Insane_DNS/libraries/asio-1.28.1/include/asio/detail/signal_set_service.hpp

293 lines
8.4 KiB
C++

//
// detail/signal_set_service.hpp
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2023 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_DETAIL_SIGNAL_SET_SERVICE_HPP
#define ASIO_DETAIL_SIGNAL_SET_SERVICE_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 <signal.h>
#include "asio/associated_cancellation_slot.hpp"
#include "asio/cancellation_type.hpp"
#include "asio/error.hpp"
#include "asio/execution_context.hpp"
#include "asio/signal_set_base.hpp"
#include "asio/detail/handler_alloc_helpers.hpp"
#include "asio/detail/memory.hpp"
#include "asio/detail/op_queue.hpp"
#include "asio/detail/signal_handler.hpp"
#include "asio/detail/signal_op.hpp"
#include "asio/detail/socket_types.hpp"
#if defined(ASIO_HAS_IOCP)
# include "asio/detail/win_iocp_io_context.hpp"
#else // defined(ASIO_HAS_IOCP)
# include "asio/detail/scheduler.hpp"
#endif // defined(ASIO_HAS_IOCP)
#if !defined(ASIO_WINDOWS) && !defined(__CYGWIN__)
# if defined(ASIO_HAS_IO_URING_AS_DEFAULT)
# include "asio/detail/io_uring_service.hpp"
# else // defined(ASIO_HAS_IO_URING_AS_DEFAULT)
# include "asio/detail/reactor.hpp"
# endif // defined(ASIO_HAS_IO_URING_AS_DEFAULT)
#endif // !defined(ASIO_WINDOWS) && !defined(__CYGWIN__)
#include "asio/detail/push_options.hpp"
namespace asio {
namespace detail {
#if defined(NSIG) && (NSIG > 0)
enum { max_signal_number = NSIG };
#else
enum { max_signal_number = 128 };
#endif
extern ASIO_DECL struct signal_state* get_signal_state();
extern "C" ASIO_DECL void asio_signal_handler(int signal_number);
class signal_set_service :
public execution_context_service_base<signal_set_service>
{
public:
// Type used for tracking an individual signal registration.
class registration
{
public:
// Default constructor.
registration()
: signal_number_(0),
queue_(0),
undelivered_(0),
next_in_table_(0),
prev_in_table_(0),
next_in_set_(0)
{
}
private:
// Only this service will have access to the internal values.
friend class signal_set_service;
// The signal number that is registered.
int signal_number_;
// The waiting signal handlers.
op_queue<signal_op>* queue_;
// The number of undelivered signals.
std::size_t undelivered_;
// Pointers to adjacent registrations in the registrations_ table.
registration* next_in_table_;
registration* prev_in_table_;
// Link to next registration in the signal set.
registration* next_in_set_;
};
// The implementation type of the signal_set.
class implementation_type
{
public:
// Default constructor.
implementation_type()
: signals_(0)
{
}
private:
// Only this service will have access to the internal values.
friend class signal_set_service;
// The pending signal handlers.
op_queue<signal_op> queue_;
// Linked list of registered signals.
registration* signals_;
};
// Constructor.
ASIO_DECL signal_set_service(execution_context& context);
// Destructor.
ASIO_DECL ~signal_set_service();
// Destroy all user-defined handler objects owned by the service.
ASIO_DECL void shutdown();
// Perform fork-related housekeeping.
ASIO_DECL void notify_fork(
asio::execution_context::fork_event fork_ev);
// Construct a new signal_set implementation.
ASIO_DECL void construct(implementation_type& impl);
// Destroy a signal_set implementation.
ASIO_DECL void destroy(implementation_type& impl);
// Add a signal to a signal_set.
asio::error_code add(implementation_type& impl,
int signal_number, asio::error_code& ec)
{
return add(impl, signal_number, signal_set_base::flags::dont_care, ec);
}
// Add a signal to a signal_set with the specified flags.
ASIO_DECL asio::error_code add(implementation_type& impl,
int signal_number, signal_set_base::flags_t f,
asio::error_code& ec);
// Remove a signal to a signal_set.
ASIO_DECL asio::error_code remove(implementation_type& impl,
int signal_number, asio::error_code& ec);
// Remove all signals from a signal_set.
