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1 //
2 // detail/select_reactor.hpp
3 // ~~~~~~~~~~~~~~~~~~~~~~~~~
4 //
5 // Copyright (c) 2003-2015 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 ASIO_DETAIL_SELECT_REACTOR_HPP
12 #define ASIO_DETAIL_SELECT_REACTOR_HPP
13 
14 
15 #include "asio/detail/config.hpp"
16 
17 #if defined(ASIO_HAS_IOCP)    || (!defined(ASIO_HAS_DEV_POLL)        && !defined(ASIO_HAS_EPOLL)        && !defined(ASIO_HAS_KQUEUE)        && !defined(ASIO_WINDOWS_RUNTIME))
18 
19 #include <cstddef>
20 #include "asio/detail/fd_set_adapter.hpp"
21 #include "asio/detail/limits.hpp"
22 #include "asio/detail/mutex.hpp"
23 #include "asio/detail/op_queue.hpp"
24 #include "asio/detail/reactor_op.hpp"
25 #include "asio/detail/reactor_op_queue.hpp"
26 #include "asio/detail/select_interrupter.hpp"
27 #include "asio/detail/socket_types.hpp"
28 #include "asio/detail/timer_queue_base.hpp"
29 #include "asio/detail/timer_queue_set.hpp"
30 #include "asio/detail/wait_op.hpp"
31 #include "asio/io_service.hpp"
32 
33 
34 #include "asio/detail/push_options.hpp"
35 
36 namespace asio {
37 namespace detail {
38 
39 class select_reactor
40   : public asio::detail::service_base<select_reactor>
41 {
42 public:
43   enum op_types { read_op = 0, write_op = 1, except_op = 2,
44     max_select_ops = 3, connect_op = 1, max_ops = 3 };
45 
46   // Per-descriptor data.
47   struct per_descriptor_data
48   {
49   };
50 
51   // Constructor.
52   ASIO_DECL select_reactor(asio::io_service& io_service);
53 
54   // Destructor.
55   ASIO_DECL ~select_reactor();
56 
57   // Destroy all user-defined handler objects owned by the service.
58   ASIO_DECL void shutdown_service();
59 
60   // Recreate internal descriptors following a fork.
61   ASIO_DECL void fork_service(
62       asio::io_service::fork_event fork_ev);
63 
64   // Initialise the task, but only if the reactor is not in its own thread.
65   ASIO_DECL void init_task();
66 
67   // Register a socket with the reactor. Returns 0 on success, system error
68   // code on failure.
69   ASIO_DECL int register_descriptor(socket_type, per_descriptor_data&);
70 
71   // Register a descriptor with an associated single operation. Returns 0 on
72   // success, system error code on failure.
73   ASIO_DECL int register_internal_descriptor(
74       int op_type, socket_type descriptor,
75       per_descriptor_data& descriptor_data, reactor_op* op);
76 
77   // Post a reactor operation for immediate completion.
post_immediate_completion(reactor_op * op,bool is_continuation)78   void post_immediate_completion(reactor_op* op, bool is_continuation)
79   {
80     io_service_.post_immediate_completion(op, is_continuation);
81   }
82 
83   // Start a new operation. The reactor operation will be performed when the
84   // given descriptor is flagged as ready, or an error has occurred.
85   ASIO_DECL void start_op(int op_type, socket_type descriptor,
86       per_descriptor_data&, reactor_op* op, bool is_continuation, bool);
87 
88   // Cancel all operations associated with the given descriptor. The
89   // handlers associated with the descriptor will be invoked with the
90   // operation_aborted error.
91   ASIO_DECL void cancel_ops(socket_type descriptor, per_descriptor_data&);
92 
93   // Cancel any operations that are running against the descriptor and remove
94   // its registration from the reactor.
95   ASIO_DECL void deregister_descriptor(socket_type descriptor,
96       per_descriptor_data&, bool closing);
97 
98   // Remote the descriptor's registration from the reactor.
99   ASIO_DECL void deregister_internal_descriptor(
100       socket_type descriptor, per_descriptor_data& descriptor_data);
101 
102   // Move descriptor registration from one descriptor_data object to another.
103   ASIO_DECL void move_descriptor(socket_type descriptor,
104       per_descriptor_data& target_descriptor_data,
105       per_descriptor_data& source_descriptor_data);
106 
107   // Add a new timer queue to the reactor.
108   template <typename Time_Traits>
109   void add_timer_queue(timer_queue<Time_Traits>& queue);
110 
111   // Remove a timer queue from the reactor.
112   template <typename Time_Traits>
113   void remove_timer_queue(timer_queue<Time_Traits>& queue);
114 
115   // Schedule a new operation in the given timer queue to expire at the
116   // specified absolute time.
117   template <typename Time_Traits>
118   void schedule_timer(timer_queue<Time_Traits>& queue,
119       const typename Time_Traits::time_type& time,
120       typename timer_queue<Time_Traits>::per_timer_data& timer, wait_op* op);
121 
122   // Cancel the timer operations associated with the given token. Returns the
123   // number of operations that have been posted or dispatched.
124   template <typename Time_Traits>
125   std::size_t cancel_timer(timer_queue<Time_Traits>& queue,
126       typename timer_queue<Time_Traits>::per_timer_data& timer,
127       std::size_t max_cancelled = (std::numeric_limits<std::size_t>::max)());
128 
129   // Run select once until interrupted or events are ready to be dispatched.
130   ASIO_DECL void run(bool block, op_queue<operation>& ops);
131 
132   // Interrupt the select loop.
133   ASIO_DECL void interrupt();
134 
135 private:
136 
137   // Helper function to add a new timer queue.
138   ASIO_DECL void do_add_timer_queue(timer_queue_base& queue);
139 
140   // Helper function to remove a timer queue.
141   ASIO_DECL void do_remove_timer_queue(timer_queue_base& queue);
142 
143   // Get the timeout value for the select call.
144   ASIO_DECL timeval* get_timeout(timeval& tv);
145 
146   // Cancel all operations associated with the given descriptor. This function
147   // does not acquire the select_reactor's mutex.
148   ASIO_DECL void cancel_ops_unlocked(socket_type descriptor,
149       const asio::error_code& ec);
150 
151   // The io_service implementation used to post completions.
152   io_service_impl& io_service_;
153 
154   // Mutex to protect access to internal data.
155   asio::detail::mutex mutex_;
156 
157   // The interrupter is used to break a blocking select call.
158   select_interrupter interrupter_;
159 
160   // The queues of read, write and except operations.
161   reactor_op_queue<socket_type> op_queue_[max_ops];
162 
163   // The file descriptor sets to be passed to the select system call.
164   fd_set_adapter fd_sets_[max_select_ops];
165 
166   // The timer queues.
167   timer_queue_set timer_queues_;
168 
169 
170   // Whether the service has been shut down.
171   bool shutdown_;
172 };
173 
174 } // namespace detail
175 } // namespace asio
176 
177 #include "asio/detail/pop_options.hpp"
178 
179 #include "asio/detail/impl/select_reactor.hpp"
180 # include "asio/detail/impl/select_reactor.ipp"
181 
182 #endif // defined(ASIO_HAS_IOCP)
183        //   || (!defined(ASIO_HAS_DEV_POLL)
184        //       && !defined(ASIO_HAS_EPOLL)
185        //       && !defined(ASIO_HAS_KQUEUE)
186        //       && !defined(ASIO_WINDOWS_RUNTIME))
187 
188 #endif // ASIO_DETAIL_SELECT_REACTOR_HPP
189