ceph/src/boost/boost/asio/detail/dev_poll_reactor.hpp

   1 //
   2 // detail/dev_poll_reactor.hpp
   3 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2017 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_DEV_POLL_REACTOR_HPP
  12 #define BOOST_ASIO_DETAIL_DEV_POLL_REACTOR_HPP
  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_DEV_POLL)
  21
  22 #include <cstddef>
  23 #include <vector>
  24 #include <sys/devpoll.h>
  25 #include <boost/asio/detail/hash_map.hpp>
  26 #include <boost/asio/detail/limits.hpp>
  27 #include <boost/asio/detail/mutex.hpp>
  28 #include <boost/asio/detail/op_queue.hpp>
  29 #include <boost/asio/detail/reactor_op.hpp>
  30 #include <boost/asio/detail/reactor_op_queue.hpp>
  31 #include <boost/asio/detail/select_interrupter.hpp>
  32 #include <boost/asio/detail/socket_types.hpp>
  33 #include <boost/asio/detail/timer_queue_base.hpp>
  34 #include <boost/asio/detail/timer_queue_set.hpp>
  35 #include <boost/asio/detail/wait_op.hpp>
  36 #include <boost/asio/execution_context.hpp>
  37
  38 #include <boost/asio/detail/push_options.hpp>
  39
  40 namespace boost {
  41 namespace asio {
  42 namespace detail {
  43
  44 class dev_poll_reactor
  45   : public execution_context_service_base<dev_poll_reactor>
  46 {
  47 public:
  48   enum op_types { read_op = 0, write_op = 1,
  49     connect_op = 1, except_op = 2, max_ops = 3 };
  50
  51   // Per-descriptor data.
  52   struct per_descriptor_data
  53   {
  54   };
  55
  56   // Constructor.
  57   BOOST_ASIO_DECL dev_poll_reactor(boost::asio::execution_context& ctx);
  58
  59   // Destructor.
  60   BOOST_ASIO_DECL ~dev_poll_reactor();
  61
  62   // Destroy all user-defined handler objects owned by the service.
  63   BOOST_ASIO_DECL void shutdown();
  64
  65   // Recreate internal descriptors following a fork.
  66   BOOST_ASIO_DECL void notify_fork(
  67       boost::asio::execution_context::fork_event fork_ev);
  68
  69   // Initialise the task.
  70   BOOST_ASIO_DECL void init_task();
  71
  72   // Register a socket with the reactor. Returns 0 on success, system error
  73   // code on failure.
  74   BOOST_ASIO_DECL int register_descriptor(socket_type, per_descriptor_data&);
  75
  76   // Register a descriptor with an associated single operation. Returns 0 on
  77   // success, system error code on failure.
  78   BOOST_ASIO_DECL int register_internal_descriptor(
  79       int op_type, socket_type descriptor,
  80       per_descriptor_data& descriptor_data, reactor_op* op);
  81
  82   // Move descriptor registration from one descriptor_data object to another.
  83   BOOST_ASIO_DECL void move_descriptor(socket_type descriptor,
  84       per_descriptor_data& target_descriptor_data,
  85       per_descriptor_data& source_descriptor_data);
  86
  87   // Post a reactor operation for immediate completion.
  88   void post_immediate_completion(reactor_op* op, bool is_continuation)
  89   {
  90     scheduler_.post_immediate_completion(op, is_continuation);
  91   }
  92
  93   // Start a new operation. The reactor operation will be performed when the
  94   // given descriptor is flagged as ready, or an error has occurred.
  95   BOOST_ASIO_DECL void start_op(int op_type, socket_type descriptor,
  96       per_descriptor_data&, reactor_op* op,
  97       bool is_continuation, bool allow_speculative);
  98
  99   // Cancel all operations associated with the given descriptor. The
 100   // handlers associated with the descriptor will be invoked with the
 101   // operation_aborted error.
 102   BOOST_ASIO_DECL void cancel_ops(socket_type descriptor, per_descriptor_data&);
 103
 104   // Cancel any operations that are running against the descriptor and remove
 105   // its registration from the reactor. The reactor resources associated with
 106   // the descriptor must be released by calling cleanup_descriptor_data.
 107   BOOST_ASIO_DECL void deregister_descriptor(socket_type descriptor,
 108       per_descriptor_data&, bool closing);
 109
 110   // Remove the descriptor's registration from the reactor. The reactor
 111   // resources associated with the descriptor must be released by calling
 112   // cleanup_descriptor_data.
 113   BOOST_ASIO_DECL void deregister_internal_descriptor(
 114       socket_type descriptor, per_descriptor_data&);
 115
 116   // Perform any post-deregistration cleanup tasks associated with the
 117   // descriptor data.
