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Diffstat (limited to 'lib/asio/executor.hpp')
-rw-r--r-- | lib/asio/executor.hpp | 341 |
1 files changed, 341 insertions, 0 deletions
diff --git a/lib/asio/executor.hpp b/lib/asio/executor.hpp new file mode 100644 index 0000000..e552cfb --- /dev/null +++ b/lib/asio/executor.hpp @@ -0,0 +1,341 @@ +// +// executor.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_EXECUTOR_HPP +#define ASIO_EXECUTOR_HPP + +#if defined(_MSC_VER) && (_MSC_VER >= 1200) +# pragma once +#endif // defined(_MSC_VER) && (_MSC_VER >= 1200) + +#include "asio/detail/config.hpp" +#include <typeinfo> +#include "asio/detail/cstddef.hpp" +#include "asio/detail/memory.hpp" +#include "asio/detail/throw_exception.hpp" +#include "asio/execution_context.hpp" + +#include "asio/detail/push_options.hpp" + +namespace asio { + +/// Exception thrown when trying to access an empty polymorphic executor. +class bad_executor + : public std::exception +{ +public: + /// Constructor. + ASIO_DECL bad_executor() ASIO_NOEXCEPT; + + /// Obtain message associated with exception. + ASIO_DECL virtual const char* what() const + ASIO_NOEXCEPT_OR_NOTHROW; +}; + +/// Polymorphic wrapper for executors. +class executor +{ +public: + /// Default constructor. + executor() ASIO_NOEXCEPT + : impl_(0) + { + } + + /// Construct from nullptr. + executor(nullptr_t) ASIO_NOEXCEPT + : impl_(0) + { + } + + /// Copy constructor. + executor(const executor& other) ASIO_NOEXCEPT + : impl_(other.clone()) + { + } + +#if defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION) + /// Move constructor. + executor(executor&& other) ASIO_NOEXCEPT + : impl_(other.impl_) + { + other.impl_ = 0; + } +#endif // defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION) + + /// Construct a polymorphic wrapper for the specified executor. + template <typename Executor> + executor(Executor e); + + /// Allocator-aware constructor to create a polymorphic wrapper for the + /// specified executor. + template <typename Executor, typename Allocator> + executor(allocator_arg_t, const Allocator& a, Executor e); + + /// Destructor. + ~executor() + { + destroy(); + } + + /// Assignment operator. + executor& operator=(const executor& other) ASIO_NOEXCEPT + { + destroy(); + impl_ = other.clone(); + return *this; + } + +#if defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION) + // Move assignment operator. + executor& operator=(executor&& other) ASIO_NOEXCEPT + { + destroy(); + impl_ = other.impl_; + other.impl_ = 0; + return *this; + } +#endif // defined(ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION) + + /// Assignment operator for nullptr_t. + executor& operator=(nullptr_t) ASIO_NOEXCEPT + { + destroy(); + impl_ = 0; + return *this; + } + + /// Assignment operator to create a polymorphic wrapper for the specified + /// executor. + template <typename Executor> + executor& operator=(ASIO_MOVE_ARG(Executor) e) ASIO_NOEXCEPT + { + executor tmp(ASIO_MOVE_CAST(Executor)(e)); + destroy(); + impl_ = tmp.impl_; + tmp.impl_ = 0; + return *this; + } + + /// Obtain the underlying execution context. + execution_context& context() const ASIO_NOEXCEPT + { + return get_impl()->context(); + } + + /// Inform the executor that it has some outstanding work to do. + void on_work_started() const ASIO_NOEXCEPT + { + get_impl()->on_work_started(); + } + + /// Inform the executor that some work is no longer outstanding. + void on_work_finished() const ASIO_NOEXCEPT + { + get_impl()->on_work_finished(); + } + + /// Request the executor to invoke the given function object. + /** + * This function is used to ask the executor to execute the given function + * object. The function object is executed according to the rules of the + * target executor object. + * + * @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 executor to invoke the given function object. + /** + * This function is used to ask the executor to execute the given function + * object. The function object is executed according to the rules of the + * target executor object. + * + * @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 executor to invoke the given function object. + /** + * This function is used to ask the executor to execute the given function + * object. The function object is executed according to