| // |
| // io_context.hpp |
| // ~~~~~~~~~~~~~~ |
| // |
| // Copyright (c) 2003-2015 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_IO_CONTEXT_HPP |
| #define ASIO_IO_CONTEXT_HPP |
| |
| #if defined(_MSC_VER) && (_MSC_VER >= 1200) |
| # pragma once |
| #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) |
| |
| #include "asio/detail/config.hpp" |
| #include <cstddef> |
| #include <stdexcept> |
| #include <typeinfo> |
| #include "asio/async_result.hpp" |
| #include "asio/detail/noncopyable.hpp" |
| #include "asio/detail/wrapped_handler.hpp" |
| #include "asio/error_code.hpp" |
| #include "asio/execution_context.hpp" |
| #include "asio/is_executor.hpp" |
| |
| #if defined(ASIO_WINDOWS) || defined(__CYGWIN__) |
| # include "asio/detail/winsock_init.hpp" |
| #elif defined(__sun) || defined(__QNX__) || defined(__hpux) || defined(_AIX) \ |
| || defined(__osf__) |
| # include "asio/detail/signal_init.hpp" |
| #endif |
| |
| #include "asio/detail/push_options.hpp" |
| |
| namespace asio { |
| |
| namespace detail { |
| #if defined(ASIO_HAS_IOCP) |
| typedef class win_iocp_io_context io_context_impl; |
| class win_iocp_overlapped_ptr; |
| #else |
| typedef class scheduler io_context_impl; |
| #endif |
| } // namespace detail |
| |
| /// Provides core I/O functionality. |
| /** |
| * The io_context class provides the core I/O functionality for users of the |
| * asynchronous I/O objects, including: |
| * |
| * @li asio::ip::tcp::socket |
| * @li asio::ip::tcp::acceptor |
| * @li asio::ip::udp::socket |
| * @li asio::deadline_timer. |
| * |
| * The io_context class also includes facilities intended for developers of |
| * custom asynchronous services. |
| * |
| * @par Thread Safety |
| * @e Distinct @e objects: Safe.@n |
| * @e Shared @e objects: Safe, with the specific exceptions of the restart() and |
| * notify_fork() functions. Calling restart() while there are unfinished run(), |
| * run_one(), poll() or poll_one() calls results in undefined behaviour. The |
| * notify_fork() function should not be called while any io_context function, |
| * or any function on an I/O object that is associated with the io_context, is |
| * being called in another thread. |
| * |
| * @par Concepts: |
| * Dispatcher. |
| * |
| * @par Synchronous and asynchronous operations |
| * |
| * Synchronous operations on I/O objects implicitly run the io_context object |
| * for an individual operation. The io_context functions run(), run_one(), |
| * poll() or poll_one() must be called for the io_context to perform |
| * asynchronous operations on behalf of a C++ program. Notification that an |
| * asynchronous operation has completed is delivered by invocation of the |
| * associated handler. Handlers are invoked only by a thread that is currently |
| * calling any overload of run(), run_one(), poll() or poll_one() for the |
| * io_context. |
| * |
| * @par Effect of exceptions thrown from handlers |
| * |
| * If an exception is thrown from a handler, the exception is allowed to |
| * propagate through the throwing thread's invocation of run(), run_one(), |
| * poll() or poll_one(). No other threads that are calling any of these |
| * functions are affected. It is then the responsibility of the application to |
| * catch the exception. |
| * |
| * After the exception has been caught, the run(), run_one(), poll() or |
| * poll_one() call may be restarted @em without the need for an intervening |
| * call to restart(). This allows the thread to rejoin the io_context object's |
| * thread pool without impacting any other threads in the pool. |
| * |
| * For example: |
| * |
| * @code |
| * asio::io_context io_context; |
| * ... |
| * for (;;) |
| * { |
| * try |
| * { |
| * io_context.run(); |
| * break; // run() exited normally |
| * } |
| * catch (my_exception& e) |
| * { |
| * // Deal with exception as appropriate. |
| * } |
| * } |
| * @endcode |
| * |
| * @par Stopping the io_context from running out of work |
| * |
| * Some applications may need to prevent an io_context object's run() call from |
| * returning when there is no more work to do. For example, the io_context may |
