2 // detail/impl/signal_set_service.ipp
3 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
5 // Copyright (c) 2003-2016 Christopher M. Kohlhoff (chris at kohlhoff dot com)
7 // Distributed under the Boost Software License, Version 1.0. (See accompanying
8 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
11 #ifndef BOOST_ASIO_DETAIL_IMPL_SIGNAL_SET_SERVICE_IPP
12 #define BOOST_ASIO_DETAIL_IMPL_SIGNAL_SET_SERVICE_IPP
14 #if defined(_MSC_VER) && (_MSC_VER >= 1200)
16 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
18 #include <boost/asio/detail/config.hpp>
21 #include <boost/asio/detail/reactor.hpp>
22 #include <boost/asio/detail/signal_blocker.hpp>
23 #include <boost/asio/detail/signal_set_service.hpp>
24 #include <boost/asio/detail/static_mutex.hpp>
26 #include <boost/asio/detail/push_options.hpp>
34 // Mutex used for protecting global state.
37 // The read end of the pipe used for signal notifications.
40 // The write end of the pipe used for signal notifications.
41 int write_descriptor_;
43 // Whether the signal state has been prepared for a fork.
46 // The head of a linked list of all signal_set_service instances.
47 class signal_set_service* service_list_;
49 // A count of the number of objects that are registered for each signal.
50 std::size_t registration_count_[max_signal_number];
53 signal_state* get_signal_state()
55 static signal_state state = {
56 BOOST_ASIO_STATIC_MUTEX_INIT, -1, -1, false, 0, { 0 } };
60 void boost_asio_signal_handler(int signal_number)
62 #if defined(BOOST_ASIO_WINDOWS) \
63 || defined(BOOST_ASIO_WINDOWS_RUNTIME) \
64 || defined(__CYGWIN__)
65 signal_set_service::deliver_signal(signal_number);
66 #else // defined(BOOST_ASIO_WINDOWS)
67 // || defined(BOOST_ASIO_WINDOWS_RUNTIME)
68 // || defined(__CYGWIN__)
69 int saved_errno = errno;
70 signal_state* state = get_signal_state();
71 signed_size_type result = ::write(state->write_descriptor_,
72 &signal_number, sizeof(signal_number));
75 #endif // defined(BOOST_ASIO_WINDOWS)
76 // || defined(BOOST_ASIO_WINDOWS_RUNTIME)
77 // || defined(__CYGWIN__)
79 #if defined(BOOST_ASIO_HAS_SIGNAL) && !defined(BOOST_ASIO_HAS_SIGACTION)
80 ::signal(signal_number, boost_asio_signal_handler);
81 #endif // defined(BOOST_ASIO_HAS_SIGNAL) && !defined(BOOST_ASIO_HAS_SIGACTION)
84 #if !defined(BOOST_ASIO_WINDOWS) \
85 && !defined(BOOST_ASIO_WINDOWS_RUNTIME) \
86 && !defined(__CYGWIN__)
87 class signal_set_service::pipe_read_op : public reactor_op
91 : reactor_op(&pipe_read_op::do_perform, pipe_read_op::do_complete)
95 static bool do_perform(reactor_op*)
97 signal_state* state = get_signal_state();
99 int fd = state->read_descriptor_;
100 int signal_number = 0;
101 while (::read(fd, &signal_number, sizeof(int)) == sizeof(int))
102 if (signal_number >= 0 && signal_number < max_signal_number)
103 signal_set_service::deliver_signal(signal_number);
108 static void do_complete(io_service_impl* /*owner*/, operation* base,
109 const boost::system::error_code& /*ec*/,
110 std::size_t /*bytes_transferred*/)
112 pipe_read_op* o(static_cast<pipe_read_op*>(base));
116 #endif // !defined(BOOST_ASIO_WINDOWS)
117 // && !defined(BOOST_ASIO_WINDOWS_RUNTIME)
118 // && !defined(__CYGWIN__)
120 signal_set_service::signal_set_service(
121 boost::asio::io_service& io_service)
122 : io_service_(boost::asio::use_service<io_service_impl>(io_service)),
123 #if !defined(BOOST_ASIO_WINDOWS) \
124 && !defined(BOOST_ASIO_WINDOWS_RUNTIME) \
125 && !defined(__CYGWIN__)
126 reactor_(boost::asio::use_service<reactor>(io_service)),
