asio/include/asio/detail/impl/scheduler.ipp - third_party/asio - Git at Google

 //
 // detail/impl/scheduler.ipp
 // ~~~~~~~~~~~~~~~~~~~~~~~~~
 //
 // Copyright (c) 2003-2016 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 ASIO_DETAIL_IMPL_SCHEDULER_IPP
 #define ASIO_DETAIL_IMPL_SCHEDULER_IPP

 #if defined(_MSC_VER) && (_MSC_VER >= 1200)
 # pragma once
 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)

 #include "asio/detail/config.hpp"

 #include "asio/detail/concurrency_hint.hpp"
 #include "asio/detail/event.hpp"
 #include "asio/detail/limits.hpp"
 #include "asio/detail/reactor.hpp"
 #include "asio/detail/scheduler.hpp"
 #include "asio/detail/scheduler_thread_info.hpp"

 #include "asio/detail/push_options.hpp"

 namespace asio {
 namespace detail {

 struct scheduler::task_cleanup
 {
   ~task_cleanup()
   {
     if (this_thread_->private_outstanding_work > 0)
     {
       asio::detail::increment(
           scheduler_->outstanding_work_,
           this_thread_->private_outstanding_work);
     }
     this_thread_->private_outstanding_work = 0;

     // Enqueue the completed operations and reinsert the task at the end of
     // the operation queue.
     lock_->lock();
     scheduler_->task_interrupted_ = true;
     scheduler_->op_queue_.push(this_thread_->private_op_queue);
     scheduler_->op_queue_.push(&scheduler_->task_operation_);
   }

   scheduler* scheduler_;
   mutex::scoped_lock* lock_;
   thread_info* this_thread_;
 };

 struct scheduler::work_cleanup
 {
   ~work_cleanup()
   {
     if (this_thread_->private_outstanding_work > 1)
     {
       asio::detail::increment(
           scheduler_->outstanding_work_,
           this_thread_->private_outstanding_work - 1);
     }
     else if (this_thread_->private_outstanding_work < 1)
     {
       scheduler_->work_finished();
     }
     this_thread_->private_outstanding_work = 0;

 #if defined(ASIO_HAS_THREADS)
     if (!this_thread_->private_op_queue.empty())
     {
       lock_->lock();
       scheduler_->op_queue_.push(this_thread_->private_op_queue);
     }
 #endif // defined(ASIO_HAS_THREADS)
   }

   scheduler* scheduler_;
   mutex::scoped_lock* lock_;
   thread_info* this_thread_;
 };

 scheduler::scheduler(
     asio::execution_context& ctx, int concurrency_hint)
   : asio::detail::execution_context_service_base<scheduler>(ctx),
     one_thread_(concurrency_hint == 1
         || !ASIO_CONCURRENCY_HINT_IS_LOCKING(
           SCHEDULER, concurrency_hint)),
     mutex_(ASIO_CONCURRENCY_HINT_IS_LOCKING(
           SCHEDULER, concurrency_hint)),
     task_(0),
     task_interrupted_(true),
     outstanding_work_(0),
     stopped_(false),
     shutdown_(false),
     concurrency_hint_(concurrency_hint)
 {
   ASIO_HANDLER_TRACKING_INIT;
 }

 void scheduler::shutdown()
 {
   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 scheduler::init_task()
 {
   mutex::scoped_lock lock(mutex_);
   if (!shutdown_ && !task_)
   {
     task_ = &use_service<reactor>(this->context());
     op_queue_.push(&task_operation_);
     wake_one_thread_and_unlock(lock);
   }
 }

 std::size_t scheduler::run(asio::error_code& ec)
 {
   ec = asio::error_code();
   if (outstanding_work_ == 0)
   {
     stop();
     return 0;
   }

   thread_info this_thread;
   this_thread.private_outstanding_work = 0;
   thread_call_stack::context ctx(this, this_thread);

   mutex::scoped_lock lock(mutex_);

   std::size_t n = 0;
   for (; do_run_one(lock, this_thread, ec); lock.lock())
     if (n != (std::numeric_limits<std::size_t>::max)())
       ++n;
   return n;
 }

