// | |
// detail/impl/task_io_service.ipp | |
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | |
// | |
// 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_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 |