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diff --git a/boost/asio/detail/impl/strand_service.ipp b/boost/asio/detail/impl/strand_service.ipp
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+//
+// detail/impl/strand_service.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2012 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_STRAND_SERVICE_IPP
+#define BOOST_ASIO_DETAIL_IMPL_STRAND_SERVICE_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include <boost/asio/detail/config.hpp>
+#include <boost/asio/detail/call_stack.hpp>
+#include <boost/asio/detail/strand_service.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+namespace detail {
+
+struct strand_service::on_do_complete_exit
+{
+  io_service_impl* owner_;
+  strand_impl* impl_;
+
+  ~on_do_complete_exit()
+  {
+    impl_->mutex_.lock();
+    impl_->ready_queue_.push(impl_->waiting_queue_);
+    bool more_handlers = impl_->locked_ = !impl_->ready_queue_.empty();
+    impl_->mutex_.unlock();
+
+    if (more_handlers)
+      owner_->post_immediate_completion(impl_);
+  }
+};
+
+strand_service::strand_service(boost::asio::io_service& io_service)
+  : boost::asio::detail::service_base<strand_service>(io_service),
+    io_service_(boost::asio::use_service<io_service_impl>(io_service)),
+    mutex_(),
+    salt_(0)
+{
+}
+
+void strand_service::shutdown_service()
+{
+  op_queue<operation> ops;
+
+  boost::asio::detail::mutex::scoped_lock lock(mutex_);
+
+  for (std::size_t i = 0; i < num_implementations; ++i)
+  {
+    if (strand_impl* impl = implementations_[i].get())
+    {
+      ops.push(impl->waiting_queue_);
+      ops.push(impl->ready_queue_);
+    }
+  }
+}
+
+void strand_service::construct(strand_service::implementation_type& impl)
+{
+  boost::asio::detail::mutex::scoped_lock lock(mutex_);
+
+  std::size_t salt = salt_++;
+#if defined(BOOST_ASIO_ENABLE_SEQUENTIAL_STRAND_ALLOCATION)
+  std::size_t index = salt;
+#else // defined(BOOST_ASIO_ENABLE_SEQUENTIAL_STRAND_ALLOCATION)
+  std::size_t index = reinterpret_cast<std::size_t>(&impl);
+  index += (reinterpret_cast<std::size_t>(&impl) >> 3);
+  index ^= salt + 0x9e3779b9 + (index << 6) + (index >> 2);
+#endif // defined(BOOST_ASIO_ENABLE_SEQUENTIAL_STRAND_ALLOCATION)
+  index = index % num_implementations;
+
+  if (!implementations_[index].get())
+    implementations_[index].reset(new strand_impl);
+  impl = implementations_[index].get();
+}
+
+bool strand_service::do_dispatch(implementation_type& impl, operation* op)
+{
+  // If we are running inside the io_service, and no other handler already
+  // holds the strand lock, then the handler can run immediately.
+  bool can_dispatch = io_service_.can_dispatch();
+  impl->mutex_.lock();
+  if (can_dispatch && !impl->locked_)
+  {
+    // Immediate invocation is allowed.
+    impl->locked_ = true;
+    impl->mutex_.unlock();
+    return true;
+  }
+
+  if (impl->locked_)
+  {
+    // Some other handler already holds the strand lock. Enqueue for later.
+    impl->waiting_queue_.push(op);
+    impl->mutex_.unlock();
+  }
+  else
+  {
+    // The handler is acquiring the strand lock and so is responsible for
+    // scheduling the strand.
+    impl->locked_ = true;
+    impl->mutex_.unlock();
+    impl->ready_queue_.push(op);
+    io_service_.post_immediate_completion(impl);
+  }
+
+  return false;
+}
+
+void strand_service::do_post(implementation_type& impl, operation* op)
+{
+  impl->mutex_.lock();
+  if (impl->locked_)
+  {
+    // Some other handler already holds the strand lock. Enqueue for later.
+    impl->waiting_queue_.push(op);
+    impl->mutex_.unlock();
+  }
+  else
+  {
+    // The handler is acquiring the strand lock and so is responsible for
+    // scheduling the strand.
+    impl->locked_ = true;
+    impl->mutex_.unlock();
+    impl->ready_queue_.push(op);
+    io_service_.post_immediate_completion(impl);
+  }
+}
+
+void strand_service::do_complete(io_service_impl* owner, operation* base,
+    const boost::system::error_code& ec, std::size_t /*bytes_transferred*/)
+{
+  if (owner)
+  {
+    strand_impl* impl = static_cast<strand_impl*>(base);
+
+    // Indicate that this strand is executing on the current thread.
+    call_stack<strand_impl>::context ctx(impl);
+
+    // Ensure the next handler, if any, is scheduled on block exit.
+    on_do_complete_exit on_exit = { owner, impl };
+    (void)on_exit;
+
+    // Run all ready handlers. No lock is required since the ready queue is
+    // accessed only within the strand.
+    while (operation* o = impl->ready_queue_.front())
+    {
+      impl->ready_queue_.pop();
+      o->complete(*owner, ec, 0);
+    }
+  }
+}
+
+} // namespace detail
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#endif // BOOST_ASIO_DETAIL_IMPL_STRAND_SERVICE_IPP