boost/asio/detail/impl/select_reactor.ipp

   1 //
   2 // detail/impl/select_reactor.ipp
   3 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2014 Christopher M. Kohlhoff (chris at kohlhoff dot com)
   6 //
   7 // Distributed under the Boost Software License, Version 1.0. (See accompanying
   8 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   9 //
  10
  11 #ifndef BOOST_ASIO_DETAIL_IMPL_SELECT_REACTOR_IPP
  12 #define BOOST_ASIO_DETAIL_IMPL_SELECT_REACTOR_IPP
  13
  14 #if defined(_MSC_VER) && (_MSC_VER >= 1200)
  15 # pragma once
  16 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
  17
  18 #include <boost/asio/detail/config.hpp>
  19
  20 #if defined(BOOST_ASIO_HAS_IOCP) \
  21   || (!defined(BOOST_ASIO_HAS_DEV_POLL) \
  22       && !defined(BOOST_ASIO_HAS_EPOLL) \
  23       && !defined(BOOST_ASIO_HAS_KQUEUE) \
  24       && !defined(BOOST_ASIO_WINDOWS_RUNTIME))
  25
  26 #include <boost/asio/detail/bind_handler.hpp>
  27 #include <boost/asio/detail/fd_set_adapter.hpp>
  28 #include <boost/asio/detail/select_reactor.hpp>
  29 #include <boost/asio/detail/signal_blocker.hpp>
  30 #include <boost/asio/detail/socket_ops.hpp>
  31
  32 #include <boost/asio/detail/push_options.hpp>
  33
  34 namespace boost {
  35 namespace asio {
  36 namespace detail {
  37
  38 select_reactor::select_reactor(boost::asio::io_service& io_service)
  39   : boost::asio::detail::service_base<select_reactor>(io_service),
  40     io_service_(use_service<io_service_impl>(io_service)),
  41     mutex_(),
  42     interrupter_(),
  43 #if defined(BOOST_ASIO_HAS_IOCP)
  44     stop_thread_(false),
  45     thread_(0),
  46 #endif // defined(BOOST_ASIO_HAS_IOCP)
  47     shutdown_(false)
  48 {
  49 #if defined(BOOST_ASIO_HAS_IOCP)
  50   boost::asio::detail::signal_blocker sb;
  51   thread_ = new boost::asio::detail::thread(
  52       bind_handler(&select_reactor::call_run_thread, this));
  53 #endif // defined(BOOST_ASIO_HAS_IOCP)
  54 }
  55
  56 select_reactor::~select_reactor()
  57 {
  58   shutdown_service();
  59 }
  60
  61 void select_reactor::shutdown_service()
  62 {
  63   boost::asio::detail::mutex::scoped_lock lock(mutex_);
  64   shutdown_ = true;
  65 #if defined(BOOST_ASIO_HAS_IOCP)
  66   stop_thread_ = true;
  67 #endif // defined(BOOST_ASIO_HAS_IOCP)
  68   lock.unlock();
  69
  70 #if defined(BOOST_ASIO_HAS_IOCP)
  71   if (thread_)
  72   {
  73     interrupter_.interrupt();
  74     thread_->join();
  75     delete thread_;
  76     thread_ = 0;
  77   }
  78 #endif // defined(BOOST_ASIO_HAS_IOCP)
  79
  80   op_queue<operation> ops;
  81
  82   for (int i = 0; i < max_ops; ++i)
  83     op_queue_[i].get_all_operations(ops);
  84
  85   timer_queues_.get_all_timers(ops);
  86
  87   io_service_.abandon_operations(ops);
  88 }
  89
  90 void select_reactor::fork_service(boost::asio::io_service::fork_event fork_ev)
  91 {
  92   if (fork_ev == boost::asio::io_service::fork_child)
  93     interrupter_.recreate();
  94 }
  95
  96 void select_reactor::init_task()
  97 {
  98   io_service_.init_task();
  99 }
 100
 101 int select_reactor::register_descriptor(socket_type,
 102     select_reactor::per_descriptor_data&)
 103 {
 104   return 0;
 105 }
 106
 107 int select_reactor::register_internal_descriptor(
 108     int op_type, socket_type descriptor,
 109     select_reactor::per_descriptor_data&, reactor_op* op)
 110 {
 111   boost::asio::detail::mutex::scoped_lock lock(mutex_);
 112