ASIO_DECL asio::error_code clear(implementation_type& impl,
asio::error_code& ec);
// Cancel all operations associated with the signal set.
ASIO_DECL asio::error_code cancel(implementation_type& impl,
asio::error_code& ec);
// Cancel a specific operation associated with the signal set.
ASIO_DECL void cancel_ops_by_key(implementation_type& impl,
void* cancellation_key);
// Start an asynchronous operation to wait for a signal to be delivered.
template <typename Handler, typename IoExecutor>
void async_wait(implementation_type& impl,
Handler& handler, const IoExecutor& io_ex)
{
typename associated_cancellation_slot<Handler>::type slot
= asio::get_associated_cancellation_slot(handler);
// Allocate and construct an operation to wrap the handler.
typedef signal_handler<Handler, IoExecutor> op;
typename op::ptr p = { asio::detail::addressof(handler),
op::ptr::allocate(handler), 0 };
p.p = new (p.v) op(handler, io_ex);
// Optionally register for per-operation cancellation.
if (slot.is_connected())
{
p.p->cancellation_key_ =
&slot.template emplace<signal_op_cancellation>(this, &impl);
}
ASIO_HANDLER_CREATION((scheduler_.context(),
*p.p, "signal_set", &impl, 0, "async_wait"));
start_wait_op(impl, p.p);
p.v = p.p = 0;
}
// Deliver notification that a particular signal occurred.
ASIO_DECL static void deliver_signal(int signal_number);
private:
// Helper function to add a service to the global signal state.
ASIO_DECL static void add_service(signal_set_service* service);
// Helper function to remove a service from the global signal state.
ASIO_DECL static void remove_service(signal_set_service* service);
// Helper function to create the pipe descriptors.
ASIO_DECL static void open_descriptors();
// Helper function to close the pipe descriptors.
ASIO_DECL static void close_descriptors();
// Helper function to start a wait operation.
ASIO_DECL void start_wait_op(implementation_type& impl, signal_op* op);
// Helper class used to implement per-operation cancellation
class signal_op_cancellation
{
public:
signal_op_cancellation(signal_set_service* s, implementation_type* i)
: service_(s),
implementation_(i)
{
}
void operator()(cancellation_type_t type)
{
if (!!(type &
(cancellation_type::terminal
| cancellation_type::partial
| cancellation_type::total)))
{
service_->cancel_ops_by_key(*implementation_, this);
}
}
private:
signal_set_service* service_;
implementation_type* implementation_;
};
// The scheduler used for dispatching handlers.
#if defined(ASIO_HAS_IOCP)
typedef class win_iocp_io_context scheduler_impl;
#else
typedef class scheduler scheduler_impl;
#endif
scheduler_impl& scheduler_;
#if !defined(ASIO_WINDOWS) \
&& !defined(ASIO_WINDOWS_RUNTIME) \
&& !defined(__CYGWIN__)
// The type used for processing pipe readiness notifications.
class pipe_read_op;
# if defined(ASIO_HAS_IO_URING_AS_DEFAULT)
// The io_uring service used for waiting for pipe readiness.
io_uring_service& io_uring_service_;
// The per I/O object data used for the pipe.
io_uring_service::per_io_object_data io_object_data_;
# else // defined(ASIO_HAS_IO_URING_AS_DEFAULT)
// The reactor used for waiting for pipe readiness.
reactor& reactor_;
// The per-descriptor reactor data used for the pipe.
reactor::per_descriptor_data reactor_data_;
# endif // defined(ASIO_HAS_IO_URING_AS_DEFAULT)
#endif // !defined(ASIO_WINDOWS)
// && !defined(ASIO_WINDOWS_RUNTIME)
// && !defined(__CYGWIN__)
// A mapping from signal number to the registered signal sets.
registration* registrations_[max_signal_number];
// Pointers to adjacent services in linked list.
signal_set_service* next_;
signal_set_service* prev_;
};
} // namespace detail
} // namespace asio
#include "asio/detail/pop_options.hpp"
#if defined(ASIO_HEADER_ONLY)
# include "asio/detail/impl/signal_set_service.ipp"
#endif // defined(ASIO_HEADER_ONLY)
#endif // ASIO_DETAIL_SIGNAL_SET_SERVICE_HPP