127 #endif // !defined(BOOST_ASIO_WINDOWS)
128 // && !defined(BOOST_ASIO_WINDOWS_RUNTIME)
129 // && !defined(__CYGWIN__)
133 get_signal_state()->mutex_.init();
135 #if !defined(BOOST_ASIO_WINDOWS) \
136 && !defined(BOOST_ASIO_WINDOWS_RUNTIME) \
137 && !defined(__CYGWIN__)
138 reactor_.init_task();
139 #endif // !defined(BOOST_ASIO_WINDOWS)
140 // && !defined(BOOST_ASIO_WINDOWS_RUNTIME)
141 // && !defined(__CYGWIN__)
143 for (int i = 0; i < max_signal_number; ++i)
144 registrations_[i] = 0;
149 signal_set_service::~signal_set_service()
151 remove_service(this);
154 void signal_set_service::shutdown_service()
156 remove_service(this);
158 op_queue<operation> ops;
160 for (int i = 0; i < max_signal_number; ++i)
162 registration* reg = registrations_[i];
165 ops.push(*reg->queue_);
166 reg = reg->next_in_table_;
170 io_service_.abandon_operations(ops);
173 void signal_set_service::fork_service(
174 boost::asio::io_service::fork_event fork_ev)
176 #if !defined(BOOST_ASIO_WINDOWS) \
177 && !defined(BOOST_ASIO_WINDOWS_RUNTIME) \
178 && !defined(__CYGWIN__)
179 signal_state* state = get_signal_state();
180 static_mutex::scoped_lock lock(state->mutex_);
184 case boost::asio::io_service::fork_prepare:
186 int read_descriptor = state->read_descriptor_;
187 state->fork_prepared_ = true;
189 reactor_.deregister_internal_descriptor(read_descriptor, reactor_data_);
192 case boost::asio::io_service::fork_parent:
193 if (state->fork_prepared_)
195 int read_descriptor = state->read_descriptor_;
196 state->fork_prepared_ = false;
198 reactor_.register_internal_descriptor(reactor::read_op,
199 read_descriptor, reactor_data_, new pipe_read_op);
202 case boost::asio::io_service::fork_child:
203 if (state->fork_prepared_)
205 boost::asio::detail::signal_blocker blocker;
208 int read_descriptor = state->read_descriptor_;
209 state->fork_prepared_ = false;
211 reactor_.register_internal_descriptor(reactor::read_op,
212 read_descriptor, reactor_data_, new pipe_read_op);
218 #else // !defined(BOOST_ASIO_WINDOWS)
219 // && !defined(BOOST_ASIO_WINDOWS_RUNTIME)
220 // && !defined(__CYGWIN__)
222 #endif // !defined(BOOST_ASIO_WINDOWS)
223 // && !defined(BOOST_ASIO_WINDOWS_RUNTIME)
224 // && !defined(__CYGWIN__)
227 void signal_set_service::construct(
228 signal_set_service::implementation_type& impl)
233 void signal_set_service::destroy(
234 signal_set_service::implementation_type& impl)
236 boost::system::error_code ignored_ec;
237 clear(impl, ignored_ec);
238 cancel(impl, ignored_ec);
241 boost::system::error_code signal_set_service::add(
242 signal_set_service::implementation_type& impl,
243 int signal_number, boost::system::error_code& ec)
245 // Check that the signal number is valid.
246 if (signal_number < 0 || signal_number >= max_signal_number)
248 ec = boost::asio::error::invalid_argument;
252 signal_state* state = get_signal_state();
253 static_mutex::scoped_lock lock(state->mutex_);
255 // Find the appropriate place to insert the registration.
256 registration** insertion_point = &impl.signals_;
257 registration* next = impl.signals_;
258 while (next && next->signal_number_ < signal_number)
260 insertion_point = &next->next_in_set_;
261 next = next->next_in_set_;
264 // Only do something if the signal is not already registered.
265 if (next == 0 || next->signal_number_ != signal_number)
267 registration* new_registration = new registration;
269 #if defined(BOOST_ASIO_HAS_SIGNAL) || defined(BOOST_ASIO_HAS_SIGACTION)
270 // Register for the signal if we're the first.
