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// Copyright (C) 2020-2023 Internet Systems Consortium, Inc. ("ISC")
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
#include <config.h>
#include <asiolink/io_service_signal.h>
#include <exceptions/exceptions.h>
#include <boost/enable_shared_from_this.hpp>
#include <boost/noncopyable.hpp>
#include <boost/asio/signal_set.hpp>
#include <functional>
namespace ph = std::placeholders;
namespace isc {
namespace asiolink {
/// @brief Implementation class of IOSignalSet.
class IOSignalSetImpl : public boost::enable_shared_from_this<IOSignalSetImpl>,
public boost::noncopyable {
public:
/// @brief Constructor.
///
/// @param io_service the process IO service.
/// @param handler the signal handler.
IOSignalSetImpl(IOServicePtr io_service, IOSignalHandler handler);
/// @brief Destructor.
~IOSignalSetImpl();
/// @brief Install the callback on the IO service queue.
void install();
/// @brief Add a signal to the ASIO signal set.
///
/// @param signum the signal number.
void add(int signum);
/// @brief Remove a signal from the ASIO signal set.
///
/// @param signum the signal number.
void remove(int signum);
/// @brief Cancel the remaining installed signal handler callbacks.
void cancel();
private:
/// @brief Extends the lifetime of IOService to avoid heap-use-after-free.
IOServicePtr io_service_;
/// @brief the ASIO signal set.
boost::asio::signal_set signal_set_;
/// @brief the signal handler.
IOSignalHandler handler_;
/// @brief the callback (called on cancel or received signal).
///
/// The callback is installed on the IO service queue and calls
/// the handler if the operation was not aborted.
void callback(const boost::system::error_code& ec, int signum);
};
IOSignalSetImpl::IOSignalSetImpl(IOServicePtr io_service,
IOSignalHandler handler)
: io_service_(io_service),
signal_set_(io_service_->get_io_service()),
handler_(handler) {
}
IOSignalSetImpl::~IOSignalSetImpl() {
handler_ = IOSignalHandler();
}
void
IOSignalSetImpl::cancel() {
signal_set_.cancel();
}
void
IOSignalSetImpl::callback(const boost::system::error_code& ec, int signum) {
if (ec && ec.value() == boost::asio::error::operation_aborted) {
return;
}
install();
if (!ec && (signum > 0)) {
try {
handler_(signum);
} catch (const std::exception& ex) {
}
}
}
void
IOSignalSetImpl::install() {
signal_set_.async_wait(std::bind(&IOSignalSetImpl::callback,
shared_from_this(),
ph::_1, ph::_2));
}
void
IOSignalSetImpl::add(int signum) {
try {
signal_set_.add(signum);
} catch (const boost::system::system_error& ex) {
isc_throw(isc::Unexpected,
"Failed to add signal " << signum << ": " << ex.what());
}
}
void
IOSignalSetImpl::remove(int signum) {
try {
signal_set_.remove(signum);
} catch (const boost::system::system_error& ex) {
isc_throw(isc::Unexpected,
"Failed to remove signal " << signum << ": " << ex.what());
}
}
IOSignalSet::IOSignalSet(IOServicePtr io_service, IOSignalHandler handler) :
impl_(new IOSignalSetImpl(io_service, handler)) {
// It can throw but the error is fatal...
impl_->install();
}
IOSignalSet::~IOSignalSet() {
impl_->cancel();
}
void
IOSignalSet::add(int signum) {
impl_->add(signum);
}
void
IOSignalSet::remove(int signum) {
impl_->remove(signum);
}
} // namespace asiolink
} // namespace isc
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