| * be being run in a background thread that is launched prior to the |
| * application's asynchronous operations. The run() call may be kept running by |
| * creating an object of type asio::io_context::work: |
| * |
| * @code asio::io_context io_context; |
| * asio::io_context::work work(io_context); |
| * ... @endcode |
| * |
| * To effect a shutdown, the application will then need to call the io_context |
| * object's stop() member function. This will cause the io_context run() call |
| * to return as soon as possible, abandoning unfinished operations and without |
| * permitting ready handlers to be dispatched. |
| * |
| * Alternatively, if the application requires that all operations and handlers |
| * be allowed to finish normally, the work object may be explicitly destroyed. |
| * |
| * @code asio::io_context io_context; |
| * auto_ptr<asio::io_context::work> work( |
| * new asio::io_context::work(io_context)); |
| * ... |
| * work.reset(); // Allow run() to exit. @endcode |
| */ |
| class io_context |
| : public execution_context |
| { |
| private: |
| typedef detail::io_context_impl impl_type; |
| #if defined(ASIO_HAS_IOCP) |
| friend class detail::win_iocp_overlapped_ptr; |
| #endif |
| |
| public: |
| class executor_type; |
| friend class executor_type; |
| |
| class work; |
| friend class work; |
| |
| class service; |
| |
| class strand; |
| |
| /// Constructor. |
| ASIO_DECL io_context(); |
| |
| /// Constructor. |
| /** |
| * Construct with a hint about the required level of concurrency. |
| * |
| * @param concurrency_hint A suggestion to the implementation on how many |
| * threads it should allow to run simultaneously. |
| */ |
| ASIO_DECL explicit io_context(int concurrency_hint); |
| |
| /// Destructor. |
| /** |
| * On destruction, the io_context performs the following sequence of |
| * operations: |
| * |
| * @li For each service object @c svc in the io_context set, in reverse order |
| * of the beginning of service object lifetime, performs |
| * @c svc->shutdown(). |
| * |
| * @li Uninvoked handler objects that were scheduled for deferred invocation |
| * on the io_context, or any associated strand, are destroyed. |
| * |
| * @li For each service object @c svc in the io_context set, in reverse order |
| * of the beginning of service object lifetime, performs |
| * <tt>delete static_cast<io_context::service*>(svc)</tt>. |
| * |
| * @note The destruction sequence described above permits programs to |
| * simplify their resource management by using @c shared_ptr<>. Where an |
| * object's lifetime is tied to the lifetime of a connection (or some other |
| * sequence of asynchronous operations), a @c shared_ptr to the object would |
| * be bound into the handlers for all asynchronous operations associated with |
| * it. This works as follows: |
| * |
| * @li When a single connection ends, all associated asynchronous operations |
| * complete. The corresponding handler objects are destroyed, and all |
| * @c shared_ptr references to the objects are destroyed. |
| * |
| * @li To shut down the whole program, the io_context function stop() is |
| * called to terminate any run() calls as soon as possible. The io_context |
| * destructor defined above destroys all handlers, causing all @c shared_ptr |
| * references to all connection objects to be destroyed. |
| */ |
| ASIO_DECL ~io_context(); |
| |
| /// Obtains the executor associated with the io_context. |
| executor_type get_executor() ASIO_NOEXCEPT; |
| |
| /// Run the io_context object's event processing loop. |
| /** |
| * The run() function blocks until all work has finished and there are no |
| * more handlers to be dispatched, or until the io_context has been stopped. |
| * |
| * Multiple threads may call the run() function to set up a pool of threads |
| * from which the io_context may execute handlers. All threads that are |
| * waiting in the pool are equivalent and the io_context may choose any one |
| * of them to invoke a handler. |
| * |
| * A normal exit from the run() function implies that the io_context object |
| * is stopped (the stopped() function returns @c true). Subsequent calls to |
| * run(), run_one(), poll() or poll_one() will return immediately unless there |
