| // |
| // detail/impl/task_io_service.ipp |
| // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| // |
| // Copyright (c) 2003-2010 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_IMPL_TASK_IO_SERVICE_IPP |
| #define BOOST_ASIO_DETAIL_IMPL_TASK_IO_SERVICE_IPP |
| |
| #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/limits.hpp> |
| #include <boost/asio/detail/call_stack.hpp> |
| #include <boost/asio/detail/event.hpp> |
| #include <boost/asio/detail/reactor.hpp> |
| #include <boost/asio/detail/task_io_service.hpp> |
| |
| #include <boost/asio/detail/push_options.hpp> |
| |
| namespace boost { |
| namespace asio { |
| namespace detail { |
| |
| struct task_io_service::task_cleanup |
| { |
| ~task_cleanup() |
| { |
| // Enqueue the completed operations and reinsert the task at the end of |
| // the operation queue. |
| lock_->lock(); |
| task_io_service_->task_interrupted_ = true; |
| task_io_service_->op_queue_.push(*ops_); |
| task_io_service_->op_queue_.push(&task_io_service_->task_operation_); |
| } |
| |
| task_io_service* task_io_service_; |
| mutex::scoped_lock* lock_; |
| op_queue<operation>* ops_; |
| }; |
| |
| struct task_io_service::work_finished_on_block_exit |
| { |
| ~work_finished_on_block_exit() |
| { |
| task_io_service_->work_finished(); |
| } |
| |
| task_io_service* task_io_service_; |
| }; |
| |
| struct task_io_service::idle_thread_info |
| { |
| event wakeup_event; |
| idle_thread_info* next; |
| }; |
| |
| task_io_service::task_io_service(boost::asio::io_service& io_service) |
| : boost::asio::detail::service_base<task_io_service>(io_service), |
| mutex_(), |
| task_(0), |
| task_interrupted_(true), |
| outstanding_work_(0), |
| stopped_(false), |
| shutdown_(false), |
| first_idle_thread_(0) |
| { |
| } |
| |
| void task_io_service::init(std::size_t /*concurrency_hint*/) |
| { |
| } |
| |
| void task_io_service::shutdown_service() |
| { |
| mutex::scoped_lock lock(mutex_); |
| shutdown_ = true; |
| lock.unlock(); |
| |
| // Destroy handler objects. |
| while (!op_queue_.empty()) |
| { |
| operation* o = op_queue_.front(); |
| op_queue_.pop(); |
| if (o != &task_operation_) |
| o->destroy(); |
| } |
| |
| // Reset to initial state. |
| task_ = 0; |
| } |
| |
| void task_io_service::init_task() |
| { |
| mutex::scoped_lock lock(mutex_); |
| if (!shutdown_ && !task_) |
| { |
| task_ = &use_service<reactor>(this->get_io_service()); |
| op_queue_.push(&task_operation_); |
| wake_one_thread_and_unlock(lock); |
| } |
| } |
| |
| std::size_t task_io_service::run(boost::system::error_code& ec) |
| { |
| ec = boost::system::error_code(); |
| if (outstanding_work_ == 0) |
| { |
| stop(); |
| return 0; |
| } |
| |
| call_stack<task_io_service>::context ctx(this); |
| |
| idle_thread_info this_idle_thread; |
| this_idle_thread.next = 0; |
| |
| mutex::scoped_lock lock(mutex_); |
| |
| std::size_t n = 0; |
| for (; do_one(lock, &this_idle_thread); lock.lock()) |
| if (n != (std::numeric_limits<std::size_t>::max)()) |
| ++n; |
| return n; |
| } |
| |
| std::size_t task_io_service::run_one(boost::system::error_code& ec) |
| { |
| ec = boost::system::error_code(); |
| if (outstanding_work_ == 0) |
| { |
| stop(); |
| return 0; |
| } |
| |
| call_stack<task_io_service>::context ctx(this); |
| |
| idle_thread_info this_idle_thread; |
| this_idle_thread.next = 0; |
| |
| mutex::scoped_lock lock(mutex_); |
| |
| return do_one(lock, &this_idle_thread); |
| } |
| |
| std::size_t task_io_service::poll(boost::system::error_code& ec) |
| { |
| if (outstanding_work_ == 0) |
| { |
| stop(); |
| ec = boost::system::error_code(); |
| return 0; |
| } |
| |
| call_stack<task_io_service>::context ctx(this); |
| |
| mutex::scoped_lock lock(mutex_); |
| |
| std::size_t n = 0; |
| for (; do_one(lock, 0); lock.lock()) |
| if (n != (std::numeric_limits<std::size_t>::max)()) |
| ++n; |
| return n; |
| } |
| |
| std::size_t task_io_service::poll_one(boost::system::error_code& ec) |
| { |
| ec = boost::system::error_code(); |
| if (outstanding_work_ == 0) |
| { |
| stop(); |
| return 0; |
| } |
| |
| call_stack<task_io_service>::context ctx(this); |
| |
