| // |
| // detail/io_uring_service.hpp |
| // ~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| // |
| // Copyright (c) 2003-2021 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_IO_URING_SERVICE_HPP |
| #define ASIO_DETAIL_IO_URING_SERVICE_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_IO_URING) |
| |
| #include <liburing.h> |
| #include "asio/detail/atomic_count.hpp" |
| #include "asio/detail/buffer_sequence_adapter.hpp" |
| #include "asio/detail/conditionally_enabled_mutex.hpp" |
| #include "asio/detail/io_uring_operation.hpp" |
| #include "asio/detail/limits.hpp" |
| #include "asio/detail/object_pool.hpp" |
| #include "asio/detail/op_queue.hpp" |
| #include "asio/detail/scheduler.hpp" |
| #include "asio/detail/scheduler_task.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" |
| |
| #include "asio/detail/push_options.hpp" |
| |
| namespace asio { |
| namespace detail { |
| |
| class io_uring_service |
| : public execution_context_service_base<io_uring_service>, |
| public scheduler_task |
| { |
| private: |
| // The mutex type used by this reactor. |
| typedef conditionally_enabled_mutex mutex; |
| |
| public: |
| enum op_types { read_op = 0, write_op = 1, except_op = 2, max_ops = 3 }; |
| |
| class io_object; |
| |
| // An I/O queue stores operations that must run serially. |
| class io_queue : operation |
| { |
| friend class io_uring_service; |
| |
| io_object* io_object_; |
| op_queue<io_uring_operation> op_queue_; |
| bool cancel_requested_; |
| |
| ASIO_DECL io_queue(); |
| void set_result(int r) { task_result_ = static_cast<unsigned>(r); } |
| ASIO_DECL operation* perform_io(int result); |
| ASIO_DECL static void do_complete(void* owner, operation* base, |
| const asio::error_code& ec, std::size_t bytes_transferred); |
| }; |
| |
| // Per I/O object state. |
| class io_object |
| { |
| friend class io_uring_service; |
| friend class object_pool_access; |
| |
| io_object* next_; |
| io_object* prev_; |
| |
| mutex mutex_; |
| io_uring_service* service_; |
| io_queue queues_[max_ops]; |
| bool shutdown_; |
| |
| ASIO_DECL io_object(bool locking); |
| }; |
| |
| // Per I/O object data. |
| typedef io_object* per_io_object_data; |
| |
| // Constructor. |
| ASIO_DECL io_uring_service(asio::execution_context& ctx); |
| |
| // Destructor. |
| ASIO_DECL ~io_uring_service(); |
| |
| // Destroy all user-defined handler objects owned by the service. |
| ASIO_DECL void shutdown(); |
| |
| // Recreate internal state following a fork. |
| ASIO_DECL void notify_fork( |
| asio::execution_context::fork_event fork_ev); |
| |
| // Initialise the task. |
| ASIO_DECL void init_task(); |
| |
| // Register an I/O object with io_uring. |
| ASIO_DECL void register_io_object(io_object*& io_obj); |
| |
| // Register an internal I/O object with io_uring. |
| ASIO_DECL void register_internal_io_object( |
| io_object*& io_obj, int op_type, io_uring_operation* op); |
| |
| // Register buffers with io_uring. |
| ASIO_DECL void register_buffers(const ::iovec* v, unsigned n); |
| |
| // Unregister buffers from io_uring. |
| ASIO_DECL void unregister_buffers(); |
| |
| // Post an operation for immediate completion. |
| void post_immediate_completion(operation* op, bool is_continuation); |
| |
| // Start a new operation. The operation will be prepared and submitted to the |
| // io_uring when it is at the head of its I/O operation queue. |
| ASIO_DECL void start_op(int op_type, per_io_object_data& io_obj, |
| io_uring_operation* op, bool is_continuation); |
| |
| // Cancel all operations associated with the given I/O object. The handlers |
| // associated with the I/O object will be invoked with the operation_aborted |
| // error. |
| ASIO_DECL void cancel_ops(per_io_object_data& io_obj); |
| |
| // Cancel all operations associated with the given I/O object and key. The |
| // handlers associated with the object and key will be invoked with the |
| // operation_aborted error. |
| ASIO_DECL void cancel_ops_by_key(per_io_object_data& io_obj, |
| int op_type, void* cancellation_key); |
| |
| // Cancel any operations that are running against the I/O object and remove |
| // its registration from the service. The service resources associated with |
| // the I/O object must be released by calling cleanup_io_object. |
| ASIO_DECL void deregister_io_object(per_io_object_data& io_obj); |
| |
| // Perform any post-deregistration cleanup tasks associated with the I/O |
| // object. |
| ASIO_DECL void cleanup_io_object(per_io_object_data& io_obj); |
| |