 113   op_queue_[op_type].enqueue_operation(descriptor, op);
 114   interrupter_.interrupt();
 115
 116   return 0;
 117 }
 118
 119 void select_reactor::move_descriptor(socket_type,
 120     select_reactor::per_descriptor_data&,
 121     select_reactor::per_descriptor_data&)
 122 {
 123 }
 124
 125 void select_reactor::start_op(int op_type, socket_type descriptor,
 126     select_reactor::per_descriptor_data&, reactor_op* op,
 127     bool is_continuation, bool)
 128 {
 129   boost::asio::detail::mutex::scoped_lock lock(mutex_);
 130
 131   if (shutdown_)
 132   {
 133     post_immediate_completion(op, is_continuation);
 134     return;
 135   }
 136
 137   bool first = op_queue_[op_type].enqueue_operation(descriptor, op);
 138   io_service_.work_started();
 139   if (first)
 140     interrupter_.interrupt();
 141 }
 142
 143 void select_reactor::cancel_ops(socket_type descriptor,
 144     select_reactor::per_descriptor_data&)
 145 {
 146   boost::asio::detail::mutex::scoped_lock lock(mutex_);
 147   cancel_ops_unlocked(descriptor, boost::asio::error::operation_aborted);
 148 }
 149
 150 void select_reactor::deregister_descriptor(socket_type descriptor,
 151     select_reactor::per_descriptor_data&, bool)
 152 {
 153   boost::asio::detail::mutex::scoped_lock lock(mutex_);
 154   cancel_ops_unlocked(descriptor, boost::asio::error::operation_aborted);
 155 }
 156
 157 void select_reactor::deregister_internal_descriptor(
 158     socket_type descriptor, select_reactor::per_descriptor_data&)
 159 {
 160   boost::asio::detail::mutex::scoped_lock lock(mutex_);
 161   op_queue<operation> ops;
 162   for (int i = 0; i < max_ops; ++i)
 163     op_queue_[i].cancel_operations(descriptor, ops);
 164 }
 165
 166 void select_reactor::run(bool block, op_queue<operation>& ops)
 167 {
 168   boost::asio::detail::mutex::scoped_lock lock(mutex_);
 169
 170 #if defined(BOOST_ASIO_HAS_IOCP)
 171   // Check if the thread is supposed to stop.
 172   if (stop_thread_)
 173     return;
 174 #endif // defined(BOOST_ASIO_HAS_IOCP)
 175
 176   // Set up the descriptor sets.
 177   for (int i = 0; i < max_select_ops; ++i)
 178     fd_sets_[i].reset();
 179   fd_sets_[read_op].set(interrupter_.read_descriptor());
 180   socket_type max_fd = 0;
 181   bool have_work_to_do = !timer_queues_.all_empty();
 182   for (int i = 0; i < max_select_ops; ++i)
 183   {
 184     have_work_to_do = have_work_to_do || !op_queue_[i].empty();
 185     fd_sets_[i].set(op_queue_[i], ops);
 186     if (fd_sets_[i].max_descriptor() > max_fd)
 187       max_fd = fd_sets_[i].max_descriptor();
 188   }
 189
 190 #if defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
 191   // Connection operations on Windows use both except and write fd_sets.
 192   have_work_to_do = have_work_to_do || !op_queue_[connect_op].empty();
 193   fd_sets_[write_op].set(op_queue_[connect_op], ops);
 194   if (fd_sets_[write_op].max_descriptor() > max_fd)
 195     max_fd = fd_sets_[write_op].max_descriptor();
 196   fd_sets_[except_op].set(op_queue_[connect_op], ops);
 197   if (fd_sets_[except_op].max_descriptor() > max_fd)
 198     max_fd = fd_sets_[except_op].max_descriptor();
 199 #endif // defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
 200
 201   // We can return immediately if there's no work to do and the reactor is
 202   // not supposed to block.
 203   if (!block && !have_work_to_do)
 204     return;
 205
 206   // Determine how long to block while waiting for events.