| * is a prior call to restart(). |
| * |
| * @return The number of handlers that were executed. |
| * |
| * @throws asio::system_error Thrown on failure. |
| * |
| * @note The run() function must not be called from a thread that is currently |
| * calling one of run(), run_one(), poll() or poll_one() on the same |
| * io_context object. |
| * |
| * The poll() function may also be used to dispatch ready handlers, but |
| * without blocking. |
| */ |
| ASIO_DECL std::size_t run(); |
| |
| /// Run the io_context object's event processing loop. |
| /** |
| * The run() function blocks until all work has finished and there are no |
| * more handlers to be dispatched, or until the io_context has been stopped. |
| * |
| * Multiple threads may call the run() function to set up a pool of threads |
| * from which the io_context may execute handlers. All threads that are |
| * waiting in the pool are equivalent and the io_context may choose any one |
| * of them to invoke a handler. |
| * |
| * A normal exit from the run() function implies that the io_context object |
| * is stopped (the stopped() function returns @c true). Subsequent calls to |
| * run(), run_one(), poll() or poll_one() will return immediately unless there |
| * is a prior call to restart(). |
| * |
| * @param ec Set to indicate what error occurred, if any. |
| * |
| * @return The number of handlers that were executed. |
| * |
| * @note The run() function must not be called from a thread that is currently |
| * calling one of run(), run_one(), poll() or poll_one() on the same |
| * io_context object. |
| * |
| * The poll() function may also be used to dispatch ready handlers, but |
| * without blocking. |
| */ |
| ASIO_DECL std::size_t run(asio::error_code& ec); |
| |
| /// Run the io_context object's event processing loop to execute at most one |
| /// handler. |
| /** |
| * The run_one() function blocks until one handler has been dispatched, or |
| * until the io_context has been stopped. |
| * |
| * @return The number of handlers that were executed. A zero return value |
| * implies that the io_context object is stopped (the stopped() function |
| * returns @c true). Subsequent calls to run(), run_one(), poll() or |
| * poll_one() will return immediately unless there is a prior call to |
| * restart(). |
| * |
| * @throws asio::system_error Thrown on failure. |
| */ |
| ASIO_DECL std::size_t run_one(); |
| |
| /// Run the io_context object's event processing loop to execute at most one |
| /// handler. |
| /** |
| * The run_one() function blocks until one handler has been dispatched, or |
| * until the io_context has been stopped. |
| * |
| * @return The number of handlers that were executed. A zero return value |
| * implies that the io_context object is stopped (the stopped() function |
| * returns @c true). Subsequent calls to run(), run_one(), poll() or |
| * poll_one() will return immediately unless there is a prior call to |
| * restart(). |
| * |
| * @return The number of handlers that were executed. |
| */ |
| ASIO_DECL std::size_t run_one(asio::error_code& ec); |
| |
| /// Run the io_context object's event processing loop to execute ready |
| /// handlers. |
| /** |
| * The poll() function runs handlers that are ready to run, without blocking, |
| * until the io_context has been stopped or there are no more ready handlers. |
| * |
| * @return The number of handlers that were executed. |
| * |
| * @throws asio::system_error Thrown on failure. |
| */ |
| ASIO_DECL std::size_t poll(); |
| |
| /// Run the io_context object's event processing loop to execute ready |
| /// handlers. |
| /** |
| * The poll() function runs handlers that are ready to run, without blocking, |
| * until the io_context has been stopped or there are no more ready handlers. |
| * |
| * @param ec Set to indicate what error occurred, if any. |
| * |
| * @return The number of handlers that were executed. |
| */ |
| ASIO_DECL std::size_t poll(asio::error_code& ec); |
| |
| /// Run the io_context object's event processing loop to execute one ready |
| /// handler. |
| /** |
| * The poll_one() function runs at most one handler that is ready to run, |