 std::size_t scheduler::run_one(asio::error_code& ec)
 {
   ec = asio::error_code();
   if (outstanding_work_ == 0)
   {
     stop();
     return 0;
   }

   thread_info this_thread;
   this_thread.private_outstanding_work = 0;
   thread_call_stack::context ctx(this, this_thread);

   mutex::scoped_lock lock(mutex_);

   return do_run_one(lock, this_thread, ec);
 }

 std::size_t scheduler::wait_one(long usec, asio::error_code& ec)
 {
   ec = asio::error_code();
   if (outstanding_work_ == 0)
   {
     stop();
     return 0;
   }

   thread_info this_thread;
   this_thread.private_outstanding_work = 0;
   thread_call_stack::context ctx(this, this_thread);

   mutex::scoped_lock lock(mutex_);

   return do_wait_one(lock, this_thread, usec, ec);
 }

 std::size_t scheduler::poll(asio::error_code& ec)
 {
   ec = asio::error_code();
   if (outstanding_work_ == 0)
   {
     stop();
     return 0;
   }

   thread_info this_thread;
   this_thread.private_outstanding_work = 0;
   thread_call_stack::context ctx(this, this_thread);

   mutex::scoped_lock lock(mutex_);

 #if defined(ASIO_HAS_THREADS)
   // We want to support nested calls to poll() and poll_one(), so any handlers
   // that are already on a thread-private queue need to be put on to the main
   // queue now.
   if (one_thread_)
     if (thread_info* outer_info = static_cast<thread_info*>(ctx.next_by_key()))
       op_queue_.push(outer_info->private_op_queue);
 #endif // defined(ASIO_HAS_THREADS)

   std::size_t n = 0;
   for (; do_poll_one(lock, this_thread, ec); lock.lock())
     if (n != (std::numeric_limits<std::size_t>::max)())
       ++n;
   return n;
 }

 std::size_t scheduler::poll_one(asio::error_code& ec)
 {
   ec = asio::error_code();
   if (outstanding_work_ == 0)
   {
     stop();
     return 0;
   }

   thread_info this_thread;
   this_thread.private_outstanding_work = 0;
   thread_call_stack::context ctx(this, this_thread);

   mutex::scoped_lock lock(mutex_);

 #if defined(ASIO_HAS_THREADS)
   // We want to support nested calls to poll() and poll_one(), so any handlers
   // that are already on a thread-private queue need to be put on to the main
   // queue now.
   if (one_thread_)
     if (thread_info* outer_info = static_cast<thread_info*>(ctx.next_by_key()))
       op_queue_.push(outer_info->private_op_queue);
 #endif // defined(ASIO_HAS_THREADS)

   return do_poll_one(lock, this_thread, ec);
 }

 void scheduler::stop()
 {
   mutex::scoped_lock lock(mutex_);
   stop_all_threads(lock);
 }

 bool scheduler::stopped() const
 {
   mutex::scoped_lock lock(mutex_);
   return stopped_;
 }

 void scheduler::restart()
 {
   mutex::scoped_lock lock(mutex_);
   stopped_ = false;
 }

 void scheduler::compensating_work_started()
 {
   thread_info_base* this_thread = thread_call_stack::contains(this);
   ++static_cast<thread_info*>(this_thread)->private_outstanding_work;
 }

 void scheduler::post_immediate_completion(
     scheduler::operation* op, bool is_continuation)
 {
 #if defined(ASIO_HAS_THREADS)
   if (one_thread_ || is_continuation)
   {
     if (thread_info_base* this_thread = thread_call_stack::contains(this))
     {
       ++static_cast<thread_info*>(this_thread)->private_outstanding_work;
       static_cast<thread_info*>(this_thread)->private_op_queue.push(op);
       return;
     }
   }
 #else // defined(ASIO_HAS_THREADS)
   (void)is_continuation;
 #endif // defined(ASIO_HAS_THREADS)

   work_started();
   mutex::scoped_lock lock(mutex_);
   op_queue_.push(op);
   wake_one_thread_and_unlock(lock);
 }

