/Src/Dependencies/Boost/boost/asio/detail/impl/signal_set_service.ipp
http://hadesmem.googlecode.com/ · C++ Header · 592 lines · 467 code · 91 blank · 34 comment · 110 complexity · 0aae66e6182200174514a7560dd6dee0 MD5 · raw file
- //
- // detail/impl/signal_set_service.ipp
- // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- //
- // Copyright (c) 2003-2011 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 BOOST_ASIO_DETAIL_IMPL_SIGNAL_SET_SERVICE_IPP
- #define BOOST_ASIO_DETAIL_IMPL_SIGNAL_SET_SERVICE_IPP
- #if defined(_MSC_VER) && (_MSC_VER >= 1200)
- # pragma once
- #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
- #include <boost/asio/detail/config.hpp>
- #include <cstring>
- #include <boost/asio/detail/reactor.hpp>
- #include <boost/asio/detail/signal_blocker.hpp>
- #include <boost/asio/detail/signal_set_service.hpp>
- #include <boost/asio/detail/static_mutex.hpp>
- #include <boost/asio/detail/push_options.hpp>
- namespace boost {
- namespace asio {
- namespace detail {
- struct signal_state
- {
- // Mutex used for protecting global state.
- static_mutex mutex_;
- // The read end of the pipe used for signal notifications.
- int read_descriptor_;
- // The write end of the pipe used for signal notifications.
- int write_descriptor_;
- // Whether the signal state has been prepared for a fork.
- bool fork_prepared_;
- // The head of a linked list of all signal_set_service instances.
- class signal_set_service* service_list_;
- // A count of the number of objects that are registered for each signal.
- std::size_t registration_count_[max_signal_number];
- };
- signal_state* get_signal_state()
- {
- static signal_state state = {
- BOOST_ASIO_STATIC_MUTEX_INIT, -1, -1, false, 0, { 0 } };
- return &state;
- }
- void asio_signal_handler(int signal_number)
- {
- #if defined(BOOST_WINDOWS) || defined(__CYGWIN__)
- signal_set_service::deliver_signal(signal_number);
- #else // defined(BOOST_WINDOWS) || defined(__CYGWIN__)
- int saved_errno = errno;
- signal_state* state = get_signal_state();
- int result = ::write(state->write_descriptor_,
- &signal_number, sizeof(signal_number));
- (void)result;
- errno = saved_errno;
- #endif // defined(BOOST_WINDOWS) || defined(__CYGWIN__)
- #if defined(BOOST_ASIO_HAS_SIGNAL) && !defined(BOOST_ASIO_HAS_SIGACTION)
- signal(signal_number, asio_signal_handler);
- #endif // defined(BOOST_ASIO_HAS_SIGNAL) && !defined(BOOST_ASIO_HAS_SIGACTION)
- }
- #if !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
- class signal_set_service::pipe_read_op : public reactor_op
- {
- public:
- pipe_read_op()
- : reactor_op(&pipe_read_op::do_perform, pipe_read_op::do_complete)
- {
- }
- static bool do_perform(reactor_op*)
- {
- signal_state* state = get_signal_state();
- int fd = state->read_descriptor_;
- int signal_number = 0;
- while (::read(fd, &signal_number, sizeof(int)) == sizeof(int))
- if (signal_number >= 0 && signal_number < max_signal_number)
- signal_set_service::deliver_signal(signal_number);
- return false;
- }
- static void do_complete(io_service_impl* /*owner*/, operation* base,
- boost::system::error_code /*ec*/, std::size_t /*bytes_transferred*/)
- {
- pipe_read_op* o(static_cast<pipe_read_op*>(base));
- delete o;
- }
- };
- #endif // !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
- signal_set_service::signal_set_service(
- boost::asio::io_service& io_service)
- : io_service_(boost::asio::use_service<io_service_impl>(io_service)),
- #if !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
- reactor_(boost::asio::use_service<reactor>(io_service)),
- #endif // !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
- next_(0),
- prev_(0)
- {
- get_signal_state()->mutex_.init();
- #if !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
- reactor_.init_task();
- #endif // !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
- for (int i = 0; i < max_signal_number; ++i)
- registrations_[i] = 0;
- add_service(this);
- }
- signal_set_service::~signal_set_service()
- {
- remove_service(this);
- }
- void signal_set_service::shutdown_service()
- {
- remove_service(this);
- op_queue<operation> ops;
- for (int i = 0; i < max_signal_number; ++i)
- {
- registration* reg = registrations_[i];
- while (reg)
- {
- ops.push(*reg->queue_);
- reg = reg->next_in_table_;
- }
- }
- io_service_.abandon_operations(ops);
- }
- void signal_set_service::fork_service(