| // 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)()); |
| |
| // Cancel the timer operations associated with the given key. |
| template <typename Time_Traits> |
| void cancel_timer_by_key(timer_queue<Time_Traits>& queue, |
| typename timer_queue<Time_Traits>::per_timer_data* timer, |
| void* cancellation_key); |
| |
| // 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); |
| |
| // Wait on io_uring once until interrupted or events are ready to be |
| // dispatched. |
| ASIO_DECL void run(long usec, op_queue<operation>& ops); |
| |
| // Interrupt the io_uring wait. |
| ASIO_DECL void interrupt(); |
| |
| private: |
| // The hint to pass to io_uring_queue_init to size its data structures. |
| enum { ring_size = 16384 }; |
| |
| // The number of operations to submit in a batch. |
| enum { submit_batch_size = 128 }; |
| |
| // The number of operations to complete in a batch. |
| enum { complete_batch_size = 128 }; |
| |
| // The type used for processing eventfd readiness notifications. |
| class event_fd_read_op; |
| |
| // Initialise the ring. |
| ASIO_DECL void init_ring(); |
| |
| // Register the eventfd descriptor for readiness notifications. |
| ASIO_DECL void register_with_reactor(); |
| |
| // Allocate a new I/O object. |
| ASIO_DECL io_object* allocate_io_object(); |
| |
| // Free an existing I/O object. |
| ASIO_DECL void free_io_object(io_object* s); |
| |
| // Helper function to cancel all operations associated with the given I/O |
| // object. This function does not acquire the I/O object's mutex. |
| ASIO_DECL void do_cancel_ops( |
| per_io_object_data& io_obj, op_queue<operation>& ops); |
| |
| // 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 current timeout value. |
| ASIO_DECL __kernel_timespec get_timeout() const; |
| |
| // Get a new submission queue entry, flushing the queue if necessary. |
| ASIO_DECL ::io_uring_sqe* get_sqe(); |
| |
| // Submit pending submission queue entries. |
| ASIO_DECL void submit_sqes(); |
| |
| // Post an operation to submit the pending submission queue entries. |
| ASIO_DECL void post_submit_sqes_op(mutex::scoped_lock& lock); |
| |
| // Push an operation to submit the pending submission queue entries. |
| ASIO_DECL void push_submit_sqes_op(op_queue<operation>& ops); |
| |
| // Helper operation to submit pending submission queue entries. |
| class submit_sqes_op : operation |
| { |
| friend class io_uring_service; |
| |
| io_uring_service* service_; |
| |
| ASIO_DECL submit_sqes_op(io_uring_service* s); |
| ASIO_DECL static void do_complete(void* owner, operation* base, |
| const asio::error_code& ec, std::size_t bytes_transferred); |
| }; |
| |
| // The scheduler implementation used to post completions. |
| scheduler& scheduler_; |
| |
| // Mutex to protect access to internal data. |
| mutex mutex_; |
| |
| // The ring. |
| ::io_uring ring_; |
| |
| // The count of unfinished work. |
| atomic_count outstanding_work_; |
| |
| // The operation used to submit the pending submission queue entries. |
| submit_sqes_op submit_sqes_op_; |
| |
| // The number of pending submission queue entries_. |
| int pending_sqes_; |
| |
| // Whether there is a pending submission operation. |
| bool pending_submit_sqes_op_; |
| |
| // Whether the service has been shut down. |
| bool shutdown_; |
| |
| // The timer queues. |
| timer_queue_set timer_queues_; |
| |
| // The timespec for the pending timeout operation. Must remain valid while the |
| // operation is outstanding. |
| __kernel_timespec timeout_; |
| |
| // Mutex to protect access to the registered I/O objects. |
| mutex registration_mutex_; |
| |
| // Keep track of all registered I/O objects. |
| object_pool<io_object> registered_io_objects_; |
| |
| // Helper class to do post-perform_io cleanup. |
| struct perform_io_cleanup_on_block_exit; |
| friend struct perform_io_cleanup_on_block_exit; |
| |
| // The reactor used to register for eventfd readiness. |
| reactor& reactor_; |
| |
| // The per-descriptor reactor data used for the eventfd. |
| reactor::per_descriptor_data reactor_data_; |
| |
| // The eventfd descriptor used to wait for readiness. |
| int event_fd_; |
| }; |
| |
| } // namespace detail |
| } // namespace asio |
| |
| #include "asio/detail/pop_options.hpp" |
| |
| #include "asio/detail/impl/io_uring_service.hpp" |
| #if defined(ASIO_HEADER_ONLY) |
| # include "asio/detail/impl/io_uring_service.ipp" |
| #endif // defined(ASIO_HEADER_ONLY) |
| |
| #endif // defined(ASIO_HAS_IO_URING) |
| |
| #endif // ASIO_DETAIL_IO_URING_SERVICE_HPP |