1 | // |
2 | // detail/epoll_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 BOOST_ASIO_DETAIL_EPOLL_REACTOR_HPP |
12 | #define BOOST_ASIO_DETAIL_EPOLL_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_EPOLL) |
21 | |
22 | #include <boost/asio/io_service.hpp> |
23 | #include <boost/asio/detail/atomic_count.hpp> |
24 | #include <boost/asio/detail/limits.hpp> |
25 | #include <boost/asio/detail/mutex.hpp> |
26 | #include <boost/asio/detail/object_pool.hpp> |
27 | #include <boost/asio/detail/op_queue.hpp> |
28 | #include <boost/asio/detail/reactor_op.hpp> |
29 | #include <boost/asio/detail/select_interrupter.hpp> |
30 | #include <boost/asio/detail/socket_types.hpp> |
31 | #include <boost/asio/detail/timer_queue_base.hpp> |
32 | #include <boost/asio/detail/timer_queue_set.hpp> |
33 | #include <boost/asio/detail/wait_op.hpp> |
34 | |
35 | #include <boost/asio/detail/push_options.hpp> |
36 | |
37 | namespace boost { |
38 | namespace asio { |
39 | namespace detail { |
40 | |
41 | class epoll_reactor |
42 | : public boost::asio::detail::service_base<epoll_reactor> |
43 | { |
44 | public: |
45 | enum op_types { read_op = 0, write_op = 1, |
46 | connect_op = 1, except_op = 2, max_ops = 3 }; |
47 | |
48 | // Per-descriptor queues. |
49 | class descriptor_state : operation |
50 | { |
51 | friend class epoll_reactor; |
52 | friend class object_pool_access; |
53 | |
54 | descriptor_state* next_; |
55 | descriptor_state* prev_; |
56 | |
57 | mutex mutex_; |
58 | epoll_reactor* reactor_; |
59 | int descriptor_; |
60 | uint32_t registered_events_; |
61 | op_queue<reactor_op> op_queue_[max_ops]; |
62 | bool shutdown_; |
63 | |
64 | BOOST_ASIO_DECL descriptor_state(); |
65 | void set_ready_events(uint32_t events) { task_result_ = events; } |
66 | BOOST_ASIO_DECL operation* perform_io(uint32_t events); |
67 | BOOST_ASIO_DECL static void do_complete( |
68 | io_service_impl* owner, operation* base, |
69 | const boost::system::error_code& ec, std::size_t bytes_transferred); |
70 | }; |
71 | |
72 | // Per-descriptor data. |
73 | typedef descriptor_state* per_descriptor_data; |
74 | |
75 | // Constructor. |
76 | BOOST_ASIO_DECL epoll_reactor(boost::asio::io_service& io_service); |
77 | |
78 | // Destructor. |
79 | BOOST_ASIO_DECL ~epoll_reactor(); |
80 | |
81 | // Destroy all user-defined handler objects owned by the service. |
82 | BOOST_ASIO_DECL void shutdown_service(); |
83 | |
84 | // Recreate internal descriptors following a fork. |
85 | BOOST_ASIO_DECL void fork_service( |
86 | boost::asio::io_service::fork_event fork_ev); |
87 | |
88 | // Initialise the task. |
89 | BOOST_ASIO_DECL void init_task(); |
90 | |
91 | // Register a socket with the reactor. Returns 0 on success, system error |
92 | // code on failure. |
93 | BOOST_ASIO_DECL int register_descriptor(socket_type descriptor, |
94 | per_descriptor_data& descriptor_data); |
95 | |
96 | // Register a descriptor with an associated single operation. Returns 0 on |
97 | // success, system error code on failure. |
98 | BOOST_ASIO_DECL int register_internal_descriptor( |
99 | int op_type, socket_type descriptor, |
100 | per_descriptor_data& descriptor_data, reactor_op* op); |
101 | |
102 | // Move descriptor registration from one descriptor_data object to another. |
103 | BOOST_ASIO_DECL void move_descriptor(socket_type descriptor, |
104 | per_descriptor_data& target_descriptor_data, |
105 | per_descriptor_data& source_descriptor_data); |
106 | |
107 | // Post a reactor operation for immediate completion. |
108 | void post_immediate_completion(reactor_op* op, bool is_continuation) |
109 | { |
110 | io_service_.post_immediate_completion(op, is_continuation); |
111 | } |
112 | |
113 | // Start a new operation. The reactor operation will be performed when the |
114 | // given descriptor is flagged as ready, or an error has occurred. |
115 | BOOST_ASIO_DECL void start_op(int op_type, socket_type descriptor, |
116 | per_descriptor_data& descriptor_data, reactor_op* op, |
117 | bool is_continuation, bool allow_speculative); |
118 | |
119 | // Cancel all operations associated with the given descriptor. The |
120 | // handlers associated with the descriptor will be invoked with the |
121 | // operation_aborted error. |
122 | BOOST_ASIO_DECL void cancel_ops(socket_type descriptor, |
123 | per_descriptor_data& descriptor_data); |
124 | |
125 | // Cancel any operations that are running against the descriptor and remove |
126 | // its registration from the reactor. |
127 | BOOST_ASIO_DECL void deregister_descriptor(socket_type descriptor, |
128 | per_descriptor_data& descriptor_data, bool closing); |
129 | |
130 | // Remote the descriptor's registration from the reactor. |