 207   timeval tv_buf = { 0, 0 };
 208   timeval* tv = block ? get_timeout(tv_buf) : &tv_buf;
 209
 210   lock.unlock();
 211
 212   // Block on the select call until descriptors become ready.
 213   boost::system::error_code ec;
 214   int retval = socket_ops::select(static_cast<int>(max_fd + 1),
 215       fd_sets_[read_op], fd_sets_[write_op], fd_sets_[except_op], tv, ec);
 216
 217   // Reset the interrupter.
 218   if (retval > 0 && fd_sets_[read_op].is_set(interrupter_.read_descriptor()))
 219   {
 220     interrupter_.reset();
 221     --retval;
 222   }
 223
 224   lock.lock();
 225
 226   // Dispatch all ready operations.
 227   if (retval > 0)
 228   {
 229 #if defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
 230     // Connection operations on Windows use both except and write fd_sets.
 231     fd_sets_[except_op].perform(op_queue_[connect_op], ops);
 232     fd_sets_[write_op].perform(op_queue_[connect_op], ops);
 233 #endif // defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
 234
 235     // Exception operations must be processed first to ensure that any
 236     // out-of-band data is read before normal data.
 237     for (int i = max_select_ops - 1; i >= 0; --i)
 238       fd_sets_[i].perform(op_queue_[i], ops);
 239   }
 240   timer_queues_.get_ready_timers(ops);
 241 }
 242
 243 void select_reactor::interrupt()
 244 {
 245   interrupter_.interrupt();
 246 }
 247
 248 #if defined(BOOST_ASIO_HAS_IOCP)
 249 void select_reactor::run_thread()
 250 {
 251   boost::asio::detail::mutex::scoped_lock lock(mutex_);
 252   while (!stop_thread_)
 253   {
 254     lock.unlock();
 255     op_queue<operation> ops;
 256     run(true, ops);
 257     io_service_.post_deferred_completions(ops);
 258     lock.lock();
 259   }
 260 }
 261
 262 void select_reactor::call_run_thread(select_reactor* reactor)
 263 {
 264   reactor->run_thread();
 265 }
 266 #endif // defined(BOOST_ASIO_HAS_IOCP)
 267
 268 void select_reactor::do_add_timer_queue(timer_queue_base& queue)
 269 {
 270   mutex::scoped_lock lock(mutex_);
 271   timer_queues_.insert(&queue);
 272 }
 273
 274 void select_reactor::do_remove_timer_queue(timer_queue_base& queue)
 275 {
 276   mutex::scoped_lock lock(mutex_);
 277   timer_queues_.erase(&queue);
 278 }
 279
 280 timeval* select_reactor::get_timeout(timeval& tv)
 281 {
 282   // By default we will wait no longer than 5 minutes. This will ensure that
 283   // any changes to the system clock are detected after no longer than this.
 284   long usec = timer_queues_.wait_duration_usec(5 * 60 * 1000 * 1000);
 285   tv.tv_sec = usec / 1000000;
 286   tv.tv_usec = usec % 1000000;
 287   return &tv;
 288 }
 289
 290 void select_reactor::cancel_ops_unlocked(socket_type descriptor,
 291     const boost::system::error_code& ec)
 292 {
 293   bool need_interrupt = false;
 294   op_queue<operation> ops;
 295   for (int i = 0; i < max_ops; ++i)
 296     need_interrupt = op_queue_[i].cancel_operations(
 297         descriptor, ops, ec) || need_interrupt;
 298   io_service_.post_deferred_completions(ops);
 299   if (need_interrupt)
 300     interrupter_.interrupt();
 301 }
 302
 303 } // namespace detail
 304 } // namespace asio
 305 } // namespace boost
 306
 307 #include <boost/asio/detail/pop_options.hpp>
 308
 309 #endif // defined(BOOST_ASIO_HAS_IOCP)
 310        //   || (!defined(BOOST_ASIO_HAS_DEV_POLL)
 311        //       && !defined(BOOST_ASIO_HAS_EPOLL)
 312        //       && !defined(BOOST_ASIO_HAS_KQUEUE))
 313        //       && !defined(BOOST_ASIO_WINDOWS_RUNTIME))
 314
 315 #endif // BOOST_ASIO_DETAIL_IMPL_SELECT_REACTOR_IPP