448 lines
15 KiB
C++
448 lines
15 KiB
C++
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//
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// signal_set.hpp
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// ~~~~~~~~~~~~~~
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//
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// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
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//
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// Distributed under the Boost Software License, Version 1.0. (See accompanying
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// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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//
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#ifndef ASIO_SIGNAL_SET_HPP
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#define ASIO_SIGNAL_SET_HPP
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#if defined(_MSC_VER) && (_MSC_VER >= 1200)
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# pragma once
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#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
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#include "asio/detail/config.hpp"
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#include "asio/async_result.hpp"
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#include "asio/basic_io_object.hpp"
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#include "asio/detail/handler_type_requirements.hpp"
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#include "asio/detail/throw_error.hpp"
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#include "asio/error.hpp"
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#include "asio/io_context.hpp"
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#if defined(ASIO_ENABLE_OLD_SERVICES)
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# include "asio/basic_signal_set.hpp"
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#else // defined(ASIO_ENABLE_OLD_SERVICES)
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# include "asio/detail/signal_set_service.hpp"
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#endif // defined(ASIO_ENABLE_OLD_SERVICES)
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namespace asio {
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#if defined(ASIO_ENABLE_OLD_SERVICES)
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// Typedef for the typical usage of a signal set.
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typedef basic_signal_set<> signal_set;
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#else // defined(ASIO_ENABLE_OLD_SERVICES)
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/// Provides signal functionality.
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/**
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* The signal_set class provides the ability to perform an asynchronous wait
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* for one or more signals to occur.
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*
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* @par Thread Safety
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* @e Distinct @e objects: Safe.@n
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* @e Shared @e objects: Unsafe.
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*
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* @par Example
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* Performing an asynchronous wait:
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* @code
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* void handler(
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* const asio::error_code& error,
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* int signal_number)
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* {
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* if (!error)
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* {
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* // A signal occurred.
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* }
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* }
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*
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* ...
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*
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* // Construct a signal set registered for process termination.
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* asio::signal_set signals(io_context, SIGINT, SIGTERM);
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*
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* // Start an asynchronous wait for one of the signals to occur.
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* signals.async_wait(handler);
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* @endcode
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*
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* @par Queueing of signal notifications
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*
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* If a signal is registered with a signal_set, and the signal occurs when
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* there are no waiting handlers, then the signal notification is queued. The
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* next async_wait operation on that signal_set will dequeue the notification.
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* If multiple notifications are queued, subsequent async_wait operations
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* dequeue them one at a time. Signal notifications are dequeued in order of
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* ascending signal number.
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*
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* If a signal number is removed from a signal_set (using the @c remove or @c
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* erase member functions) then any queued notifications for that signal are
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* discarded.
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*
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* @par Multiple registration of signals
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*
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* The same signal number may be registered with different signal_set objects.
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* When the signal occurs, one handler is called for each signal_set object.
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*
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* Note that multiple registration only works for signals that are registered
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* using Asio. The application must not also register a signal handler using
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* functions such as @c signal() or @c sigaction().
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*
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* @par Signal masking on POSIX platforms
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*
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* POSIX allows signals to be blocked using functions such as @c sigprocmask()
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* and @c pthread_sigmask(). For signals to be delivered, programs must ensure
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* that any signals registered using signal_set objects are unblocked in at
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* least one thread.
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*/
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class signal_set
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: ASIO_SVC_ACCESS basic_io_object<detail::signal_set_service>
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{
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public:
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/// The type of the executor associated with the object.
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typedef io_context::executor_type executor_type;
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/// Construct a signal set without adding any signals.
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/**
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* This constructor creates a signal set without registering for any signals.
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*
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* @param io_context The io_context object that the signal set will use to
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* dispatch handlers for any asynchronous operations performed on the set.
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*/
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explicit signal_set(asio::io_context& io_context)
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: basic_io_object<detail::signal_set_service>(io_context)
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{
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}
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/// Construct a signal set and add one signal.
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/**
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* This constructor creates a signal set and registers for one signal.
