| // Boost.Signals library |
| |
| // Copyright Douglas Gregor 2001-2004. Use, modification and |
| // distribution is subject to 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) |
| |
| // For more information, see http://www.boost.org |
| |
| #define BOOST_SIGNALS_SOURCE |
| |
| #include <boost/signals/detail/signal_base.hpp> |
| #include <cassert> |
| |
| namespace boost { |
| namespace BOOST_SIGNALS_NAMESPACE { |
| namespace detail { |
| signal_base_impl::signal_base_impl(const compare_type& comp, |
| const any& combiner) |
| : call_depth(0), |
| slots_(comp), |
| combiner_(combiner) |
| { |
| flags.delayed_disconnect = false; |
| flags.clearing = false; |
| } |
| |
| signal_base_impl::~signal_base_impl() |
| { |
| // Set the "clearing" flag to ignore extraneous disconnect requests, |
| // because all slots will be disconnected on destruction anyway. |
| flags.clearing = true; |
| } |
| |
| void signal_base_impl::disconnect_all_slots() |
| { |
| // Do nothing if we're already clearing the slot list |
| if (flags.clearing) |
| return; |
| |
| if (call_depth == 0) { |
| // Clearing the slot list will disconnect all slots automatically |
| temporarily_set_clearing set_clearing(this); |
| slots_.clear(); |
| } |
| else { |
| // We can't actually remove elements from the slot list because there |
| // are still iterators into the slot list that must not be |
| // invalidated by this operation. So just disconnect each slot |
| // without removing it from the slot list. When the call depth does |
| // reach zero, the call list will be cleared. |
| flags.delayed_disconnect = true; |
| temporarily_set_clearing set_clearing(this); |
| for (iterator i = slots_.begin(); i != slots_.end(); ++i) { |
| i->first.disconnect(); |
| } |
| } |
| } |
| |
| connection |
| signal_base_impl:: |
| connect_slot(const any& slot_, |
| const stored_group& name, |
| shared_ptr<slot_base::data_t> data, |
| connect_position at) |
| { |
| // Transfer the burden of ownership to a local, scoped |
| // connection. |
| data->watch_bound_objects.set_controlling(false); |
| scoped_connection safe_connection(data->watch_bound_objects); |
| |
| // Allocate storage for an iterator that will hold the point of |
| // insertion of the slot into the list. This is used to later remove |
| // the slot when it is disconnected. |
| std::auto_ptr<iterator> saved_iter(new iterator); |
| |
| // Add the slot to the list. |
| iterator pos = |
| slots_.insert(name, data->watch_bound_objects, slot_, at); |
| |
| // The assignment operation here absolutely must not throw, which |
| // intuitively makes sense (because any container's insert method |
| // becomes impossible to use in an exception-safe manner without this |
| // assumption), but doesn't appear to be mentioned in the standard. |
| *saved_iter = pos; |
| |
| // Fill out the connection object appropriately. None of these |
| // operations can throw |
| data->watch_bound_objects.get_connection()->signal = this; |
| data->watch_bound_objects.get_connection()->signal_data = |
| saved_iter.release(); |
| data->watch_bound_objects.get_connection()->signal_disconnect = |
| &signal_base_impl::slot_disconnected; |
| |
| // Make the copy of the connection in the list disconnect when it is |
| // destroyed. The local, scoped connection is then released |
| // because ownership has been transferred. |
| pos->first.set_controlling(); |
| return safe_connection.release(); |
| } |
| |
| bool signal_base_impl::empty() const |
| { |
| // Disconnected slots may still be in the list of slots if |
| // a) this is called while slots are being invoked (call_depth > 0) |
| // b) an exception was thrown in remove_disconnected_slots |
| for (iterator i = slots_.begin(); i != slots_.end(); ++i) { |
| if (i->first.connected()) |
| return false; |
| } |
| |
| return true; |
| } |
| |
| std::size_t signal_base_impl::num_slots() const |
| { |
| // Disconnected slots may still be in the list of slots if |
| // a) this is called while slots are being invoked (call_depth > 0) |
| // b) an exception was thrown in remove_disconnected_slots |
| std::size_t count = 0; |
| for (iterator i = slots_.begin(); i != slots_.end(); ++i) { |
| if (i->first.connected()) |
| ++count; |
| } |
| return count; |
| } |
| |
| void signal_base_impl::disconnect(const stored_group& group) |
| { slots_.disconnect(group); } |
| |
| void signal_base_impl::slot_disconnected(void* obj, void* data) |
| { |
| signal_base_impl* self = reinterpret_cast<signal_base_impl*>(obj); |
| |
| // We won't need the slot iterator after this |
| std::auto_ptr<iterator> slot(reinterpret_cast<iterator*>(data)); |
| |
| // If we're flags.clearing, we don't bother updating the list of slots |
| if (!self->flags.clearing) { |
| // If we're in a call, note the fact that a slot has been deleted so |
| // we can come back later to remove the iterator |
| if (self->call_depth > 0) { |
| self->flags.delayed_disconnect = true; |
| } |
| else { |
| // Just remove the slot now, it's safe |
| self->slots_.erase(*slot); |
| } |
| } |
| } |
| |
| void signal_base_impl::remove_disconnected_slots() const |
| { slots_.remove_disconnected_slots(); } |
| |
| call_notification:: |
| call_notification(const shared_ptr<signal_base_impl>& b) : |
| impl(b) |
| { |
| // A call will be made, so increment the call depth as a notification |
| impl->call_depth++; |
| } |
| |
| call_notification::~call_notification() |
| { |
| impl->call_depth--; |
| |
| // If the call depth is zero and we have some slots that have been |
| // disconnected during the calls, remove those slots from the list |
| if (impl->call_depth == 0 && |
| impl->flags.delayed_disconnect) { |
| impl->remove_disconnected_slots(); |
| impl->flags.delayed_disconnect = false; |
| } |
| } |
| |
| signal_base::signal_base(const compare_type& comp, const any& combiner) |
| : impl() |
| { |
| impl.reset(new signal_base_impl(comp, combiner)); |
| } |
| |
| signal_base::~signal_base() |
| { |
| } |
| |
| } // namespace detail |
| } // namespace BOOST_SIGNALS_NAMESPACE |
| } // namespace boost |
| |