 void scheduler::post_deferred_completion(scheduler::operation* op)
 {
 #if defined(ASIO_HAS_THREADS)
   if (one_thread_)
   {
     if (thread_info_base* this_thread = thread_call_stack::contains(this))
     {
       static_cast<thread_info*>(this_thread)->private_op_queue.push(op);
       return;
     }
   }
 #endif // defined(ASIO_HAS_THREADS)

   mutex::scoped_lock lock(mutex_);
   op_queue_.push(op);
   wake_one_thread_and_unlock(lock);
 }

 void scheduler::post_deferred_completions(
     op_queue<scheduler::operation>& ops)
 {
   if (!ops.empty())
   {
 #if defined(ASIO_HAS_THREADS)
     if (one_thread_)
     {
       if (thread_info_base* this_thread = thread_call_stack::contains(this))
       {
         static_cast<thread_info*>(this_thread)->private_op_queue.push(ops);
         return;
       }
     }
 #endif // defined(ASIO_HAS_THREADS)

     mutex::scoped_lock lock(mutex_);
     op_queue_.push(ops);
     wake_one_thread_and_unlock(lock);
   }
 }

 void scheduler::do_dispatch(
     scheduler::operation* op)
 {
   work_started();
   mutex::scoped_lock lock(mutex_);
   op_queue_.push(op);
   wake_one_thread_and_unlock(lock);
 }

 void scheduler::abandon_operations(
     op_queue<scheduler::operation>& ops)
 {
   op_queue<scheduler::operation> ops2;
   ops2.push(ops);
 }

 std::size_t scheduler::do_run_one(mutex::scoped_lock& lock,
     scheduler::thread_info& this_thread,
     const asio::error_code& ec)
 {
   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;

         if (more_handlers && !one_thread_)
           wakeup_event_.unlock_and_signal_one(lock);
         else
           lock.unlock();

         task_cleanup on_exit = { this, &lock, &this_thread };
         (void)on_exit;

         // 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 ? 0 : -1, this_thread.private_op_queue);
       }
       else
       {
         std::size_t task_result = o->task_result_;

         if (more_handlers && !one_thread_)
           wake_one_thread_and_unlock(lock);
         else
           lock.unlock();

         // Ensure the count of outstanding work is decremented on block exit.
         work_cleanup on_exit = { this, &lock, &this_thread };
         (void)on_exit;

         // Complete the operation. May throw an exception. Deletes the object.
         o->complete(this, ec, task_result);

         return 1;
       }
     }
     else
     {
       wakeup_event_.clear(lock);
       wakeup_event_.wait(lock);
     }
   }

   return 0;
 }

 std::size_t scheduler::do_wait_one(mutex::scoped_lock& lock,
     scheduler::thread_info& this_thread, long usec,
     const asio::error_code& ec)
 {
   if (stopped_)
     return 0;

   operation* o = op_queue_.front();
   if (o == 0)
   {
     wakeup_event_.clear(lock);
     wakeup_event_.wait_for_usec(lock, usec);
     usec = 0; // Wait at most once.
     o = op_queue_.front();
   }

   if (o == &task_operation_)
   {
     op_queue_.pop();
     bool more_handlers = (!op_queue_.empty());

     task_interrupted_ = more_handlers;

     if (more_handlers && !one_thread_)
       wakeup_event_.unlock_and_signal_one(lock);
     else
       lock.unlock();

     {
       task_cleanup on_exit = { this, &lock, &this_thread };
       (void)on_exit;

       // 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 ? 0 : usec, this_thread.private_op_queue);
     }

     o = op_queue_.front();
     if (o == &task_operation_)
     {
       if (!one_thread_)
         wakeup_event_.maybe_unlock_and_signal_one(lock);
       return 0;
     }
   }

   if (o == 0)
     return 0;

   op_queue_.pop();
   bool more_handlers = (!op_queue_.empty());

   std::size_t task_result = o->task_result_;

   if (more_handlers && !one_thread_)
     wake_one_thread_and_unlock(lock);
   else
     lock.unlock();

   // Ensure the count of outstanding work is decremented on block exit.
   work_cleanup on_exit = { this, &lock, &this_thread };
   (void)on_exit;

