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Diffstat (limited to 'lib/asio/io_context.hpp')
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diff --git a/lib/asio/io_context.hpp b/lib/asio/io_context.hpp deleted file mode 100644 index 4d93be4..0000000 --- a/lib/asio/io_context.hpp +++ /dev/null @@ -1,876 +0,0 @@ -// -// io_context.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_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" - -#if defined(ASIO_HAS_CHRONO) -# include "asio/detail/chrono.hpp" -#endif // defined(ASIO_HAS_CHRONO) - -#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(), run_for(), run_until(), 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(), - * run_for(), run_until(), 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(), run_for(), - * run_until(), 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(), - * run_for(), run_until(), 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(), run_for(), - * run_until(), 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 Submitting arbitrary tasks to the io_context - * - * To submit functions to the io_context, use the @ref asio::dispatch, - * @ref asio::post or @ref asio::defer free functions. - * - * For example: - * - * @code void my_task() - * { - * ... - * } - * - * ... - * - * asio::io_context io_context; - * - * // Submit a function to the io_context. - * asio::post(io_context, my_task); - * - * // Submit a lambda object to the io_context. - * asio::post(io_context, - * []() - * { - * ... - * }); - * - * // Run the io_context until it runs out of work. - * io_context.run(); @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::executor_work_guard<io_context::executor_type>: - * - * @code asio::io_context io_context; - * asio::executor_work_guard<asio::io_context::executor_type> - * = asio::make_work_guard(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 reset. - * - * @code asio::io_context io_context; - * asio::executor_work_guard<asio::io_context::executor_type> - * = asio::make_work_guard(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; - -#if !defined(ASIO_NO_DEPRECATED) - class work; - friend class work; -#endif // !defined(ASIO_NO_DEPRECATED) - - class service; - -#if !defined(ASIO_NO_EXTENSIONS) - class strand; -#endif // !defined(ASIO_NO_EXTENSIONS) - - /// The type used to count the number of handlers executed by the context. - typedef std::size_t count_type; - - /// 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. - * - * @note Calling the run() function from a thread that is currently calling - * one of run(), run_one(), run_for(), run_until(), poll() or poll_one() on - * the same io_context object may introduce the potential for deadlock. It is - * the caller's reponsibility to avoid this. - * - * The poll() function may also be used to dispatch ready handlers, but - * without blocking. - */ - ASIO_DECL count_type run(); - -#if !defined(ASIO_NO_DEPRECATED) - /// (Deprecated: Use non-error_code overload.) 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 Calling the run() function from a thread that is currently calling - * one of run(), run_one(), run_for(), run_until(), poll() or poll_one() on - * the same io_context object may introduce the potential for deadlock. It is - * the caller's reponsibility to avoid this. - * - * The poll() function may also be used to dispatch ready handlers, but - * without blocking. - */ - ASIO_DECL count_type run(asio::error_code& ec); -#endif // !defined(ASIO_NO_DEPRECATED) - -#if defined(ASIO_HAS_CHRONO) || defined(GENERATING_DOCUMENTATION) - /// Run the io_context object's event processing loop for a specified - /// duration. - /** - * The run_for() function blocks until all work has finished and there are no - * more handlers to be dispatched, until the io_context has been stopped, or - * until the specified duration has elapsed. - * - * @param rel_time The duration for which the call may block. - * - * @return The number of handlers that were executed. - */ - template <typename Rep, typename Period> - std::size_t run_for(const chrono::duration<Rep, Period>& rel_time); - - /// Run the io_context object's event processing loop until a specified time. - /** - * The run_until() function blocks until all work has finished and there are - * no more handlers to be dispatched, until the io_context has been stopped, - * or until the specified time has been reached. - * - * @param abs_time The time point until which the call may block. - * - * @return The number of handlers that were executed. - */ - template <typename Clock, typename Duration> - std::size_t run_until(const chrono::time_point<Clock, Duration>& abs_time); -#endif // defined(ASIO_HAS_CHRONO) || defined(GENERATING_DOCUMENTATION) - - /// 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(). - * - * @note Calling the run_one() function from a thread that is currently - * calling one of run(), run_one(), run_for(), run_until(), poll() or - * poll_one() on the same io_context object may introduce the potential for - * deadlock. It is the caller's reponsibility to avoid this. - */ - ASIO_DECL count_type run_one(); - -#if !defined(ASIO_NO_DEPRECATED) - /// (Deprecated: Use non-error_code overlaod.) 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. - * - * @note Calling the run_one() function from a thread that is currently - * calling one of run(), run_one(), run_for(), run_until(), poll() or - * poll_one() on the same io_context object may introduce the potential for - * deadlock. It is the caller's reponsibility to avoid this. - */ - ASIO_DECL count_type run_one(asio::error_code& ec); -#endif // !defined(ASIO_NO_DEPRECATED) - -#if defined(ASIO_HAS_CHRONO) || defined(GENERATING_DOCUMENTATION) - /// Run the io_context object's event processing loop for a specified duration - /// to execute at most one handler. - /** - * The run_one_for() function blocks until one handler has been dispatched, - * until the io_context has been stopped, or until the specified duration has - * elapsed. - * - * @param rel_time The duration for which the call may block. - * - * @return The number of handlers that were executed. - */ - template <typename Rep, typename Period> - std::size_t run_one_for(const chrono::duration<Rep, Period>& rel_time); - - /// Run the io_context object's event processing loop until a specified time - /// to execute at most one handler. - /** - * The run_one_until() function blocks until one handler has been dispatched, - * until the io_context has been stopped, or until the specified time has - * been reached. - * - * @param abs_time The time point until which the call may block. - * - * @return The number of handlers that were executed. - */ - template <typename Clock, typename Duration> - std::size_t run_one_until( - const chrono::time_point<Clock, Duration>& abs_time); -#endif // defined(ASIO_HAS_CHRONO) || defined(GENERATING_DOCUMENTATION) - - /// 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. - */ - ASIO_DECL count_type poll(); - -#if !defined(ASIO_NO_DEPRECATED) - /// (Deprecated: Use non-error_code overload.) 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 count_type poll(asio::error_code& ec); -#endif // !defined(ASIO_NO_DEPRECATED) - - /// 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. - */ - ASIO_DECL count_type poll_one(); - -#if !defined(ASIO_NO_DEPRECATED) - /// (Deprecated: Use non-error_code overload.) 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 count_type poll_one(asio::error_code& ec); -#endif // !defined(ASIO_NO_DEPRECATED) - - /// 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 LegacyCompletionHandler> - ASIO_INITFN_RESULT_TYPE(LegacyCompletionHandler, void ()) - dispatch(ASIO_MOVE_ARG(LegacyCompletionHandler) 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 LegacyCompletionHandler> - ASIO_INITFN_RESULT_TYPE(LegacyCompletionHandler, void ()) - post(ASIO_MOVE_ARG(LegacyCompletionHandler) 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(ASIO_NO_DEPRECATED) -/// (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(); - - /// (Deprecated: Use get_io_context().) Get the io_context associated with the - /// work. - asio::io_context& get_io_service(); - -private: - // Prevent assignment. - void operator=(const work& other); - - // The io_context implementation. - detail::io_context_impl& io_context_impl_; -}; -#endif // !defined(ASIO_NO_DEPRECATED) - -/// 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_NO_EXTENSIONS) -# if defined(ASIO_STRAND_HPP) -# include "asio/io_context_strand.hpp" -# endif // defined(ASIO_STRAND_HPP) -#endif // !defined(ASIO_NO_EXTENSIONS) - -#endif // ASIO_IO_CONTEXT_HPP |