| * without blocking. |
| * |
| * @return The number of handlers that were executed. |
| * |
| * @throws asio::system_error Thrown on failure. |
| */ |
| ASIO_DECL std::size_t poll_one(); |
| |
| /// Run the io_context object's event processing loop to execute one ready |
| /// handler. |
| /** |
| * The poll_one() function runs at most one handler that is ready to run, |
| * without blocking. |
| * |
| * @param ec Set to indicate what error occurred, if any. |
| * |
| * @return The number of handlers that were executed. |
| */ |
| ASIO_DECL std::size_t poll_one(asio::error_code& ec); |
| |
| /// Stop the io_context object's event processing loop. |
| /** |
| * This function does not block, but instead simply signals the io_context to |
| * stop. All invocations of its run() or run_one() member functions should |
| * return as soon as possible. Subsequent calls to run(), run_one(), poll() |
| * or poll_one() will return immediately until restart() is called. |
| */ |
| ASIO_DECL void stop(); |
| |
| /// Determine whether the io_context object has been stopped. |
| /** |
| * This function is used to determine whether an io_context object has been |
| * stopped, either through an explicit call to stop(), or due to running out |
| * of work. When an io_context object is stopped, calls to run(), run_one(), |
| * poll() or poll_one() will return immediately without invoking any |
| * handlers. |
| * |
| * @return @c true if the io_context object is stopped, otherwise @c false. |
| */ |
| ASIO_DECL bool stopped() const; |
| |
| /// Restart the io_context in preparation for a subsequent run() invocation. |
| /** |
| * This function must be called prior to any second or later set of |
| * invocations of the run(), run_one(), poll() or poll_one() functions when a |
| * previous invocation of these functions returned due to the io_context |
| * being stopped or running out of work. After a call to restart(), the |
| * io_context object's stopped() function will return @c false. |
| * |
| * This function must not be called while there are any unfinished calls to |
| * the run(), run_one(), poll() or poll_one() functions. |
| */ |
| ASIO_DECL void restart(); |
| |
| #if !defined(ASIO_NO_DEPRECATED) |
| /// (Deprecated: Use restart().) Reset the io_context in preparation for a |
| /// subsequent run() invocation. |
| /** |
| * This function must be called prior to any second or later set of |
| * invocations of the run(), run_one(), poll() or poll_one() functions when a |
| * previous invocation of these functions returned due to the io_context |
| * being stopped or running out of work. After a call to restart(), the |
| * io_context object's stopped() function will return @c false. |
| * |
| * This function must not be called while there are any unfinished calls to |
| * the run(), run_one(), poll() or poll_one() functions. |
| */ |
| void reset(); |
| |
| /// (Deprecated: Use asio::dispatch().) Request the io_context to |
| /// invoke the given handler. |
| /** |
| * This function is used to ask the io_context to execute the given handler. |
| * |
| * The io_context guarantees that the handler will only be called in a thread |
| * in which the run(), run_one(), poll() or poll_one() member functions is |
| * currently being invoked. The handler may be executed inside this function |
| * if the guarantee can be met. |
| * |
| * @param handler The handler to be called. The io_context will make |
| * a copy of the handler object as required. The function signature of the |
| * handler must be: @code void handler(); @endcode |
| * |
| * @note This function throws an exception only if: |
| * |
| * @li the handler's @c asio_handler_allocate function; or |
| * |
| * @li the handler's copy constructor |
| * |
| * throws an exception. |
| */ |
| template <typename CompletionHandler> |
| ASIO_INITFN_RESULT_TYPE(CompletionHandler, void ()) |
| dispatch(ASIO_MOVE_ARG(CompletionHandler) handler); |
| |
| /// (Deprecated: Use asio::post().) Request the io_context to invoke |
| /// the given handler and return immediately. |
| /** |
| * This function is used to ask the io_context to execute the given handler, |