   // Complete the operation. May throw an exception. Deletes the object.
   o->complete(this, ec, task_result);

   return 1;
 }

 std::size_t scheduler::do_poll_one(mutex::scoped_lock& lock,
     scheduler::thread_info& this_thread,
     const asio::error_code& ec)
 {
   if (stopped_)
     return 0;

   operation* o = op_queue_.front();
   if (o == &task_operation_)
   {
     op_queue_.pop();
     lock.unlock();

     {
       task_cleanup c = { this, &lock, &this_thread };
       (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(0, this_thread.private_op_queue);
     }

     o = op_queue_.front();
     if (o == &task_operation_)
     {
       wakeup_event_.maybe_unlock_and_signal_one(lock);
       return 0;
     }
   }

   if (o == 0)
     return 0;

   op_queue_.pop();
   bool more_handlers = (!op_queue_.empty());

   std::size_t task_result = o->task_result_;

   if (more_handlers && !one_thread_)
     wake_one_thread_and_unlock(lock);
   else
     lock.unlock();

   // Ensure the count of outstanding work is decremented on block exit.
   work_cleanup on_exit = { this, &lock, &this_thread };
   (void)on_exit;

   // Complete the operation. May throw an exception. Deletes the object.
   o->complete(this, ec, task_result);

   return 1;
 }

 void scheduler::stop_all_threads(
     mutex::scoped_lock& lock)
 {
   stopped_ = true;
   wakeup_event_.signal_all(lock);

   if (!task_interrupted_ && task_)
   {
     task_interrupted_ = true;
     task_->interrupt();
   }
 }

 void scheduler::wake_one_thread_and_unlock(
     mutex::scoped_lock& lock)
 {
   if (!wakeup_event_.maybe_unlock_and_signal_one(lock))
   {
     if (!task_interrupted_ && task_)
     {
       task_interrupted_ = true;
       task_->interrupt();
     }
     lock.unlock();
   }
 }

 } // namespace detail
 } // namespace asio

 #include "asio/detail/pop_options.hpp"

 #endif // ASIO_DETAIL_IMPL_SCHEDULER_IPP
	//
	// detail/impl/scheduler.ipp
	// ~~~~~~~~~~~~~~~~~~~~~~~~~
	//
	// Copyright (c) 2003-2016 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 ASIO_DETAIL_IMPL_SCHEDULER_IPP
	#define ASIO_DETAIL_IMPL_SCHEDULER_IPP

	#if defined(_MSC_VER) && (_MSC_VER >= 1200)
	# pragma once
	#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)

	#include "asio/detail/config.hpp"

	#include "asio/detail/concurrency_hint.hpp"
	#include "asio/detail/event.hpp"
	#include "asio/detail/limits.hpp"
	#include "asio/detail/reactor.hpp"
	#include "asio/detail/scheduler.hpp"
	#include "asio/detail/scheduler_thread_info.hpp"

	#include "asio/detail/push_options.hpp"

	namespace asio {
	namespace detail {

	struct scheduler::task_cleanup
	{
	~task_cleanup()
	{
	if (this_thread_->private_outstanding_work > 0)
	{
	asio::detail::increment(
	scheduler_->outstanding_work_,
	this_thread_->private_outstanding_work);
	}
	this_thread_->private_outstanding_work = 0;

	// Enqueue the completed operations and reinsert the task at the end of
	// the operation queue.
	lock_->lock();
	scheduler_->task_interrupted_ = true;
	scheduler_->op_queue_.push(this_thread_->private_op_queue);
	scheduler_->op_queue_.push(&scheduler_->task_operation_);
	}

	scheduler* scheduler_;
	mutex::scoped_lock* lock_;
	thread_info* this_thread_;
	};

	struct scheduler::work_cleanup
	{
	~work_cleanup()
	{
	if (this_thread_->private_outstanding_work > 1)
	{
	asio::detail::increment(
	scheduler_->outstanding_work_,
	this_thread_->private_outstanding_work - 1);
	}
	else if (this_thread_->private_outstanding_work < 1)
	{
	scheduler_->work_finished();
	}
	this_thread_->private_outstanding_work = 0;