 118   BOOST_ASIO_DECL void cleanup_descriptor_data(per_descriptor_data&);
 119
 120   // Add a new timer queue to the reactor.
 121   template <typename Time_Traits>
 122   void add_timer_queue(timer_queue<Time_Traits>& queue);
 123
 124   // Remove a timer queue from the reactor.
 125   template <typename Time_Traits>
 126   void remove_timer_queue(timer_queue<Time_Traits>& queue);
 127
 128   // Schedule a new operation in the given timer queue to expire at the
 129   // specified absolute time.
 130   template <typename Time_Traits>
 131   void schedule_timer(timer_queue<Time_Traits>& queue,
 132       const typename Time_Traits::time_type& time,
 133       typename timer_queue<Time_Traits>::per_timer_data& timer, wait_op* op);
 134
 135   // Cancel the timer operations associated with the given token. Returns the
 136   // number of operations that have been posted or dispatched.
 137   template <typename Time_Traits>
 138   std::size_t cancel_timer(timer_queue<Time_Traits>& queue,
 139       typename timer_queue<Time_Traits>::per_timer_data& timer,
 140       std::size_t max_cancelled = (std::numeric_limits<std::size_t>::max)());
 141
 142   // Move the timer operations associated with the given timer.
 143   template <typename Time_Traits>
 144   void move_timer(timer_queue<Time_Traits>& queue,
 145       typename timer_queue<Time_Traits>::per_timer_data& target,
 146       typename timer_queue<Time_Traits>::per_timer_data& source);
 147
 148   // Run /dev/poll once until interrupted or events are ready to be dispatched.
 149   BOOST_ASIO_DECL void run(long usec, op_queue<operation>& ops);
 150
 151   // Interrupt the select loop.
 152   BOOST_ASIO_DECL void interrupt();
 153
 154 private:
 155   // Create the /dev/poll file descriptor. Throws an exception if the descriptor
 156   // cannot be created.
 157   BOOST_ASIO_DECL static int do_dev_poll_create();
 158
 159   // Helper function to add a new timer queue.
 160   BOOST_ASIO_DECL void do_add_timer_queue(timer_queue_base& queue);
 161
 162   // Helper function to remove a timer queue.
 163   BOOST_ASIO_DECL void do_remove_timer_queue(timer_queue_base& queue);
 164
 165   // Get the timeout value for the /dev/poll DP_POLL operation. The timeout
 166   // value is returned as a number of milliseconds. A return value of -1
 167   // indicates that the poll should block indefinitely.
 168   BOOST_ASIO_DECL int get_timeout(int msec);
 169
 170   // Cancel all operations associated with the given descriptor. The do_cancel
 171   // function of the handler objects will be invoked. This function does not
 172   // acquire the dev_poll_reactor's mutex.
 173   BOOST_ASIO_DECL void cancel_ops_unlocked(socket_type descriptor,
 174       const boost::system::error_code& ec);
 175
 176   // Add a pending event entry for the given descriptor.
 177   BOOST_ASIO_DECL ::pollfd& add_pending_event_change(int descriptor);
 178
 179   // The scheduler implementation used to post completions.
 180   scheduler& scheduler_;
 181
 182   // Mutex to protect access to internal data.
 183   boost::asio::detail::mutex mutex_;
 184
 185   // The /dev/poll file descriptor.
 186   int dev_poll_fd_;
 187
 188   // Vector of /dev/poll events waiting to be written to the descriptor.
 189   std::vector< ::pollfd> pending_event_changes_;
 190
 191   // Hash map to associate a descriptor with a pending event change index.
 192   hash_map<int, std::size_t> pending_event_change_index_;
 193
 194   // The interrupter is used to break a blocking DP_POLL operation.
 195   select_interrupter interrupter_;
 196
 197   // The queues of read, write and except operations.
 198   reactor_op_queue<socket_type> op_queue_[max_ops];
 199
 200   // The timer queues.
 201   timer_queue_set timer_queues_;
 202
 203   // Whether the service has been shut down.
 204   bool shutdown_;
 205 };
 206
 207 } // namespace detail
 208 } // namespace asio
 209 } // namespace boost
 210
 211 #include <boost/asio/detail/pop_options.hpp>
 212
 213 #include <boost/asio/detail/impl/dev_poll_reactor.hpp>
 214 #if defined(BOOST_ASIO_HEADER_ONLY)
 215 # include <boost/asio/detail/impl/dev_poll_reactor.ipp>
 216 #endif // defined(BOOST_ASIO_HEADER_ONLY)
 217
 218 #endif // defined(BOOST_ASIO_HAS_DEV_POLL)
 219
 220 #endif // BOOST_ASIO_DETAIL_DEV_POLL_REACTOR_HPP