271 if (state->registration_count_[signal_number] == 0)
273 # if defined(BOOST_ASIO_HAS_SIGACTION)
274 using namespace std; // For memset.
276 memset(&sa, 0, sizeof(sa));
277 sa.sa_handler = boost_asio_signal_handler;
278 sigfillset(&sa.sa_mask);
279 if (::sigaction(signal_number, &sa, 0) == -1)
280 # else // defined(BOOST_ASIO_HAS_SIGACTION)
281 if (::signal(signal_number, boost_asio_signal_handler) == SIG_ERR)
282 # endif // defined(BOOST_ASIO_HAS_SIGACTION)
284 # if defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
285 ec = boost::asio::error::invalid_argument;
286 # else // defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
287 ec = boost::system::error_code(errno,
288 boost::asio::error::get_system_category());
289 # endif // defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
290 delete new_registration;
294 #endif // defined(BOOST_ASIO_HAS_SIGNAL) || defined(BOOST_ASIO_HAS_SIGACTION)
296 // Record the new registration in the set.
297 new_registration->signal_number_ = signal_number;
298 new_registration->queue_ = &impl.queue_;
299 new_registration->next_in_set_ = next;
300 *insertion_point = new_registration;
302 // Insert registration into the registration table.
303 new_registration->next_in_table_ = registrations_[signal_number];
304 if (registrations_[signal_number])
305 registrations_[signal_number]->prev_in_table_ = new_registration;
306 registrations_[signal_number] = new_registration;
308 ++state->registration_count_[signal_number];
311 ec = boost::system::error_code();
315 boost::system::error_code signal_set_service::remove(
316 signal_set_service::implementation_type& impl,
317 int signal_number, boost::system::error_code& ec)
319 // Check that the signal number is valid.
320 if (signal_number < 0 || signal_number >= max_signal_number)
322 ec = boost::asio::error::invalid_argument;
326 signal_state* state = get_signal_state();
327 static_mutex::scoped_lock lock(state->mutex_);
329 // Find the signal number in the list of registrations.
330 registration** deletion_point = &impl.signals_;
331 registration* reg = impl.signals_;
332 while (reg && reg->signal_number_ < signal_number)
334 deletion_point = ®->next_in_set_;
335 reg = reg->next_in_set_;
338 if (reg != 0 && reg->signal_number_ == signal_number)
340 #if defined(BOOST_ASIO_HAS_SIGNAL) || defined(BOOST_ASIO_HAS_SIGACTION)
341 // Set signal handler back to the default if we're the last.
342 if (state->registration_count_[signal_number] == 1)
344 # if defined(BOOST_ASIO_HAS_SIGACTION)
345 using namespace std; // For memset.
347 memset(&sa, 0, sizeof(sa));
348 sa.sa_handler = SIG_DFL;
349 if (::sigaction(signal_number, &sa, 0) == -1)
350 # else // defined(BOOST_ASIO_HAS_SIGACTION)
351 if (::signal(signal_number, SIG_DFL) == SIG_ERR)
352 # endif // defined(BOOST_ASIO_HAS_SIGACTION)
354 # if defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
355 ec = boost::asio::error::invalid_argument;
356 # else // defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
357 ec = boost::system::error_code(errno,
358 boost::asio::error::get_system_category());
359 # endif // defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
363 #endif // defined(BOOST_ASIO_HAS_SIGNAL) || defined(BOOST_ASIO_HAS_SIGACTION)
365 // Remove the registration from the set.
366 *deletion_point = reg->next_in_set_;
368 // Remove the registration from the registration table.
369 if (registrations_[signal_number] == reg)
370 registrations_[signal_number] = reg->next_in_table_;
371 if (reg->prev_in_table_)
372 reg->prev_in_table_->next_in_table_ = reg->next_in_table_;
373 if (reg->next_in_table_)
374 reg->next_in_table_->prev_in_table_ = reg->prev_in_table_;
376 --state->registration_count_[signal_number];
381 ec = boost::system::error_code();
385 boost::system::error_code signal_set_service::clear(
386 signal_set_service::implementation_type& impl,
387 boost::system::error_code& ec)
389 signal_state* state = get_signal_state();
390 static_mutex::scoped_lock lock(state->mutex_);
392 while (registration* reg = impl.signals_)
394 #if defined(BOOST_ASIO_HAS_SIGNAL) || defined(BOOST_ASIO_HAS_SIGACTION)
395 // Set signal handler back to the default if we're the last.