	#if defined(ASIO_HAS_THREADS)
	if (!this_thread_->private_op_queue.empty())
	{
	lock_->lock();
	scheduler_->op_queue_.push(this_thread_->private_op_queue);
	}
	#endif // defined(ASIO_HAS_THREADS)
	}

	scheduler* scheduler_;
	mutex::scoped_lock* lock_;
	thread_info* this_thread_;
	};

	scheduler::scheduler(
	asio::execution_context& ctx, int concurrency_hint)
	: asio::detail::execution_context_service_base<scheduler>(ctx),
	one_thread_(concurrency_hint == 1
	\|\| !ASIO_CONCURRENCY_HINT_IS_LOCKING(
	SCHEDULER, concurrency_hint)),
	mutex_(ASIO_CONCURRENCY_HINT_IS_LOCKING(
	SCHEDULER, concurrency_hint)),
	task_(0),
	task_interrupted_(true),
	outstanding_work_(0),
	stopped_(false),
	shutdown_(false),
	concurrency_hint_(concurrency_hint)
	{
	ASIO_HANDLER_TRACKING_INIT;
	}

	void scheduler::shutdown()
	{
	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 scheduler::init_task()
	{
	mutex::scoped_lock lock(mutex_);
	if (!shutdown_ && !task_)
	{
	task_ = &use_service<reactor>(this->context());
	op_queue_.push(&task_operation_);
	wake_one_thread_and_unlock(lock);
	}
	}

	std::size_t scheduler::run(asio::error_code& ec)
	{
	ec = asio::error_code();
	if (outstanding_work_ == 0)
	{
	stop();
	return 0;
	}

	thread_info this_thread;
	this_thread.private_outstanding_work = 0;
	thread_call_stack::context ctx(this, this_thread);

	mutex::scoped_lock lock(mutex_);

	std::size_t n = 0;
	for (; do_run_one(lock, this_thread, ec); lock.lock())
	if (n != (std::numeric_limits<std::size_t>::max)())
	++n;
	return n;
	}

	std::size_t scheduler::run_one(asio::error_code& ec)
	{
	ec = asio::error_code();
	if (outstanding_work_ == 0)
	{
	stop();
	return 0;
	}

	thread_info this_thread;
	this_thread.private_outstanding_work = 0;
	thread_call_stack::context ctx(this, this_thread);

	mutex::scoped_lock lock(mutex_);

	return do_run_one(lock, this_thread, ec);
	}

	std::size_t scheduler::wait_one(long usec, asio::error_code& ec)
	{
	ec = asio::error_code();
	if (outstanding_work_ == 0)
	{
	stop();
	return 0;
	}

	thread_info this_thread;
	this_thread.private_outstanding_work = 0;
	thread_call_stack::context ctx(this, this_thread);

	mutex::scoped_lock lock(mutex_);

	return do_wait_one(lock, this_thread, usec, ec);
	}

	std::size_t scheduler::poll(asio::error_code& ec)
	{
	ec = asio::error_code();
	if (outstanding_work_ == 0)
	{
	stop();
	return 0;
	}

	thread_info this_thread;
	this_thread.private_outstanding_work = 0;
	thread_call_stack::context ctx(this, this_thread);

	mutex::scoped_lock lock(mutex_);

	#if defined(ASIO_HAS_THREADS)
	// We want to support nested calls to poll() and poll_one(), so any handlers
	// that are already on a thread-private queue need to be put on to the main
	// queue now.
	if (one_thread_)
	if (thread_info* outer_info = static_cast<thread_info*>(ctx.next_by_key()))
	op_queue_.push(outer_info->private_op_queue);
	#endif // defined(ASIO_HAS_THREADS)

	std::size_t n = 0;
	for (; do_poll_one(lock, this_thread, ec); lock.lock())
	if (n != (std::numeric_limits<std::size_t>::max)())
	++n;
	return n;
	}

	std::size_t scheduler::poll_one(asio::error_code& ec)
	{
	ec = asio::error_code();
	if (outstanding_work_ == 0)
	{
	stop();
	return 0;
	}

	thread_info this_thread;
	this_thread.private_outstanding_work = 0;
	thread_call_stack::context ctx(this, this_thread);

	mutex::scoped_lock lock(mutex_);