131 | BOOST_ASIO_DECL void deregister_internal_descriptor( |
132 | socket_type descriptor, per_descriptor_data& descriptor_data); |
133 | |
134 | // Add a new timer queue to the reactor. |
135 | template <typename Time_Traits> |
136 | void add_timer_queue(timer_queue<Time_Traits>& timer_queue); |
137 | |
138 | // Remove a timer queue from the reactor. |
139 | template <typename Time_Traits> |
140 | void remove_timer_queue(timer_queue<Time_Traits>& timer_queue); |
141 | |
142 | // Schedule a new operation in the given timer queue to expire at the |
143 | // specified absolute time. |
144 | template <typename Time_Traits> |
145 | void schedule_timer(timer_queue<Time_Traits>& queue, |
146 | const typename Time_Traits::time_type& time, |
147 | typename timer_queue<Time_Traits>::per_timer_data& timer, wait_op* op); |
148 | |
149 | // Cancel the timer operations associated with the given token. Returns the |
150 | // number of operations that have been posted or dispatched. |
151 | template <typename Time_Traits> |
152 | std::size_t cancel_timer(timer_queue<Time_Traits>& queue, |
153 | typename timer_queue<Time_Traits>::per_timer_data& timer, |
154 | std::size_t max_cancelled = (std::numeric_limits<std::size_t>::max)()); |
155 | |
156 | // Run epoll once until interrupted or events are ready to be dispatched. |
157 | BOOST_ASIO_DECL void run(bool block, op_queue<operation>& ops); |
158 | |
159 | // Interrupt the select loop. |
160 | BOOST_ASIO_DECL void interrupt(); |
161 | |
162 | private: |
163 | // The hint to pass to epoll_create to size its data structures. |
164 | enum { epoll_size = 20000 }; |
165 | |
166 | // Create the epoll file descriptor. Throws an exception if the descriptor |
167 | // cannot be created. |
168 | BOOST_ASIO_DECL static int do_epoll_create(); |
169 | |
170 | // Create the timerfd file descriptor. Does not throw. |
171 | BOOST_ASIO_DECL static int do_timerfd_create(); |
172 | |
173 | // Allocate a new descriptor state object. |
174 | BOOST_ASIO_DECL descriptor_state* allocate_descriptor_state(); |
175 | |
176 | // Free an existing descriptor state object. |
177 | BOOST_ASIO_DECL void free_descriptor_state(descriptor_state* s); |
178 | |
179 | // Helper function to add a new timer queue. |
180 | BOOST_ASIO_DECL void do_add_timer_queue(timer_queue_base& queue); |
181 | |
182 | // Helper function to remove a timer queue. |
183 | BOOST_ASIO_DECL void do_remove_timer_queue(timer_queue_base& queue); |
184 | |
185 | // Called to recalculate and update the timeout. |
186 | BOOST_ASIO_DECL void update_timeout(); |
187 | |
188 | // Get the timeout value for the epoll_wait call. The timeout value is |
189 | // returned as a number of milliseconds. A return value of -1 indicates |
190 | // that epoll_wait should block indefinitely. |
191 | BOOST_ASIO_DECL int get_timeout(); |
192 | |
193 | #if defined(BOOST_ASIO_HAS_TIMERFD) |
194 | // Get the timeout value for the timer descriptor. The return value is the |
195 | // flag argument to be used when calling timerfd_settime. |
196 | BOOST_ASIO_DECL int get_timeout(itimerspec& ts); |
197 | #endif // defined(BOOST_ASIO_HAS_TIMERFD) |
198 | |
199 | // The io_service implementation used to post completions. |
200 | io_service_impl& io_service_; |
201 | |
202 | // Mutex to protect access to internal data. |
203 | mutex mutex_; |
204 | |
205 | // The interrupter is used to break a blocking epoll_wait call. |
206 | select_interrupter interrupter_; |
207 | |
208 | // The epoll file descriptor. |
209 | int epoll_fd_; |
210 | |
211 | // The timer file descriptor. |
212 | int timer_fd_; |
213 | |
214 | // The timer queues. |
215 | timer_queue_set timer_queues_; |
216 | |
217 | // Whether the service has been shut down. |
218 | bool shutdown_; |
219 | |
220 | // Mutex to protect access to the registered descriptors. |
221 | mutex registered_descriptors_mutex_; |
222 | |
223 | // Keep track of all registered descriptors. |
224 | object_pool<descriptor_state> registered_descriptors_; |
225 | |
226 | // Helper class to do post-perform_io cleanup. |
227 | struct perform_io_cleanup_on_block_exit; |
228 | friend struct perform_io_cleanup_on_block_exit; |
229 | }; |
230 | |
231 | } // namespace detail |
232 | } // namespace asio |
233 | } // namespace boost |
234 | |
235 | #include <boost/asio/detail/pop_options.hpp> |
236 | |
237 | #include <boost/asio/detail/impl/epoll_reactor.hpp> |
238 | #if defined(BOOST_ASIO_HEADER_ONLY) |
239 | # include <boost/asio/detail/impl/epoll_reactor.ipp> |
240 | #endif // defined(BOOST_ASIO_HEADER_ONLY) |
241 | |
242 | #endif // defined(BOOST_ASIO_HAS_EPOLL) |
243 | |
244 | #endif // BOOST_ASIO_DETAIL_EPOLL_REACTOR_HPP |
245 | |