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*
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* @param io_context The io_context object that the signal set will use to
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* dispatch handlers for any asynchronous operations performed on the set.
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*
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* @param signal_number_1 The signal number to be added.
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*
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* @note This constructor is equivalent to performing:
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* @code asio::signal_set signals(io_context);
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* signals.add(signal_number_1); @endcode
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*/
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signal_set(asio::io_context& io_context, int signal_number_1)
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: basic_io_object<detail::signal_set_service>(io_context)
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{
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asio::error_code ec;
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this->get_service().add(this->get_implementation(), signal_number_1, ec);
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asio::detail::throw_error(ec, "add");
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}
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/// Construct a signal set and add two signals.
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/**
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* This constructor creates a signal set and registers for two signals.
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*
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* @param io_context The io_context object that the signal set will use to
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* dispatch handlers for any asynchronous operations performed on the set.
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*
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* @param signal_number_1 The first signal number to be added.
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*
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* @param signal_number_2 The second signal number to be added.
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*
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* @note This constructor is equivalent to performing:
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* @code asio::signal_set signals(io_context);
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* signals.add(signal_number_1);
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* signals.add(signal_number_2); @endcode
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*/
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signal_set(asio::io_context& io_context, int signal_number_1,
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int signal_number_2)
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: basic_io_object<detail::signal_set_service>(io_context)
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{
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asio::error_code ec;
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this->get_service().add(this->get_implementation(), signal_number_1, ec);
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asio::detail::throw_error(ec, "add");
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this->get_service().add(this->get_implementation(), signal_number_2, ec);
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asio::detail::throw_error(ec, "add");
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}
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/// Construct a signal set and add three signals.
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/**
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* This constructor creates a signal set and registers for three signals.
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*
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* @param io_context The io_context object that the signal set will use to
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* dispatch handlers for any asynchronous operations performed on the set.
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*
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* @param signal_number_1 The first signal number to be added.
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*
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* @param signal_number_2 The second signal number to be added.
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*
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* @param signal_number_3 The third signal number to be added.
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*
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* @note This constructor is equivalent to performing:
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* @code asio::signal_set signals(io_context);
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* signals.add(signal_number_1);
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* signals.add(signal_number_2);
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* signals.add(signal_number_3); @endcode
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*/
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signal_set(asio::io_context& io_context, int signal_number_1,
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int signal_number_2, int signal_number_3)
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: basic_io_object<detail::signal_set_service>(io_context)
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{
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asio::error_code ec;
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this->get_service().add(this->get_implementation(), signal_number_1, ec);
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asio::detail::throw_error(ec, "add");
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this->get_service().add(this->get_implementation(), signal_number_2, ec);
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asio::detail::throw_error(ec, "add");
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this->get_service().add(this->get_implementation(), signal_number_3, ec);
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asio::detail::throw_error(ec, "add");
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}
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/// Destroys the signal set.
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/**
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* This function destroys the signal set, cancelling any outstanding
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* asynchronous wait operations associated with the signal set as if by
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* calling @c cancel.
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*/
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~signal_set()
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{
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}
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#if !defined(ASIO_NO_DEPRECATED)
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/// (Deprecated: Use get_executor().) Get the io_context associated with the
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/// object.
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/**
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* This function may be used to obtain the io_context object that the I/O
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* object uses to dispatch handlers for asynchronous operations.
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*
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* @return A reference to the io_context object that the I/O object will use
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* to dispatch handlers. Ownership is not transferred to the caller.
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*/
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asio::io_context& get_io_context()
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{
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return basic_io_object<detail::signal_set_service>::get_io_context();
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}
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/// (Deprecated: Use get_executor().) Get the io_context associated with the
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/// object.
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/**
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* This function may be used to obtain the io_context object that the I/O
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* object uses to dispatch handlers for asynchronous operations.
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*
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* @return A reference to the io_context object that the I/O object will use
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* to dispatch handlers. Ownership is not transferred to the caller.
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*/
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asio::io_context& get_io_service()
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{
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return basic_io_object<detail::signal_set_service>::get_io_service();
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}
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#endif // !defined(ASIO_NO_DEPRECATED)
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/// Get the executor associated with the object.