	#if defined(ASIO_HAS_THREADS)
	// We want to support nested calls to poll() and poll_one(), so any handlers
	// that are already on a thread-private queue need to be put on to the main
	// queue now.
	if (one_thread_)
	if (thread_info* outer_info = static_cast<thread_info*>(ctx.next_by_key()))
	op_queue_.push(outer_info->private_op_queue);
	#endif // defined(ASIO_HAS_THREADS)

	return do_poll_one(lock, this_thread, ec);
	}

	void scheduler::stop()
	{
	mutex::scoped_lock lock(mutex_);
	stop_all_threads(lock);
	}

	bool scheduler::stopped() const
	{
	mutex::scoped_lock lock(mutex_);
	return stopped_;
	}

	void scheduler::restart()
	{
	mutex::scoped_lock lock(mutex_);
	stopped_ = false;
	}

	void scheduler::compensating_work_started()
	{
	thread_info_base* this_thread = thread_call_stack::contains(this);
	++static_cast<thread_info*>(this_thread)->private_outstanding_work;
	}

	void scheduler::post_immediate_completion(
	scheduler::operation* op, bool is_continuation)
	{
	#if defined(ASIO_HAS_THREADS)
	if (one_thread_ \|\| is_continuation)
	{
	if (thread_info_base* this_thread = thread_call_stack::contains(this))
	{
	++static_cast<thread_info*>(this_thread)->private_outstanding_work;
	static_cast<thread_info*>(this_thread)->private_op_queue.push(op);
	return;
	}
	}
	#else // defined(ASIO_HAS_THREADS)
	(void)is_continuation;
	#endif // defined(ASIO_HAS_THREADS)

	work_started();
	mutex::scoped_lock lock(mutex_);
	op_queue_.push(op);
	wake_one_thread_and_unlock(lock);
	}

	void scheduler::post_deferred_completion(scheduler::operation* op)
	{
	#if defined(ASIO_HAS_THREADS)
	if (one_thread_)
	{
	if (thread_info_base* this_thread = thread_call_stack::contains(this))
	{
	static_cast<thread_info*>(this_thread)->private_op_queue.push(op);
	return;
	}
	}
	#endif // defined(ASIO_HAS_THREADS)

	mutex::scoped_lock lock(mutex_);
	op_queue_.push(op);
	wake_one_thread_and_unlock(lock);
	}

	void scheduler::post_deferred_completions(
	op_queue<scheduler::operation>& ops)
	{
	if (!ops.empty())
	{
	#if defined(ASIO_HAS_THREADS)
	if (one_thread_)
	{
	if (thread_info_base* this_thread = thread_call_stack::contains(this))
	{
	static_cast<thread_info*>(this_thread)->private_op_queue.push(ops);
	return;
	}
	}
	#endif // defined(ASIO_HAS_THREADS)

	mutex::scoped_lock lock(mutex_);
	op_queue_.push(ops);
	wake_one_thread_and_unlock(lock);
	}
	}

	void scheduler::do_dispatch(
	scheduler::operation* op)
	{
	work_started();
	mutex::scoped_lock lock(mutex_);
	op_queue_.push(op);
	wake_one_thread_and_unlock(lock);
	}

	void scheduler::abandon_operations(
	op_queue<scheduler::operation>& ops)
	{
	op_queue<scheduler::operation> ops2;
	ops2.push(ops);
	}

	std::size_t scheduler::do_run_one(mutex::scoped_lock& lock,
	scheduler::thread_info& this_thread,
	const asio::error_code& ec)
	{
	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;

	if (more_handlers && !one_thread_)
	wakeup_event_.unlock_and_signal_one(lock);
	else
	lock.unlock();

	task_cleanup on_exit = { this, &lock, &this_thread };
	(void)on_exit;

	// 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 ? 0 : -1, this_thread.private_op_queue);
	}
	else
	{
	std::size_t task_result = o->task_result_;

	if (more_handlers && !one_thread_)
	wake_one_thread_and_unlock(lock);
	else
	lock.unlock();