| mutex::scoped_lock lock(mutex_); |
| |
| return do_one(lock, 0); |
| } |
| |
| void task_io_service::stop() |
| { |
| mutex::scoped_lock lock(mutex_); |
| stop_all_threads(lock); |
| } |
| |
| void task_io_service::reset() |
| { |
| mutex::scoped_lock lock(mutex_); |
| stopped_ = false; |
| } |
| |
| void task_io_service::post_immediate_completion(task_io_service::operation* op) |
| { |
| work_started(); |
| post_deferred_completion(op); |
| } |
| |
| void task_io_service::post_deferred_completion(task_io_service::operation* op) |
| { |
| mutex::scoped_lock lock(mutex_); |
| op_queue_.push(op); |
| wake_one_thread_and_unlock(lock); |
| } |
| |
| void task_io_service::post_deferred_completions( |
| op_queue<task_io_service::operation>& ops) |
| { |
| if (!ops.empty()) |
| { |
| mutex::scoped_lock lock(mutex_); |
| op_queue_.push(ops); |
| wake_one_thread_and_unlock(lock); |
| } |
| } |
| |
| std::size_t task_io_service::do_one(mutex::scoped_lock& lock, |
| task_io_service::idle_thread_info* this_idle_thread) |
| { |
| bool polling = !this_idle_thread; |
| bool task_has_run = false; |
| while (!stopped_) |
| { |
| if (!op_queue_.empty()) |
| { |
| // Prepare to execute first handler from queue. |
| operation* o = op_queue_.front(); |
| op_queue_.pop(); |
| bool more_handlers = (!op_queue_.empty()); |
| |
| if (o == &task_operation_) |
| { |
| task_interrupted_ = more_handlers || polling; |
| |
| // If the task has already run and we're polling then we're done. |
| if (task_has_run && polling) |
| { |
| task_interrupted_ = true; |
| op_queue_.push(&task_operation_); |
| return 0; |
| } |
| task_has_run = true; |
| |
| if (!more_handlers || !wake_one_idle_thread_and_unlock(lock)) |
| lock.unlock(); |
| |
| op_queue<operation> completed_ops; |
| task_cleanup c = { this, &lock, &completed_ops }; |
| (void)c; |
| |
| // Run the task. May throw an exception. Only block if the operation |
| // queue is empty and we're not polling, otherwise we want to return |
| // as soon as possible. |
| task_->run(!more_handlers && !polling, completed_ops); |
| } |
| else |
| { |
| if (more_handlers) |
| wake_one_thread_and_unlock(lock); |
| else |
| lock.unlock(); |
| |
| // Ensure the count of outstanding work is decremented on block exit. |
| work_finished_on_block_exit on_exit = { this }; |
| (void)on_exit; |
| |
| // Complete the operation. May throw an exception. |
| o->complete(*this); // deletes the operation object |
| |
| return 1; |
| } |
| } |
| else if (this_idle_thread) |
| { |
| // Nothing to run right now, so just wait for work to do. |
| this_idle_thread->next = first_idle_thread_; |
| first_idle_thread_ = this_idle_thread; |
| this_idle_thread->wakeup_event.clear(lock); |
| this_idle_thread->wakeup_event.wait(lock); |
| } |
| else |
| { |
| return 0; |
| } |
| } |
| |
| return 0; |
| } |
| |
| void task_io_service::stop_all_threads( |
| mutex::scoped_lock& lock) |
| { |
| stopped_ = true; |
| |
| while (first_idle_thread_) |
| { |
| idle_thread_info* idle_thread = first_idle_thread_; |
| first_idle_thread_ = idle_thread->next; |
| idle_thread->next = 0; |
| idle_thread->wakeup_event.signal(lock); |
| } |
| |
| if (!task_interrupted_ && task_) |
| { |
| task_interrupted_ = true; |
| task_->interrupt(); |
| } |
| } |
| |
| bool task_io_service::wake_one_idle_thread_and_unlock( |
| mutex::scoped_lock& lock) |
| { |
| if (first_idle_thread_) |
| { |
| idle_thread_info* idle_thread = first_idle_thread_; |
| first_idle_thread_ = idle_thread->next; |
| idle_thread->next = 0; |
| idle_thread->wakeup_event.signal_and_unlock(lock); |
| return true; |
| } |
| return false; |
| } |
| |
| void task_io_service::wake_one_thread_and_unlock( |
| mutex::scoped_lock& lock) |
| { |
| if (!wake_one_idle_thread_and_unlock(lock)) |
| { |
| if (!task_interrupted_ && task_) |
| { |
| task_interrupted_ = true; |
| task_->interrupt(); |
| } |
| lock.unlock(); |
| } |
| } |
| |
| } // namespace detail |
| } // namespace asio |
| } // namespace boost |
| |
| #include <boost/asio/detail/pop_options.hpp> |
| |
| #endif // !defined(BOOST_ASIO_HAS_IOCP) |
| |
| #endif // BOOST_ASIO_DETAIL_IMPL_TASK_IO_SERVICE_IPP |