- boost::asio::io_service::fork_event fork_ev)
- {
- #if !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
- signal_state* state = get_signal_state();
- static_mutex::scoped_lock lock(state->mutex_);
- switch (fork_ev)
- {
- case boost::asio::io_service::fork_prepare:
- reactor_.deregister_internal_descriptor(
- state->read_descriptor_, reactor_data_);
- state->fork_prepared_ = true;
- break;
- case boost::asio::io_service::fork_parent:
- state->fork_prepared_ = false;
- reactor_.register_internal_descriptor(reactor::read_op,
- state->read_descriptor_, reactor_data_, new pipe_read_op);
- break;
- case boost::asio::io_service::fork_child:
- if (state->fork_prepared_)
- {
- boost::asio::detail::signal_blocker blocker;
- close_descriptors();
- open_descriptors();
- state->fork_prepared_ = false;
- }
- reactor_.register_internal_descriptor(reactor::read_op,
- state->read_descriptor_, reactor_data_, new pipe_read_op);
- break;
- default:
- break;
- }
- #else // !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
- (void)fork_ev;
- #endif // !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
- }
- void signal_set_service::construct(
- signal_set_service::implementation_type& impl)
- {
- impl.signals_ = 0;
- }
- void signal_set_service::destroy(
- signal_set_service::implementation_type& impl)
- {
- boost::system::error_code ignored_ec;
- clear(impl, ignored_ec);
- cancel(impl, ignored_ec);
- }
- boost::system::error_code signal_set_service::add(
- signal_set_service::implementation_type& impl,
- int signal_number, boost::system::error_code& ec)
- {
- // Check that the signal number is valid.
- if (signal_number < 0 || signal_number > max_signal_number)
- {
- ec = boost::asio::error::invalid_argument;
- return ec;
- }
- signal_state* state = get_signal_state();
- static_mutex::scoped_lock lock(state->mutex_);
- // Find the appropriate place to insert the registration.
- registration** insertion_point = &impl.signals_;
- registration* next = impl.signals_;
- while (next && next->signal_number_ < signal_number)
- {
- insertion_point = &next->next_in_set_;
- next = next->next_in_set_;
- }
- // Only do something if the signal is not already registered.
- if (next == 0 || next->signal_number_ != signal_number)
- {
- registration* new_registration = new registration;
- #if defined(BOOST_ASIO_HAS_SIGNAL) || defined(BOOST_ASIO_HAS_SIGACTION)
- // Register for the signal if we're the first.
- if (state->registration_count_[signal_number] == 0)
- {
- # if defined(BOOST_ASIO_HAS_SIGACTION)
- using namespace std; // For memset.
- struct sigaction sa;
- memset(&sa, 0, sizeof(sa));
- sa.sa_handler = asio_signal_handler;
- sigfillset(&sa.sa_mask);
- if (::sigaction(signal_number, &sa, 0) == -1)
- # else // defined(BOOST_ASIO_HAS_SIGACTION)
- if (::signal(signal_number, asio_signal_handler) == SIG_ERR)
- # endif // defined(BOOST_ASIO_HAS_SIGACTION)
- {
- # if defined(BOOST_WINDOWS) || defined(__CYGWIN__)
- ec = boost::asio::error::invalid_argument;
- # else // defined(BOOST_WINDOWS) || defined(__CYGWIN__)
- ec = boost::system::error_code(errno,
- boost::asio::error::get_system_category());
- # endif // defined(BOOST_WINDOWS) || defined(__CYGWIN__)
- delete new_registration;
- return ec;
- }
- }
- #endif // defined(BOOST_ASIO_HAS_SIGNAL) || defined(BOOST_ASIO_HAS_SIGACTION)
- // Record the new registration in the set.
- new_registration->signal_number_ = signal_number;
- new_registration->queue_ = &impl.queue_;
- new_registration->next_in_set_ = next;
- *insertion_point = new_registration;
- // Insert registration into the registration table.
- new_registration->next_in_table_ = registrations_[signal_number];
- if (registrations_[signal_number])
- registrations_[signal_number]->prev_in_table_ = new_registration;
- registrations_[signal_number] = new_registration;
- ++state->registration_count_[signal_number];
- }
- ec = boost::system::error_code();
- return ec;
- }
- boost::system::error_code signal_set_service::remove(
- signal_set_service::implementation_type& impl,
- int signal_number, boost::system::error_code& ec)
- {
- // Check that the signal number is valid.
- if (signal_number < 0 || signal_number > max_signal_number)
- {
- ec = boost::asio::error::invalid_argument;
- return ec;
- }
- signal_state* state = get_signal_state();
- static_mutex::scoped_lock lock(state->mutex_);
- // Find the signal number in the list of registrations.