396 if (state->registration_count_[reg->signal_number_] == 1)
398 # if defined(BOOST_ASIO_HAS_SIGACTION)
399 using namespace std; // For memset.
401 memset(&sa, 0, sizeof(sa));
402 sa.sa_handler = SIG_DFL;
403 if (::sigaction(reg->signal_number_, &sa, 0) == -1)
404 # else // defined(BOOST_ASIO_HAS_SIGACTION)
405 if (::signal(reg->signal_number_, SIG_DFL) == SIG_ERR)
406 # endif // defined(BOOST_ASIO_HAS_SIGACTION)
408 # if defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
409 ec = boost::asio::error::invalid_argument;
410 # else // defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
411 ec = boost::system::error_code(errno,
412 boost::asio::error::get_system_category());
413 # endif // defined(BOOST_ASIO_WINDOWS) || defined(__CYGWIN__)
417 #endif // defined(BOOST_ASIO_HAS_SIGNAL) || defined(BOOST_ASIO_HAS_SIGACTION)
419 // Remove the registration from the registration table.
420 if (registrations_[reg->signal_number_] == reg)
421 registrations_[reg->signal_number_] = reg->next_in_table_;
422 if (reg->prev_in_table_)
423 reg->prev_in_table_->next_in_table_ = reg->next_in_table_;
424 if (reg->next_in_table_)
425 reg->next_in_table_->prev_in_table_ = reg->prev_in_table_;
427 --state->registration_count_[reg->signal_number_];
429 impl.signals_ = reg->next_in_set_;
433 ec = boost::system::error_code();
437 boost::system::error_code signal_set_service::cancel(
438 signal_set_service::implementation_type& impl,
439 boost::system::error_code& ec)
441 BOOST_ASIO_HANDLER_OPERATION(("signal_set", &impl, "cancel"));
443 op_queue<operation> ops;
445 signal_state* state = get_signal_state();
446 static_mutex::scoped_lock lock(state->mutex_);
448 while (signal_op* op = impl.queue_.front())
450 op->ec_ = boost::asio::error::operation_aborted;
456 io_service_.post_deferred_completions(ops);
458 ec = boost::system::error_code();
462 void signal_set_service::deliver_signal(int signal_number)
464 signal_state* state = get_signal_state();
465 static_mutex::scoped_lock lock(state->mutex_);
467 signal_set_service* service = state->service_list_;
470 op_queue<operation> ops;
472 registration* reg = service->registrations_[signal_number];
475 if (reg->queue_->empty())
481 while (signal_op* op = reg->queue_->front())
483 op->signal_number_ = signal_number;
489 reg = reg->next_in_table_;
492 service->io_service_.post_deferred_completions(ops);
494 service = service->next_;
498 void signal_set_service::add_service(signal_set_service* service)
500 signal_state* state = get_signal_state();
501 static_mutex::scoped_lock lock(state->mutex_);
503 #if !defined(BOOST_ASIO_WINDOWS) && !defined(__CYGWIN__)
504 // If this is the first service to be created, open a new pipe.
505 if (state->service_list_ == 0)
507 #endif // !defined(BOOST_ASIO_WINDOWS) && !defined(__CYGWIN__)
509 // Insert service into linked list of all services.
510 service->next_ = state->service_list_;
512 if (state->service_list_)
513 state->service_list_->prev_ = service;
514 state->service_list_ = service;
516 #if !defined(BOOST_ASIO_WINDOWS) \
517 && !defined(BOOST_ASIO_WINDOWS_RUNTIME) \
518 && !defined(__CYGWIN__)
519 // Register for pipe readiness notifications.