| * but without allowing the io_context to call the handler from inside this |
| * function. |
| * |
| * The io_context guarantees that the handler will only be called in a thread |
| * in which the run(), run_one(), poll() or poll_one() member functions is |
| * currently being invoked. |
| * |
| * @param handler The handler to be called. The io_context will make |
| * a copy of the handler object as required. The function signature of the |
| * handler must be: @code void handler(); @endcode |
| * |
| * @note This function throws an exception only if: |
| * |
| * @li the handler's @c asio_handler_allocate function; or |
| * |
| * @li the handler's copy constructor |
| * |
| * throws an exception. |
| */ |
| template <typename CompletionHandler> |
| ASIO_INITFN_RESULT_TYPE(CompletionHandler, void ()) |
| post(ASIO_MOVE_ARG(CompletionHandler) handler); |
| |
| /// (Deprecated: Use asio::bind_executor().) Create a new handler that |
| /// automatically dispatches the wrapped handler on the io_context. |
| /** |
| * This function is used to create a new handler function object that, when |
| * invoked, will automatically pass the wrapped handler to the io_context |
| * object's dispatch function. |
| * |
| * @param handler The handler to be wrapped. The io_context will make a copy |
| * of the handler object as required. The function signature of the handler |
| * must be: @code void handler(A1 a1, ... An an); @endcode |
| * |
| * @return A function object that, when invoked, passes the wrapped handler to |
| * the io_context object's dispatch function. Given a function object with the |
| * signature: |
| * @code R f(A1 a1, ... An an); @endcode |
| * If this function object is passed to the wrap function like so: |
| * @code io_context.wrap(f); @endcode |
| * then the return value is a function object with the signature |
| * @code void g(A1 a1, ... An an); @endcode |
| * that, when invoked, executes code equivalent to: |
| * @code io_context.dispatch(boost::bind(f, a1, ... an)); @endcode |
| */ |
| template <typename Handler> |
| #if defined(GENERATING_DOCUMENTATION) |
| unspecified |
| #else |
| detail::wrapped_handler<io_context&, Handler> |
| #endif |
| wrap(Handler handler); |
| #endif // !defined(ASIO_NO_DEPRECATED) |
| |
| private: |
| // Helper function to add the implementation. |
| ASIO_DECL impl_type& add_impl(impl_type* impl); |
| |
| // Backwards compatible overload for use with services derived from |
| // io_context::service. |
| template <typename Service> |
| friend Service& use_service(io_context& ioc); |
| |
| #if defined(ASIO_WINDOWS) || defined(__CYGWIN__) |
| detail::winsock_init<> init_; |
| #elif defined(__sun) || defined(__QNX__) || defined(__hpux) || defined(_AIX) \ |
| || defined(__osf__) |
| detail::signal_init<> init_; |
| #endif |
| |
| // The implementation. |
| impl_type& impl_; |
| }; |
| |
| /// Executor used to submit functions to an io_context. |
| class io_context::executor_type |
| { |
| public: |
| /// Obtain the underlying execution context. |
| io_context& context() const ASIO_NOEXCEPT; |
| |
| /// Inform the io_context that it has some outstanding work to do. |
| /** |
| * This function is used to inform the io_context that some work has begun. |
| * This ensures that the io_context's run() and run_one() functions do not |
| * exit while the work is underway. |
| */ |
| void on_work_started() const ASIO_NOEXCEPT; |
| |
| /// Inform the io_context that some work is no longer outstanding. |
| /** |
| * This function is used to inform the io_context that some work has |
| * finished. Once the count of unfinished work reaches zero, the io_context |
| * is stopped and the run() and run_one() functions may exit. |
| */ |
| void on_work_finished() const ASIO_NOEXCEPT; |
| |
| /// Request the io_context to invoke the given function object. |
| /** |
| * This function is used to ask the io_context to execute the given function |
| * object. If the current thread is running the io_context, @c dispatch() |
| * executes the function before returning. Otherwise, the function will be |
| * scheduled to run on the io_context. |
| * |
