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Diffstat (limited to 'lib/asio/detail/epoll_reactor.hpp')
-rw-r--r-- | lib/asio/detail/epoll_reactor.hpp | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/lib/asio/detail/epoll_reactor.hpp b/lib/asio/detail/epoll_reactor.hpp new file mode 100644 index 0000000..5f58109 --- /dev/null +++ b/lib/asio/detail/epoll_reactor.hpp @@ -0,0 +1,266 @@ +// +// detail/epoll_reactor.hpp +// ~~~~~~~~~~~~~~~~~~~~~~~~ +// +// Copyright (c) 2003-2018 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 ASIO_DETAIL_EPOLL_REACTOR_HPP +#define ASIO_DETAIL_EPOLL_REACTOR_HPP + +#if defined(_MSC_VER) && (_MSC_VER >= 1200) +# pragma once +#endif // defined(_MSC_VER) && (_MSC_VER >= 1200) + +#include "asio/detail/config.hpp" + +#if defined(ASIO_HAS_EPOLL) + +#include "asio/detail/atomic_count.hpp" +#include "asio/detail/conditionally_enabled_mutex.hpp" +#include "asio/detail/limits.hpp" +#include "asio/detail/object_pool.hpp" +#include "asio/detail/op_queue.hpp" +#include "asio/detail/reactor_op.hpp" +#include "asio/detail/select_interrupter.hpp" +#include "asio/detail/socket_types.hpp" +#include "asio/detail/timer_queue_base.hpp" +#include "asio/detail/timer_queue_set.hpp" +#include "asio/detail/wait_op.hpp" +#include "asio/execution_context.hpp" + +#if defined(ASIO_HAS_TIMERFD) +# include <sys/timerfd.h> +#endif // defined(ASIO_HAS_TIMERFD) + +#include "asio/detail/push_options.hpp" + +namespace asio { +namespace detail { + +class epoll_reactor + : public execution_context_service_base<epoll_reactor> +{ +private: + // The mutex type used by this reactor. + typedef conditionally_enabled_mutex mutex; + +public: + enum op_types { read_op = 0, write_op = 1, + connect_op = 1, except_op = 2, max_ops = 3 }; + + // Per-descriptor queues. + class descriptor_state : operation + { + friend class epoll_reactor; + friend class object_pool_access; + + descriptor_state* next_; + descriptor_state* prev_; + + mutex mutex_; + epoll_reactor* reactor_; + int descriptor_; + uint32_t registered_events_; + op_queue<reactor_op> op_queue_[max_ops]; + bool try_speculative_[max_ops]; + bool shutdown_; + + ASIO_DECL descriptor_state(bool locking); + void set_ready_events(uint32_t events) { task_result_ = events; } + void add_ready_events(uint32_t events) { task_result_ |= events; } + ASIO_DECL operation* perform_io(uint32_t events); + ASIO_DECL static void do_complete( + void* owner, operation* base, + const asio::error_code& ec, std::size_t bytes_transferred); + }; + + // Per-descriptor data. + typedef descriptor_state* per_descriptor_data; + + // Constructor. + ASIO_DECL epoll_reactor(asio::execution_context& ctx); + + // Destructor. + ASIO_DECL ~epoll_reactor(); + + // Destroy all user-defined handler objects owned by the service. + ASIO_DECL void shutdown(); + + // Recreate internal descriptors following a fork. + ASIO_DECL void notify_fork( + asio::execution_context::fork_event fork_ev); + + // Initialise the task. + ASIO_DECL void init_task(); + + // Register a socket with the reactor. Returns 0 on success, system error + // code on failure. + ASIO_DECL int register_descriptor(socket_type descriptor, + per_descriptor_data& descriptor_data); + + // Register a descriptor with an associated single operation. Returns 0 on + // success, system error code on failure. + ASIO_DECL int register_internal_descriptor( + int op_type, socket_type descriptor, + per_descriptor_data& descriptor_data, reactor_op* op); + + // Move descriptor registration from one descriptor_data object to another. + ASIO_DECL void move_descriptor(socket_type descriptor, + per_descriptor_data& target_descriptor_data, + per_descriptor_data& source_descriptor_data); + + // Post a reactor operation for immediate completion. + void post_immediate_completion(reactor_op* op, bool is_continuation) + { + scheduler_.post_immediate_completion(op, is_continuation); + } + + // Start a new operation. The reactor operation will be performed when the + // given descriptor is flagged as ready, or an error has occurred. + ASIO_DECL void start_op(int op_type, socket_type descriptor, + per_descriptor_data& descriptor_data, reactor_op* op, + bool is_continuation, bool allow_speculative); + + // Cancel all operations associated with the given descriptor. The + // handlers associated with the descriptor will be invoked with the + // operation_aborted error. + ASIO_DECL void cancel_ops(socket_type descriptor, + per_descriptor_data& descriptor_data); + + // Cancel any operations that are running against the descriptor and remove + // its registration from the reactor. The reactor resources associated with + // the descriptor must be released by calling cleanup_descriptor_data. + ASIO_DECL void deregister_descriptor(socket_type descriptor, + per_descriptor_data& descriptor_data, bool closing); + + // Remove the descriptor's registration from the reactor. The reactor + // resources associated with the descriptor must be released by calling + // cleanup_descriptor_data. + ASIO_DECL void deregister_internal_descriptor( + socket_type descriptor, per_descriptor_data& descriptor_data); + + // Perform any post-deregistration cleanup tasks associated with the + // descriptor data. + ASIO_DECL void cleanup_descriptor_data( + per_descriptor_data& descriptor_data); + + // Add a new timer queue to the reactor. + template <typename Time_Traits> + void add_timer_queue(timer_queue<Time_Traits>& timer_queue); + + // Remove a timer queue from the reactor. + template <typename Time_Traits> + void remove_timer_queue(timer_queue<Time_Traits>& timer_queue); + + // Schedule a new operation in the given timer queue to expire at the + // specified absolute time. + template <typename Time_Traits> + void schedule_timer(timer_queue<Time_Traits>& queue, + const typename Time_Traits::time_type& time, + typename timer_queue<Time_Traits>::per_timer_data& timer, wait_op* op); + + // Cancel the timer operations associated with the given token. Returns the + // number of operations that have been posted or dispatched. + template <typename Time_Traits> + std::size_t cancel_timer(timer_queue<Time_Traits>& queue, + typename timer_queue<Time_Traits>::per_timer_data& timer, + std::size_t max_cancelled = (std::numeric_limits<std::size_t>::max)()); + + // Move the timer operations associated with the given timer. + template <typename Time_Traits> + void move_timer(timer_queue<Time_Traits>& queue, + typename timer_queue<Time_Traits>::per_timer_data& target, + typename timer_queue<Time_Traits>::per_timer_data& source); + + // Run epoll once until interrupted or events are ready to be dispatched. + ASIO_DECL void run(long usec, op_queue<operation>& ops); + + // Interrupt the select loop. + ASIO_DECL void interrupt(); + +private: + // The hint to pass to epoll_create to size its data structures. + enum { epoll_size = 20000 }; + + // Create the epoll file descriptor. Throws an exception if the descriptor + // cannot be created. + ASIO_DECL static int do_epoll_create(); + + // Create the timerfd file descriptor. Does not throw. + ASIO_DECL static int do_timerfd_create(); + + // Allocate a new descriptor state object. + ASIO_DECL descriptor_state* allocate_descriptor_state(); + + // Free an existing descriptor state object. + ASIO_DECL void free_descriptor_state(descriptor_state* s); + + // Helper function to add a new timer queue. + ASIO_DECL void do_add_timer_queue(timer_queue_base& queue); + + // Helper function to remove a timer queue. + ASIO_DECL void do_remove_timer_queue(timer_queue_base& queue); + + // Called to recalculate and update the timeout. + ASIO_DECL void update_timeout(); + + // Get the timeout value for the epoll_wait call. The timeout value is + // returned as a number of milliseconds. A return value of -1 indicates + // that epoll_wait should block indefinitely. + ASIO_DECL int get_timeout(int msec); + +#if defined(ASIO_HAS_TIMERFD) + // Get the timeout value for the timer descriptor. The return value is the + // flag argument to be used when calling timerfd_settime. + ASIO_DECL int get_timeout(itimerspec& ts); +#endif // defined(ASIO_HAS_TIMERFD) + + // The scheduler implementation used to post completions. + scheduler& scheduler_; + + // Mutex to protect access to internal data. + mutex mutex_; + + // The interrupter is used to break a blocking epoll_wait call. + select_interrupter interrupter_; + + // The epoll file descriptor. + int epoll_fd_; + + // The timer file descriptor. + int timer_fd_; + + // The timer queues. + timer_queue_set timer_queues_; + + // Whether the service has been shut down. + bool shutdown_; + + // Mutex to protect access to the registered descriptors. + mutex registered_descriptors_mutex_; + + // Keep track of all registered descriptors. + object_pool<descriptor_state> registered_descriptors_; + + // Helper class to do post-perform_io cleanup. + struct perform_io_cleanup_on_block_exit; + friend struct perform_io_cleanup_on_block_exit; +}; + +} // namespace detail +} // namespace asio + +#include "asio/detail/pop_options.hpp" + +#include "asio/detail/impl/epoll_reactor.hpp" +#if defined(ASIO_HEADER_ONLY) +# include "asio/detail/impl/epoll_reactor.ipp" +#endif // defined(ASIO_HEADER_ONLY) + +#endif // defined(ASIO_HAS_EPOLL) + +#endif // ASIO_DETAIL_EPOLL_REACTOR_HPP |