellations(); + read_op_queue_.perform_cancellations(); + write_op_queue_.perform_cancellations(); + } + for (std::size_t i = 0; i < timer_queues_.size(); ++i) + { + timer_queues_[i]->dispatch_timers(); + timer_queues_[i]->dispatch_cancellations(); + } + + // Issue any pending cancellations. + for (size_t i = 0; i < pending_cancellations_.size(); ++i) + cancel_ops_unlocked(pending_cancellations_[i]); + pending_cancellations_.clear(); + + complete_operations_and_timers(lock); + } + + // Run the select loop in the thread. + void run_thread() + { + boost::asio::detail::mutex::scoped_lock lock(mutex_); + while (!stop_thread_) + { + lock.unlock(); + run(true); + lock.lock(); + } + } + + // Entry point for the select loop thread. + static void call_run_thread(select_reactor* reactor) + { + reactor->run_thread(); + } + + // Interrupt the select loop. + void interrupt() + { + interrupter_.interrupt(); + } + + // Check if all timer queues are empty. + bool all_timer_queues_are_empty() const + { + for (std::size_t i = 0; i < timer_queues_.size(); ++i) + if (!timer_queues_[i]->empty()) + return false; + return true; + } + + // Get the timeout value for the select call. + timeval* get_timeout(timeval& tv) + { + if (all_timer_queues_are_empty()) + return 0; + + // By default we will wait no longer than 5 minutes. This will ensure that + // any changes to the system clock are detected after no longer than this. + boost::posix_time::time_duration minimum_wait_duration + = boost::posix_time::minutes(5); + + for (std::size_t i = 0; i < timer_queues_.size(); ++i) + { + boost::posix_time::time_duration wait_duration + = timer_queues_[i]->wait_duration(); + if (wait_duration < minimum_wait_duration) + minimum_wait_duration = wait_duration; + } + + if (minimum_wait_duration > boost::posix_time::time_duration()) + { + tv.tv_sec = minimum_wait_duration.total_seconds(); + tv.tv_usec = minimum_wait_duration.total_microseconds() % 1000000; + } + else + { + tv.tv_sec = 0; + tv.tv_usec = 0; + } + + return &tv; + } + + // Cancel all operations associated with the given descriptor. The do_cancel + // function of the handler objects will be invoked. This function does not + // acquire the select_reactor's mutex. + void cancel_ops_unlocked(socket_type descriptor) + { + bool interrupt = read_op_queue_.cancel_operations(descriptor); + interrupt = write_op_queue_.cancel_operations(descriptor) || interrupt; + interrupt = except_op_queue_.cancel_operations(descriptor) || interrupt; + if (interrupt) + interrupter_.interrupt(); + } + + // Clean up operations and timers. We must not hold the lock since the + // destructors may make calls back into this reactor. We make a copy of the + // vector of timer queues since the original may be modified while the lock + // is not held. + void complete_operations_and_timers( + boost::asio::detail::mutex::scoped_lock& lock) + { + timer_queues_for_cleanup_ = timer_queues_; + lock.unlock(); + read_op_queue_.complete_operations(); + write_op_queue_.complete_operations(); + except_op_queue_.complete_operations(); + for (std::size_t i = 0; i < timer_queues_for_cleanup_.size(); ++i) + timer_queues_for_cleanup_[i]->complete_timers(); + } + + // Mutex to protect access to internal data. + boost::asio::detail::mutex mutex_; + + // Whether the select loop is currently running or not. + bool select_in_progress_; + + // The interrupter is used to break a blocking select call. + select_interrupter interrupter_; + + // The queue of read operations. + reactor_op_queue<socket_type> read_op_queue_; + + // The queue of write operations. + reactor_op_queue<socket_type> write_op_queue_; + + // The queue of exception operations. + reactor_op_queue<socket_type> except_op_queue_; + + // The timer queues. + std::vector<timer_queue_base*> timer_queues_; + + // A copy of the timer queues, used when cleaning up timers. The copy is + // stored as a class data member to avoid unnecessary memory allocation. + std::vector<timer_queue_base*> timer_queues_for_cleanup_; + + // The descriptors that are pending cancellation. + std::vector<socket_type> pending_cancellations_; + + // Does the reactor loop thread need to stop. + bool stop_thread_; + + // The thread that is running the reactor loop. + boost::asio::detail::thread* thread_; + + // Whether the service has been shut down. + bool shutdown_; +}; + +} // namespace detail +} // namespace asio +} // namespace boost + +#include <boost/asio/detail/pop_options.hpp> + +#endif // BOOST_ASIO_DETAIL_SELECT_REACTOR_HPP |