520 int read_descriptor = state->read_descriptor_;
522 service->reactor_.register_internal_descriptor(reactor::read_op,
523 read_descriptor, service->reactor_data_, new pipe_read_op);
524 #endif // !defined(BOOST_ASIO_WINDOWS)
525 // && !defined(BOOST_ASIO_WINDOWS_RUNTIME)
526 // && !defined(__CYGWIN__)
529 void signal_set_service::remove_service(signal_set_service* service)
531 signal_state* state = get_signal_state();
532 static_mutex::scoped_lock lock(state->mutex_);
534 if (service->next_ || service->prev_ || state->service_list_ == service)
536 #if !defined(BOOST_ASIO_WINDOWS) \
537 && !defined(BOOST_ASIO_WINDOWS_RUNTIME) \
538 && !defined(__CYGWIN__)
539 // Disable the pipe readiness notifications.
540 int read_descriptor = state->read_descriptor_;
542 service->reactor_.deregister_descriptor(
543 read_descriptor, service->reactor_data_, false);
545 #endif // !defined(BOOST_ASIO_WINDOWS)
546 // && !defined(BOOST_ASIO_WINDOWS_RUNTIME)
547 // && !defined(__CYGWIN__)
549 // Remove service from linked list of all services.
550 if (state->service_list_ == service)
551 state->service_list_ = service->next_;
553 service->prev_->next_ = service->next_;
555 service->next_->prev_= service->prev_;
559 #if !defined(BOOST_ASIO_WINDOWS) && !defined(__CYGWIN__)
560 // If this is the last service to be removed, close the pipe.
561 if (state->service_list_ == 0)
563 #endif // !defined(BOOST_ASIO_WINDOWS) && !defined(__CYGWIN__)
567 void signal_set_service::open_descriptors()
569 #if !defined(BOOST_ASIO_WINDOWS) \
570 && !defined(BOOST_ASIO_WINDOWS_RUNTIME) \
571 && !defined(__CYGWIN__)
572 signal_state* state = get_signal_state();
575 if (::pipe(pipe_fds) == 0)
577 state->read_descriptor_ = pipe_fds[0];
578 ::fcntl(state->read_descriptor_, F_SETFL, O_NONBLOCK);
580 state->write_descriptor_ = pipe_fds[1];
581 ::fcntl(state->write_descriptor_, F_SETFL, O_NONBLOCK);
583 #if defined(FD_CLOEXEC)
584 ::fcntl(state->read_descriptor_, F_SETFD, FD_CLOEXEC);
585 ::fcntl(state->write_descriptor_, F_SETFD, FD_CLOEXEC);
586 #endif // defined(FD_CLOEXEC)
590 boost::system::error_code ec(errno,
591 boost::asio::error::get_system_category());
592 boost::asio::detail::throw_error(ec, "signal_set_service pipe");
594 #endif // !defined(BOOST_ASIO_WINDOWS)
595 // && !defined(BOOST_ASIO_WINDOWS_RUNTIME)
596 // && !defined(__CYGWIN__)
599 void signal_set_service::close_descriptors()
601 #if !defined(BOOST_ASIO_WINDOWS) \
602 && !defined(BOOST_ASIO_WINDOWS_RUNTIME) \
603 && !defined(__CYGWIN__)
604 signal_state* state = get_signal_state();
606 if (state->read_descriptor_ != -1)
607 ::close(state->read_descriptor_);
608 state->read_descriptor_ = -1;
610 if (state->write_descriptor_ != -1)
611 ::close(state->write_descriptor_);
612 state->write_descriptor_ = -1;
613 #endif // !defined(BOOST_ASIO_WINDOWS)
614 // && !defined(BOOST_ASIO_WINDOWS_RUNTIME)
615 // && !defined(__CYGWIN__)
618 void signal_set_service::start_wait_op(
619 signal_set_service::implementation_type& impl, signal_op* op)
621 io_service_.work_started();
623 signal_state* state = get_signal_state();
624 static_mutex::scoped_lock lock(state->mutex_);
626 registration* reg = impl.signals_;
629 if (reg->undelivered_ > 0)
632 op->signal_number_ = reg->signal_number_;
633 io_service_.post_deferred_completion(op);
637 reg = reg->next_in_set_;
640 impl.queue_.push(op);
643 } // namespace detail
647 #include <boost/asio/detail/pop_options.hpp>
649 #endif // BOOST_ASIO_DETAIL_IMPL_SIGNAL_SET_SERVICE_IPP