- registration** deletion_point = &impl.signals_;
- registration* reg = impl.signals_;
- while (reg && reg->signal_number_ < signal_number)
- {
- deletion_point = ®->next_in_set_;
- reg = reg->next_in_set_;
- }
- if (reg != 0 && reg->signal_number_ == signal_number)
- {
- #if defined(BOOST_ASIO_HAS_SIGNAL) || defined(BOOST_ASIO_HAS_SIGACTION)
- // Set signal handler back to the default if we're the last.
- if (state->registration_count_[signal_number] == 1)
- {
- # if defined(BOOST_ASIO_HAS_SIGACTION)
- using namespace std; // For memset.
- struct sigaction sa;
- memset(&sa, 0, sizeof(sa));
- sa.sa_handler = SIG_DFL;
- if (::sigaction(signal_number, &sa, 0) == -1)
- # else // defined(BOOST_ASIO_HAS_SIGACTION)
- if (::signal(signal_number, SIG_DFL) == SIG_ERR)
- # endif // defined(BOOST_ASIO_HAS_SIGACTION)
- {
- # if defined(BOOST_WINDOWS) || defined(__CYGWIN__)
- ec = boost::asio::error::invalid_argument;
- # else // defined(BOOST_WINDOWS) || defined(__CYGWIN__)
- ec = boost::system::error_code(errno,
- boost::asio::error::get_system_category());
- # endif // defined(BOOST_WINDOWS) || defined(__CYGWIN__)
- return ec;
- }
- }
- #endif // defined(BOOST_ASIO_HAS_SIGNAL) || defined(BOOST_ASIO_HAS_SIGACTION)
- // Remove the registration from the set.
- *deletion_point = reg->next_in_set_;
- // Remove the registration from the registration table.
- if (registrations_[signal_number] == reg)
- registrations_[signal_number] = reg->next_in_table_;
- if (reg->prev_in_table_)
- reg->prev_in_table_->next_in_table_ = reg->next_in_table_;
- if (reg->next_in_table_)
- reg->next_in_table_->prev_in_table_ = reg->prev_in_table_;
- --state->registration_count_[signal_number];
- delete reg;
- }
- ec = boost::system::error_code();
- return ec;
- }
- boost::system::error_code signal_set_service::clear(
- signal_set_service::implementation_type& impl,
- boost::system::error_code& ec)
- {
- signal_state* state = get_signal_state();
- static_mutex::scoped_lock lock(state->mutex_);
- while (registration* reg = impl.signals_)
- {
- #if defined(BOOST_ASIO_HAS_SIGNAL) || defined(BOOST_ASIO_HAS_SIGACTION)
- // Set signal handler back to the default if we're the last.
- if (state->registration_count_[reg->signal_number_] == 1)
- {
- # if defined(BOOST_ASIO_HAS_SIGACTION)
- using namespace std; // For memset.
- struct sigaction sa;
- memset(&sa, 0, sizeof(sa));
- sa.sa_handler = SIG_DFL;
- if (::sigaction(reg->signal_number_, &sa, 0) == -1)
- # else // defined(BOOST_ASIO_HAS_SIGACTION)
- if (::signal(reg->signal_number_, SIG_DFL) == SIG_ERR)
- # endif // defined(BOOST_ASIO_HAS_SIGACTION)
- {
- # if defined(BOOST_WINDOWS) || defined(__CYGWIN__)
- ec = boost::asio::error::invalid_argument;
- # else // defined(BOOST_WINDOWS) || defined(__CYGWIN__)
- ec = boost::system::error_code(errno,
- boost::asio::error::get_system_category());
- # endif // defined(BOOST_WINDOWS) || defined(__CYGWIN__)
- return ec;
- }
- }
- #endif // defined(BOOST_ASIO_HAS_SIGNAL) || defined(BOOST_ASIO_HAS_SIGACTION)
- // Remove the registration from the registration table.