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executor_type get_executor() ASIO_NOEXCEPT
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{
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return basic_io_object<detail::signal_set_service>::get_executor();
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}
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/// Add a signal to a signal_set.
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/**
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* This function adds the specified signal to the set. It has no effect if the
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* signal is already in the set.
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*
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* @param signal_number The signal to be added to the set.
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*
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* @throws asio::system_error Thrown on failure.
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*/
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void add(int signal_number)
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{
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asio::error_code ec;
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this->get_service().add(this->get_implementation(), signal_number, ec);
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asio::detail::throw_error(ec, "add");
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}
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/// Add a signal to a signal_set.
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/**
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* This function adds the specified signal to the set. It has no effect if the
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* signal is already in the set.
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*
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* @param signal_number The signal to be added to the set.
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*
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* @param ec Set to indicate what error occurred, if any.
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*/
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ASIO_SYNC_OP_VOID add(int signal_number,
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asio::error_code& ec)
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{
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this->get_service().add(this->get_implementation(), signal_number, ec);
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ASIO_SYNC_OP_VOID_RETURN(ec);
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}
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/// Remove a signal from a signal_set.
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/**
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* This function removes the specified signal from the set. It has no effect
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* if the signal is not in the set.
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*
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* @param signal_number The signal to be removed from the set.
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*
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* @throws asio::system_error Thrown on failure.
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*
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* @note Removes any notifications that have been queued for the specified
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* signal number.
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*/
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void remove(int signal_number)
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{
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asio::error_code ec;
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this->get_service().remove(this->get_implementation(), signal_number, ec);
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asio::detail::throw_error(ec, "remove");
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}
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/// Remove a signal from a signal_set.
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/**
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* This function removes the specified signal from the set. It has no effect
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* if the signal is not in the set.
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*
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* @param signal_number The signal to be removed from the set.
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*
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* @param ec Set to indicate what error occurred, if any.
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*
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* @note Removes any notifications that have been queued for the specified
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* signal number.
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*/
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ASIO_SYNC_OP_VOID remove(int signal_number,
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asio::error_code& ec)
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{
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this->get_service().remove(this->get_implementation(), signal_number, ec);
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ASIO_SYNC_OP_VOID_RETURN(ec);
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}
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/// Remove all signals from a signal_set.
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/**
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* This function removes all signals from the set. It has no effect if the set
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* is already empty.
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*
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* @throws asio::system_error Thrown on failure.
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*
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* @note Removes all queued notifications.
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*/
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void clear()
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{
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asio::error_code ec;
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this->get_service().clear(this->get_implementation(), ec);
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asio::detail::throw_error(ec, "clear");
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}
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/// Remove all signals from a signal_set.
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/**
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* This function removes all signals from the set. It has no effect if the set
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* is already empty.
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*
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* @param ec Set to indicate what error occurred, if any.
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*
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* @note Removes all queued notifications.
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*/
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ASIO_SYNC_OP_VOID clear(asio::error_code& ec)
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{
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this->get_service().clear(this->get_implementation(), ec);
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ASIO_SYNC_OP_VOID_RETURN(ec);
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}
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/// Cancel all operations associated with the signal set.
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/**
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* This function forces the completion of any pending asynchronous wait
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* operations against the signal set. The handler for each cancelled
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* operation will be invoked with the asio::error::operation_aborted
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* error code.
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*
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* Cancellation does not alter the set of registered signals.
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*
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* @throws asio::system_error Thrown on failure.
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*
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* @note If a registered signal occurred before cancel() is called, then the
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* handlers for asynchronous wait operations will:
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*
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* @li have already been invoked; or
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*
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* @li have been queued for invocation in the near future.
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*
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* These handlers can no longer be cancelled, and therefore are passed an
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* error code that indicates the successful completion of the wait operation.
