From e95946831f8ef53d29590735a2df661385edb008 Mon Sep 17 00:00:00 2001 From: "Matthias P. Braendli" Date: Mon, 6 Aug 2018 10:35:22 +0200 Subject: Replace boost by the standalone asio library --- lib/asio/spawn.hpp | 336 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 336 insertions(+) create mode 100644 lib/asio/spawn.hpp (limited to 'lib/asio/spawn.hpp') diff --git a/lib/asio/spawn.hpp b/lib/asio/spawn.hpp new file mode 100644 index 0000000..a91c581 --- /dev/null +++ b/lib/asio/spawn.hpp @@ -0,0 +1,336 @@ +// +// spawn.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_SPAWN_HPP +#define ASIO_SPAWN_HPP + +#if defined(_MSC_VER) && (_MSC_VER >= 1200) +# pragma once +#endif // defined(_MSC_VER) && (_MSC_VER >= 1200) + +#include "asio/detail/config.hpp" +#include +#include "asio/bind_executor.hpp" +#include "asio/detail/memory.hpp" +#include "asio/detail/type_traits.hpp" +#include "asio/detail/wrapped_handler.hpp" +#include "asio/executor.hpp" +#include "asio/io_context.hpp" +#include "asio/is_executor.hpp" +#include "asio/strand.hpp" + +#include "asio/detail/push_options.hpp" + +namespace asio { + +/// Context object the represents the currently executing coroutine. +/** + * The basic_yield_context class is used to represent the currently executing + * stackful coroutine. A basic_yield_context may be passed as a handler to an + * asynchronous operation. For example: + * + * @code template + * void my_coroutine(basic_yield_context yield) + * { + * ... + * std::size_t n = my_socket.async_read_some(buffer, yield); + * ... + * } @endcode + * + * The initiating function (async_read_some in the above example) suspends the + * current coroutine. The coroutine is resumed when the asynchronous operation + * completes, and the result of the operation is returned. + */ +template +class basic_yield_context +{ +public: + /// The coroutine callee type, used by the implementation. + /** + * When using Boost.Coroutine v1, this type is: + * @code typename coroutine @endcode + * When using Boost.Coroutine v2 (unidirectional coroutines), this type is: + * @code push_coroutine @endcode + */ +#if defined(GENERATING_DOCUMENTATION) + typedef implementation_defined callee_type; +#elif defined(BOOST_COROUTINES_UNIDIRECT) || defined(BOOST_COROUTINES_V2) + typedef boost::coroutines::push_coroutine callee_type; +#else + typedef boost::coroutines::coroutine callee_type; +#endif + + /// The coroutine caller type, used by the implementation. + /** + * When using Boost.Coroutine v1, this type is: + * @code typename coroutine::caller_type @endcode + * When using Boost.Coroutine v2 (unidirectional coroutines), this type is: + * @code pull_coroutine @endcode + */ +#if defined(GENERATING_DOCUMENTATION) + typedef implementation_defined caller_type; +#elif defined(BOOST_COROUTINES_UNIDIRECT) || defined(BOOST_COROUTINES_V2) + typedef boost::coroutines::pull_coroutine caller_type; +#else + typedef boost::coroutines::coroutine::caller_type caller_type; +#endif + + /// Construct a yield context to represent the specified coroutine. + /** + * Most applications do not need to use this constructor. Instead, the + * spawn() function passes a yield context as an argument to the coroutine + * function. + */ + basic_yield_context( + const detail::weak_ptr& coro, + caller_type& ca, Handler& handler) + : coro_(coro), + ca_(ca), + handler_(handler), + ec_(0) + { + } + + /// Construct a yield context from another yield context type. + /** + * Requires that OtherHandler be convertible to Handler. + */ + template + basic_yield_context(const basic_yield_context& other) + : coro_(other.coro_), + ca_(other.ca_), + handler_(other.handler_), + ec_(other.ec_) + { + } + + /// Return a yield context that sets the specified error_code. + /** + * By default, when a yield context is used with an asynchronous operation, a + * non-success error_code is converted to system_error and thrown. This + * operator may be used to specify an error_code object that should instead be + * set with the asynchronous operation's result. For example: + * + * @code template + * void my_coroutine(basic_yield_context yield) + * { + * ... + * std::size_t n = my_socket.async_read_some(buffer, yield[ec]); + * if (ec) + * { + * // An error occurred. + * } + * ... + * } @endcode + */ + basic_yield_context operator[](asio::error_code& ec) const + { + basic_yield_context tmp(*this); + tmp.ec_ = &ec; + return tmp; + } + +#if defined(GENERATING_DOCUMENTATION) +private: +#endif // defined(GENERATING_DOCUMENTATION) + detail::weak_ptr coro_; + caller_type& ca_; + Handler handler_; + asio::error_code* ec_; +}; + +#if defined(GENERATING_DOCUMENTATION) +/// Context object that represents the currently executing coroutine. +typedef basic_yield_context yield_context; +#else // defined(GENERATING_DOCUMENTATION) +typedef basic_yield_context< + executor_binder > yield_context; +#endif // defined(GENERATING_DOCUMENTATION) + +/** + * @defgroup spawn asio::spawn + * + * @brief Start a new stackful coroutine. + * + * The spawn() function is a high-level wrapper over the Boost.Coroutine + * library. This function enables programs to implement asynchronous logic in a + * synchronous manner, as illustrated by the following example: + * + * @code asio::spawn(my_strand, do_echo); + * + * // ... + * + * void do_echo(asio::yield_context yield) + * { + * try + * { + * char data[128]; + * for (;;) + * { + * std::size_t length = + * my_socket.async_read_some( + * asio::buffer(data), yield); + * + * asio::async_write(my_socket, + * asio::buffer(data, length), yield); + * } + * } + * catch (std::exception& e) + * { + * // ... + * } + * } @endcode + */ +/*@{*/ + +/// Start a new stackful coroutine, calling the specified handler when it +/// completes. +/** + * This function is used to launch a new coroutine. + * + * @param function The coroutine function. The function must have the signature: + * @code void function(basic_yield_context yield); @endcode + * + * @param attributes Boost.Coroutine attributes used to customise the coroutine. + */ +template +void spawn(ASIO_MOVE_ARG(Function) function, + const boost::coroutines::attributes& attributes + = boost::coroutines::attributes()); + +/// Start a new stackful coroutine, calling the specified handler when it +/// completes. +/** + * This function is used to launch a new coroutine. + * + * @param handler A handler to be called when the coroutine exits. More + * importantly, the handler provides an execution context (via the the handler + * invocation hook) for the coroutine. The handler must have the signature: + * @code void handler(); @endcode + * + * @param function The coroutine function. The function must have the signature: + * @code void function(basic_yield_context yield); @endcode + * + * @param attributes Boost.Coroutine attributes used to customise the coroutine. + */ +template +void spawn(ASIO_MOVE_ARG(Handler) handler, + ASIO_MOVE_ARG(Function) function, + const boost::coroutines::attributes& attributes + = boost::coroutines::attributes(), + typename enable_if::type>::value && + !is_convertible::value>::type* = 0); + +/// Start a new stackful coroutine, inheriting the execution context of another. +/** + * This function is used to launch a new coroutine. + * + * @param ctx Identifies the current coroutine as a parent of the new + * coroutine. This specifies that the new coroutine should inherit the + * execution context of the parent. For example, if the parent coroutine is + * executing in a particular strand, then the new coroutine will execute in the + * same strand. + * + * @param function The coroutine function. The function must have the signature: + * @code void function(basic_yield_context yield); @endcode + * + * @param attributes Boost.Coroutine attributes used to customise the coroutine. + */ +template +void spawn(basic_yield_context ctx, + ASIO_MOVE_ARG(Function) function, + const boost::coroutines::attributes& attributes + = boost::coroutines::attributes()); + +/// Start a new stackful coroutine that executes on a given executor. +/** + * This function is used to launch a new coroutine. + * + * @param ex Identifies the executor that will run the coroutine. The new + * coroutine is implicitly given its own strand within this executor. + * + * @param function The coroutine function. The function must have the signature: + * @code void function(yield_context yield); @endcode + * + * @param attributes Boost.Coroutine attributes used to customise the coroutine. + */ +template +void spawn(const Executor& ex, + ASIO_MOVE_ARG(Function) function, + const boost::coroutines::attributes& attributes + = boost::coroutines::attributes(), + typename enable_if::value>::type* = 0); + +/// Start a new stackful coroutine that executes on a given strand. +/** + * This function is used to launch a new coroutine. + * + * @param ex Identifies the strand that will run the coroutine. + * + * @param function The coroutine function. The function must have the signature: + * @code void function(yield_context yield); @endcode + * + * @param attributes Boost.Coroutine attributes used to customise the coroutine. + */ +template +void spawn(const strand& ex, + ASIO_MOVE_ARG(Function) function, + const boost::coroutines::attributes& attributes + = boost::coroutines::attributes()); + +/// Start a new stackful coroutine that executes in the context of a strand. +/** + * This function is used to launch a new coroutine. + * + * @param s Identifies a strand. By starting multiple coroutines on the same + * strand, the implementation ensures that none of those coroutines can execute + * simultaneously. + * + * @param function The coroutine function. The function must have the signature: + * @code void function(yield_context yield); @endcode + * + * @param attributes Boost.Coroutine attributes used to customise the coroutine. + */ +template +void spawn(const asio::io_context::strand& s, + ASIO_MOVE_ARG(Function) function, + const boost::coroutines::attributes& attributes + = boost::coroutines::attributes()); + +/// Start a new stackful coroutine that executes on a given execution context. +/** + * This function is used to launch a new coroutine. + * + * @param ctx Identifies the execution context that will run the coroutine. The + * new coroutine is implicitly given its own strand within this execution + * context. + * + * @param function The coroutine function. The function must have the signature: + * @code void function(yield_context yield); @endcode + * + * @param attributes Boost.Coroutine attributes used to customise the coroutine. + */ +template +void spawn(ExecutionContext& ctx, + ASIO_MOVE_ARG(Function) function, + const boost::coroutines::attributes& attributes + = boost::coroutines::attributes(), + typename enable_if::value>::type* = 0); + +/*@}*/ + +} // namespace asio + +#include "asio/detail/pop_options.hpp" + +#include "asio/impl/spawn.hpp" + +#endif // ASIO_SPAWN_HPP -- cgit v1.2.3