the rules of the + * target executor object. + * + * @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; + + struct unspecified_bool_type_t {}; + typedef void (*unspecified_bool_type)(unspecified_bool_type_t); + static void unspecified_bool_true(unspecified_bool_type_t) {} + + /// Operator to test if the executor contains a valid target. + operator unspecified_bool_type() const ASIO_NOEXCEPT + { + return impl_ ? &executor::unspecified_bool_true : 0; + } + + /// Obtain type information for the target executor object. + /** + * @returns If @c *this has a target type of type @c T, <tt>typeid(T)</tt>; + * otherwise, <tt>typeid(void)</tt>. + */ +#if !defined(ASIO_NO_TYPEID) || defined(GENERATING_DOCUMENTATION) + const std::type_info& target_type() const ASIO_NOEXCEPT + { + return impl_ ? impl_->target_type() : typeid(void); + } +#else // !defined(ASIO_NO_TYPEID) || defined(GENERATING_DOCUMENTATION) + const void* target_type() const ASIO_NOEXCEPT + { + return impl_ ? impl_->target_type() : 0; + } +#endif // !defined(ASIO_NO_TYPEID) || defined(GENERATING_DOCUMENTATION) + + /// Obtain a pointer to the target executor object. + /** + * @returns If <tt>target_type() == typeid(T)</tt>, a pointer to the stored + * executor target; otherwise, a null pointer. + */ + template <typename Executor> + Executor* target() ASIO_NOEXCEPT; + + /// Obtain a pointer to the target executor object. + /** + * @returns If <tt>target_type() == typeid(T)</tt>, a pointer to the stored + * executor target; otherwise, a null pointer. + */ + template <typename Executor> + const Executor* target() const ASIO_NOEXCEPT; + + /// Compare two executors for equality. + friend bool operator==(const executor& a, + const executor& b) ASIO_NOEXCEPT + { + if (a.impl_ == b.impl_) + return true; + if (!a.impl_ || !b.impl_) + return false; + return a.impl_->equals(b.impl_); + } + + /// Compare two executors for inequality. + friend bool operator!=(const executor& a, + const executor& b) ASIO_NOEXCEPT + { + return !(a == b); + } + +private: +#if !defined(GENERATING_DOCUMENTATION) + class function; + template <typename, typename> class impl; + +#if !defined(ASIO_NO_TYPEID) + typedef const std::type_info& type_id_result_type; +#else // !defined(ASIO_NO_TYPEID) + typedef const void* type_id_result_type; +#endif // !defined(ASIO_NO_TYPEID) + + template <typename T> + static type_id_result_type type_id() + { +#if !defined(ASIO_NO_TYPEID) + return typeid(T); +#else // !defined(ASIO_NO_TYPEID) + static int unique_id; + return &unique_id; +#endif // !defined(ASIO_NO_TYPEID) + } + + // Base class for all polymorphic executor implementations. + class impl_base + { + public: + virtual impl_base* clone() const ASIO_NOEXCEPT = 0; + virtual void destroy() ASIO_NOEXCEPT = 0; + virtual execution_context& context() ASIO_NOEXCEPT = 0; + virtual void on_work_started() ASIO_NOEXCEPT = 0; + virtual void on_work_finished() ASIO_NOEXCEPT = 0; + virtual void dispatch(ASIO_MOVE_ARG(function)) = 0; + virtual void post(ASIO_MOVE_ARG(function)) = 0; + virtual void defer(ASIO_MOVE_ARG(function)) = 0; + virtual type_id_result_type target_type() const ASIO_NOEXCEPT = 0; + virtual void* target() ASIO_NOEXCEPT = 0; + virtual const void* target() const ASIO_NOEXCEPT = 0; + virtual bool equals(const impl_base* e) const ASIO_NOEXCEPT = 0; + + protected: + impl_base(bool fast_dispatch) : fast_dispatch_(fast_dispatch) {} + virtual ~impl_base() {} + + private: + friend class executor; + const bool fast_dispatch_; + }; + + // Helper function to check and return the implementation pointer. + impl_base* get_impl() const + { + if (!impl_) + { + bad_executor ex; + asio::detail::throw_exception(ex); + } + return impl_; + } + + // Helper function to clone another implementation. + impl_base* clone() const ASIO_NOEXCEPT + { + return impl_ ? impl_->clone() : 0; + } + + // Helper function to destroy an implementation. + void destroy() ASIO_NOEXCEPT + { + if (impl_) + impl_->destroy(); + } + + impl_base* impl_; +#endif // !defined(GENERATING_DOCUMENTATION) +}; + +} // namespace asio + +ASIO_USES_ALLOCATOR(asio::executor) + +#include "asio/detail/pop_options.hpp" + +#include "asio/impl/executor.hpp" +#if defined(ASIO_HEADER_ONLY) +# include "asio/impl/executor.ipp" +#endif // defined(ASIO_HEADER_ONLY) + +#endif // ASIO_EXECUTOR_HPP |