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*/
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void cancel()
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{
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asio::error_code ec;
|
||
|
|
this->get_service().cancel(this->get_implementation(), ec);
|
||
|
|
asio::detail::throw_error(ec, "cancel");
|
||
|
|
}
|
||
|
|
|
||
|
|
/// Cancel all operations associated with the signal set.
|
||
|
|
/**
|
||
|
|
* This function forces the completion of any pending asynchronous wait
|
||
|
|
* operations against the signal set. The handler for each cancelled
|
||
|
|
* operation will be invoked with the asio::error::operation_aborted
|
||
|
|
* error code.
|
||
|
|
*
|
||
|
|
* Cancellation does not alter the set of registered signals.
|
||
|
|
*
|
||
|
|
* @param ec Set to indicate what error occurred, if any.
|
||
|
|
*
|
||
|
|
* @note If a registered signal occurred before cancel() is called, then the
|
||
|
|
* handlers for asynchronous wait operations will:
|
||
|
|
*
|
||
|
|
* @li have already been invoked; or
|
||
|
|
*
|
||
|
|
* @li have been queued for invocation in the near future.
|
||
|
|
*
|
||
|
|
* These handlers can no longer be cancelled, and therefore are passed an
|
||
|
|
* error code that indicates the successful completion of the wait operation.
|
||
|
|
*/
|
||
|
|
ASIO_SYNC_OP_VOID cancel(asio::error_code& ec)
|
||
|
|
{
|
||
|
|
this->get_service().cancel(this->get_implementation(), ec);
|
||
|
|
ASIO_SYNC_OP_VOID_RETURN(ec);
|
||
|
|
}
|
||
|
|
|
||
|
|
/// Start an asynchronous operation to wait for a signal to be delivered.
|
||
|
|
/**
|
||
|
|
* This function may be used to initiate an asynchronous wait against the
|
||
|
|
* signal set. It always returns immediately.
|
||
|
|
*
|
||
|
|
* For each call to async_wait(), the supplied handler will be called exactly
|
||
|
|
* once. The handler will be called when:
|
||
|
|
*
|
||
|
|
* @li One of the registered signals in the signal set occurs; or
|
||
|
|
*
|
||
|
|
* @li The signal set was cancelled, in which case the handler is passed the
|
||
|
|
* error code asio::error::operation_aborted.
|
||
|
|
*
|
||
|
|
* @param handler The handler to be called when the signal occurs. Copies
|
||
|
|
* will be made of the handler as required. The function signature of the
|
||
|
|
* handler must be:
|
||
|
|
* @code void handler(
|
||
|
|
* const asio::error_code& error, // Result of operation.
|
||
|
|
* int signal_number // Indicates which signal occurred.
|
||
|
|
* ); @endcode
|
||
|
|
* Regardless of whether the asynchronous operation completes immediately or
|
||
|
|
* not, the handler will not be invoked from within this function. Invocation
|
||
|
|
* of the handler will be performed in a manner equivalent to using
|
||
|
|
* asio::io_context::post().
|
||
|
|
*/
|
||
|
|
template <typename SignalHandler>
|
||
|
|
ASIO_INITFN_RESULT_TYPE(SignalHandler,
|
||
|
|
void (asio::error_code, int))
|
||
|
|
async_wait(ASIO_MOVE_ARG(SignalHandler) handler)
|
||
|
|
{
|
||
|
|
// If you get an error on the following line it means that your handler does
|
||
|
|
// not meet the documented type requirements for a SignalHandler.
|
||
|
|
ASIO_SIGNAL_HANDLER_CHECK(SignalHandler, handler) type_check;
|
||
|
|
|
||
|
|
async_completion<SignalHandler,
|
||
|
|
void (asio::error_code, int)> init(handler);
|
||
|
|
|
||
|
|
this->get_service().async_wait(this->get_implementation(),
|
||
|
|
init.completion_handler);
|
||
|
|
|
||
|
|
return init.result.get();
|
||
|
|
}
|
||
|
|
};
|
||
|
|
#endif // defined(ASIO_ENABLE_OLD_SERVICES)
|
||
|
|
|
||
|
|
} // namespace asio
|
||
|
|
|
||
|
|
#endif // ASIO_SIGNAL_SET_HPP
|