	// Ensure the count of outstanding work is decremented on block exit.
	work_cleanup on_exit = { this, &lock, &this_thread };
	(void)on_exit;

	// Complete the operation. May throw an exception. Deletes the object.
	o->complete(this, ec, task_result);

	return 1;
	}
	}
	else
	{
	wakeup_event_.clear(lock);
	wakeup_event_.wait(lock);
	}
	}

	return 0;
	}

	std::size_t scheduler::do_wait_one(mutex::scoped_lock& lock,
	scheduler::thread_info& this_thread, long usec,
	const asio::error_code& ec)
	{
	if (stopped_)
	return 0;

	operation* o = op_queue_.front();
	if (o == 0)
	{
	wakeup_event_.clear(lock);
	wakeup_event_.wait_for_usec(lock, usec);
	usec = 0; // Wait at most once.
	o = op_queue_.front();
	}

	if (o == &task_operation_)
	{
	op_queue_.pop();
	bool more_handlers = (!op_queue_.empty());

	task_interrupted_ = more_handlers;

	if (more_handlers && !one_thread_)
	wakeup_event_.unlock_and_signal_one(lock);
	else
	lock.unlock();

	{
	task_cleanup on_exit = { this, &lock, &this_thread };
	(void)on_exit;

	// 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 ? 0 : usec, this_thread.private_op_queue);
	}

	o = op_queue_.front();
	if (o == &task_operation_)
	{
	if (!one_thread_)
	wakeup_event_.maybe_unlock_and_signal_one(lock);
	return 0;
	}
	}

	if (o == 0)
	return 0;

	op_queue_.pop();
	bool more_handlers = (!op_queue_.empty());

	std::size_t task_result = o->task_result_;

	if (more_handlers && !one_thread_)
	wake_one_thread_and_unlock(lock);
	else
	lock.unlock();

	// Ensure the count of outstanding work is decremented on block exit.
	work_cleanup on_exit = { this, &lock, &this_thread };
	(void)on_exit;

	// Complete the operation. May throw an exception. Deletes the object.
	o->complete(this, ec, task_result);

	return 1;
	}

	std::size_t scheduler::do_poll_one(mutex::scoped_lock& lock,
	scheduler::thread_info& this_thread,
	const asio::error_code& ec)
	{
	if (stopped_)
	return 0;

	operation* o = op_queue_.front();
	if (o == &task_operation_)
	{
	op_queue_.pop();
	lock.unlock();

	{
	task_cleanup c = { this, &lock, &this_thread };
	(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(0, this_thread.private_op_queue);
	}

	o = op_queue_.front();
	if (o == &task_operation_)
	{
	wakeup_event_.maybe_unlock_and_signal_one(lock);
	return 0;
	}
	}

	if (o == 0)
	return 0;

	op_queue_.pop();
	bool more_handlers = (!op_queue_.empty());

	std::size_t task_result = o->task_result_;

	if (more_handlers && !one_thread_)
	wake_one_thread_and_unlock(lock);
	else
	lock.unlock();

	// Ensure the count of outstanding work is decremented on block exit.
	work_cleanup on_exit = { this, &lock, &this_thread };
	(void)on_exit;

	// Complete the operation. May throw an exception. Deletes the object.
	o->complete(this, ec, task_result);

	return 1;
	}

	void scheduler::stop_all_threads(
	mutex::scoped_lock& lock)
	{
	stopped_ = true;
	wakeup_event_.signal_all(lock);

	if (!task_interrupted_ && task_)
	{
	task_interrupted_ = true;
	task_->interrupt();
	}
	}

	void scheduler::wake_one_thread_and_unlock(
	mutex::scoped_lock& lock)
	{
	if (!wakeup_event_.maybe_unlock_and_signal_one(lock))
	{
	if (!task_interrupted_ && task_)
	{
	task_interrupted_ = true;
	task_->interrupt();
	}
	lock.unlock();
	}
	}

	} // namespace detail
	} // namespace asio

	#include "asio/detail/pop_options.hpp"

	#endif // ASIO_DETAIL_IMPL_SCHEDULER_IPP