| * @param f The function object to be called. The executor will make a copy |
| * of the handler object as required. The function signature of the function |
| * object must be: @code void function(); @endcode |
| * |
| * @param a An allocator that may be used by the executor to allocate the |
| * internal storage needed for function invocation. |
| */ |
| template <typename Function, typename Allocator> |
| void dispatch(ASIO_MOVE_ARG(Function) f, const Allocator& a) const; |
| |
| /// Request the io_context to invoke the given function object. |
| /** |
| * This function is used to ask the io_context to execute the given function |
| * object. The function object will never be executed inside @c post(). |
| * Instead, it will be scheduled to run on the io_context. |
| * |
| * @param f The function object to be called. The executor will make a copy |
| * of the handler object as required. The function signature of the function |
| * object must be: @code void function(); @endcode |
| * |
| * @param a An allocator that may be used by the executor to allocate the |
| * internal storage needed for function invocation. |
| */ |
| template <typename Function, typename Allocator> |
| void post(ASIO_MOVE_ARG(Function) f, const Allocator& a) const; |
| |
| /// Request the io_context to invoke the given function object. |
| /** |
| * This function is used to ask the io_context to execute the given function |
| * object. The function object will never be executed inside @c defer(). |
| * Instead, it will be scheduled to run on the io_context. |
| * |
| * If the current thread belongs to the io_context, @c defer() will delay |
| * scheduling the function object until the current thread returns control to |
| * the pool. |
| * |
| * @param f The function object to be called. The executor will make a copy |
| * of the handler object as required. The function signature of the function |
| * object must be: @code void function(); @endcode |
| * |
| * @param a An allocator that may be used by the executor to allocate the |
| * internal storage needed for function invocation. |
| */ |
| template <typename Function, typename Allocator> |
| void defer(ASIO_MOVE_ARG(Function) f, const Allocator& a) const; |
| |
| /// Determine whether the io_context is running in the current thread. |
| /** |
| * @return @c true if the current thread is running the io_context. Otherwise |
| * returns @c false. |
| */ |
| bool running_in_this_thread() const ASIO_NOEXCEPT; |
| |
| /// Compare two executors for equality. |
| /** |
| * Two executors are equal if they refer to the same underlying io_context. |
| */ |
| friend bool operator==(const executor_type& a, |
| const executor_type& b) ASIO_NOEXCEPT |
| { |
| return &a.io_context_ == &b.io_context_; |
| } |
| |
| /// Compare two executors for inequality. |
| /** |
| * Two executors are equal if they refer to the same underlying io_context. |
| */ |
| friend bool operator!=(const executor_type& a, |
| const executor_type& b) ASIO_NOEXCEPT |
| { |
| return &a.io_context_ != &b.io_context_; |
| } |
| |
| private: |
| friend class io_context; |
| |
| // Constructor. |
| explicit executor_type(io_context& i) : io_context_(i) {} |
| |
| // The underlying io_context. |
| io_context& io_context_; |
| }; |
| |
| #if !defined(GENERATING_DOCUMENTATION) |
| template <> struct is_executor<io_context::executor_type> : true_type {}; |
| #endif // !defined(GENERATING_DOCUMENTATION) |
| |
| |
| /// (Deprecated: Use executor_work_guard.) Class to inform the io_context when |
| /// it has work to do. |
| /** |
| * The work class is used to inform the io_context when work starts and |
| * finishes. This ensures that the io_context object's run() function will not |
| * exit while work is underway, and that it does exit when there is no |
| * unfinished work remaining. |
| * |
| * The work class is copy-constructible so that it may be used as a data member |
| * in a handler class. It is not assignable. |
| */ |
| class io_context::work |
| { |
| public: |
| /// Constructor notifies the io_context that work is starting. |
| /** |
| * The constructor is used to inform the io_context that some work has begun. |