- if (registrations_[reg->signal_number_] == reg)
- registrations_[reg->signal_number_] = reg->next_in_table_;
- if (reg->prev_in_table_)
- reg->prev_in_table_->next_in_table_ = reg->next_in_table_;
- if (reg->next_in_table_)
- reg->next_in_table_->prev_in_table_ = reg->prev_in_table_;
- --state->registration_count_[reg->signal_number_];
- impl.signals_ = reg->next_in_set_;
- delete reg;
- }
- ec = boost::system::error_code();
- return ec;
- }
- boost::system::error_code signal_set_service::cancel(
- signal_set_service::implementation_type& impl,
- boost::system::error_code& ec)
- {
- BOOST_ASIO_HANDLER_OPERATION(("signal_set", &impl, "cancel"));
- op_queue<operation> ops;
- {
- signal_state* state = get_signal_state();
- static_mutex::scoped_lock lock(state->mutex_);
- while (signal_op* op = impl.queue_.front())
- {
- op->ec_ = boost::asio::error::operation_aborted;
- impl.queue_.pop();
- ops.push(op);
- }
- }
- io_service_.post_deferred_completions(ops);
- ec = boost::system::error_code();
- return ec;
- }
- void signal_set_service::deliver_signal(int signal_number)
- {
- signal_state* state = get_signal_state();
- static_mutex::scoped_lock lock(state->mutex_);
- signal_set_service* service = state->service_list_;
- while (service)
- {
- op_queue<operation> ops;
- registration* reg = service->registrations_[signal_number];
- while (reg)
- {
- if (reg->queue_->empty())
- {
- ++reg->undelivered_;
- }
- else
- {
- while (signal_op* op = reg->queue_->front())
- {
- op->signal_number_ = signal_number;
- reg->queue_->pop();
- ops.push(op);
- }
- }
- reg = reg->next_in_table_;
- }
- service->io_service_.post_deferred_completions(ops);
- service = service->next_;
- }
- }
- void signal_set_service::add_service(signal_set_service* service)
- {
- signal_state* state = get_signal_state();
- static_mutex::scoped_lock lock(state->mutex_);
- #if !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
- // If this is the first service to be created, open a new pipe.
- if (state->service_list_ == 0)
- open_descriptors();
- #endif // !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
- // Insert service into linked list of all services.
- service->next_ = state->service_list_;
- service->prev_ = 0;
- if (state->service_list_)
- state->service_list_->prev_ = service;
- state->service_list_ = service;
- #if !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
- // Register for pipe readiness notifications.
- service->reactor_.register_internal_descriptor(reactor::read_op,
- state->read_descriptor_, service->reactor_data_, new pipe_read_op);
- #endif // !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
- }
- void signal_set_service::remove_service(signal_set_service* service)
- {
- signal_state* state = get_signal_state();
- static_mutex::scoped_lock lock(state->mutex_);
- if (service->next_ || service->prev_ || state->service_list_ == service)
- {
- #if !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
- // Disable the pipe readiness notifications.
- service->reactor_.deregister_descriptor(
- state->read_descriptor_, service->reactor_data_, false);
- #endif // !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
- // Remove service from linked list of all services.
- if (state->service_list_ == service)
- state->service_list_ = service->next_;
- if (service->prev_)
- service->prev_->next_ = service->next_;
- if (service->next_)
- service->next_->prev_= service->prev_;
- service->next_ = 0;
- service->prev_ = 0;
- #if !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
- // If this is the last service to be removed, close the pipe.
- if (state->service_list_ == 0)
- close_descriptors();
- #endif // !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
- }
- }
- void signal_set_service::open_descriptors()
- {
- #if !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
- signal_state* state = get_signal_state();
- int pipe_fds[2];
- if (::pipe(pipe_fds) == 0)
- {
- state->read_descriptor_ = pipe_fds[0];
- ::fcntl(state->read_descriptor_, F_SETFL, O_NONBLOCK);
- state->write_descriptor_ = pipe_fds[1];
- ::fcntl(state->write_descriptor_, F_SETFL, O_NONBLOCK);
- #if defined(FD_CLOEXEC)
- ::fcntl(state->read_descriptor_, F_SETFD, FD_CLOEXEC);
- ::fcntl(state->write_descriptor_, F_SETFD, FD_CLOEXEC);
- #endif // defined(FD_CLOEXEC)
- }
- else
- {
- boost::system::error_code ec(errno,
- boost::asio::error::get_system_category());
- boost::asio::detail::throw_error(ec, "signal_set_service pipe");
- }
- #endif // !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
- }
- void signal_set_service::close_descriptors()
- {
- #if !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
- signal_state* state = get_signal_state();
- if (state->read_descriptor_ != -1)
- ::close(state->read_descriptor_);
- state->read_descriptor_ = -1;
- if (state->write_descriptor_ != -1)
- ::close(state->write_descriptor_);
- state->write_descriptor_ = -1;
- #endif // !defined(BOOST_WINDOWS) && !defined(__CYGWIN__)
- }
- void signal_set_service::start_wait_op(
- signal_set_service::implementation_type& impl, signal_op* op)
- {
- io_service_.work_started();
- signal_state* state = get_signal_state();
- static_mutex::scoped_lock lock(state->mutex_);
- registration* reg = impl.signals_;
- while (reg)
- {
- if (reg->undelivered_ > 0)
- {
- --reg->undelivered_;
- io_service_.post_deferred_completion(op);
- return;
- }
- reg = reg->next_in_set_;
- }
- impl.queue_.push(op);
- }
- } // namespace detail
- } // namespace asio
- } // namespace boost
- #include <boost/asio/detail/pop_options.hpp>
- #endif // BOOST_ASIO_DETAIL_IMPL_SIGNAL_SET_SERVICE_IPP