| * This ensures that the io_context object's run() function will not exit |
| * while the work is underway. |
| */ |
| explicit work(asio::io_context& io_context); |
| |
| /// Copy constructor notifies the io_context that work is starting. |
| /** |
| * The constructor is used to inform the io_context that some work has begun. |
| * This ensures that the io_context object's run() function will not exit |
| * while the work is underway. |
| */ |
| work(const work& other); |
| |
| /// Destructor notifies the io_context that the work is complete. |
| /** |
| * The destructor is used to inform the io_context that some work has |
| * finished. Once the count of unfinished work reaches zero, the io_context |
| * object's run() function is permitted to exit. |
| */ |
| ~work(); |
| |
| /// Get the io_context associated with the work. |
| asio::io_context& get_io_context(); |
| |
| #if !defined(ASIO_NO_DEPRECATED) |
| /// (Deprecated: Use get_io_context().) Get the io_context associated with the |
| /// work. |
| asio::io_context& get_io_service(); |
| #endif // !defined(ASIO_NO_DEPRECATED) |
| |
| private: |
| // Prevent assignment. |
| void operator=(const work& other); |
| |
| // The io_context implementation. |
| detail::io_context_impl& io_context_impl_; |
| }; |
| |
| /// Base class for all io_context services. |
| class io_context::service |
| : public execution_context::service |
| { |
| public: |
| /// Get the io_context object that owns the service. |
| asio::io_context& get_io_context(); |
| |
| #if !defined(ASIO_NO_DEPRECATED) |
| /// Get the io_context object that owns the service. |
| asio::io_context& get_io_service(); |
| #endif // !defined(ASIO_NO_DEPRECATED) |
| |
| private: |
| /// Destroy all user-defined handler objects owned by the service. |
| ASIO_DECL virtual void shutdown(); |
| |
| #if !defined(ASIO_NO_DEPRECATED) |
| /// (Deprecated: Use shutdown().) Destroy all user-defined handler objects |
| /// owned by the service. |
| ASIO_DECL virtual void shutdown_service(); |
| #endif // !defined(ASIO_NO_DEPRECATED) |
| |
| /// Handle notification of a fork-related event to perform any necessary |
| /// housekeeping. |
| /** |
| * This function is not a pure virtual so that services only have to |
| * implement it if necessary. The default implementation does nothing. |
| */ |
| ASIO_DECL virtual void notify_fork( |
| execution_context::fork_event event); |
| |
| #if !defined(ASIO_NO_DEPRECATED) |
| /// (Deprecated: Use notify_fork().) Handle notification of a fork-related |
| /// event to perform any necessary housekeeping. |
| /** |
| * This function is not a pure virtual so that services only have to |
| * implement it if necessary. The default implementation does nothing. |
| */ |
| ASIO_DECL virtual void fork_service( |
| execution_context::fork_event event); |
| #endif // !defined(ASIO_NO_DEPRECATED) |
| |
| protected: |
| /// Constructor. |
| /** |
| * @param owner The io_context object that owns the service. |
| */ |
| ASIO_DECL service(asio::io_context& owner); |
| |
| /// Destructor. |
| ASIO_DECL virtual ~service(); |
| }; |
| |
| namespace detail { |
| |
| // Special service base class to keep classes header-file only. |
| template <typename Type> |
| class service_base |
| : public asio::io_context::service |
| { |
| public: |
| static asio::detail::service_id<Type> id; |
| |
| // Constructor. |
| service_base(asio::io_context& io_context) |
| : asio::io_context::service(io_context) |
| { |
| } |
| }; |
| |
| template <typename Type> |
| asio::detail::service_id<Type> service_base<Type>::id; |
| |
| } // namespace detail |
| } // namespace asio |
| |
| #include "asio/detail/pop_options.hpp" |
| |
| #include "asio/impl/io_context.hpp" |
| #if defined(ASIO_HEADER_ONLY) |
| # include "asio/impl/io_context.ipp" |
| #endif // defined(ASIO_HEADER_ONLY) |
| |
| // If both io_context.hpp and strand.hpp have been included, automatically |
| // include the header file needed for the io_context::strand class. |
| #if defined(ASIO_STRAND_HPP) |
| # include "asio/io_context_strand.hpp" |
| #endif // defined(ASIO_STRAND_HPP) |
| |
| #endif // ASIO_IO_CONTEXT_HPP |