comparison DEPENDENCIES/generic/include/boost/signals2/detail/signal_template.hpp @ 16:2665513ce2d3

Add boost headers

+/*
+  Template for Signa1, Signal2, ... classes that support signals
+  with 1, 2, ... parameters
+
+  Begin: 2007-01-23
+*/
+// Copyright Frank Mori Hess 2007-2008
+//
+// 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)
+
+// This file is included iteratively, and should not be protected from multiple inclusion
+
+#ifdef BOOST_NO_CXX11_VARIADIC_TEMPLATES
+#define BOOST_SIGNALS2_NUM_ARGS BOOST_PP_ITERATION()
+#else
+#define BOOST_SIGNALS2_NUM_ARGS 1
+#endif
+
+// R, T1, T2, ..., TN, Combiner, Group, GroupCompare, SlotFunction, ExtendedSlotFunction, Mutex
+#define BOOST_SIGNALS2_SIGNAL_TEMPLATE_INSTANTIATION \
+  BOOST_SIGNALS2_SIGNATURE_TEMPLATE_INSTANTIATION(BOOST_SIGNALS2_NUM_ARGS), \
+  Combiner, Group, GroupCompare, SlotFunction, ExtendedSlotFunction, Mutex
+
+namespace boost
+{
+  namespace signals2
+  {
+    namespace detail
+    {
+      // helper for bound_extended_slot_function that handles specialization for void return
+      template<typename R>
+        class BOOST_SIGNALS2_BOUND_EXTENDED_SLOT_FUNCTION_INVOKER_N(BOOST_SIGNALS2_NUM_ARGS)
+      {
+      public:
+        typedef R result_type;
+        template<typename ExtendedSlotFunction BOOST_SIGNALS2_PP_COMMA_IF(BOOST_SIGNALS2_NUM_ARGS)
+          BOOST_SIGNALS2_ARGS_TEMPLATE_DECL(BOOST_SIGNALS2_NUM_ARGS)>
+          result_type operator()(ExtendedSlotFunction &func, const connection &conn
+            BOOST_SIGNALS2_PP_COMMA_IF(BOOST_SIGNALS2_NUM_ARGS)
+            BOOST_SIGNALS2_FULL_REF_ARGS(BOOST_SIGNALS2_NUM_ARGS)) const
+        {
+          return func(conn BOOST_SIGNALS2_PP_COMMA_IF(BOOST_SIGNALS2_NUM_ARGS)
+            BOOST_SIGNALS2_SIGNATURE_ARG_NAMES(BOOST_SIGNALS2_NUM_ARGS));
+        }
+      };
+#ifdef BOOST_NO_VOID_RETURNS
+      template<>
+        class BOOST_SIGNALS2_BOUND_EXTENDED_SLOT_FUNCTION_INVOKER_N(BOOST_SIGNALS2_NUM_ARGS)<void>
+      {
+      public:
+        typedef result_type_wrapper<void>::type result_type;
+        template<typename ExtendedSlotFunction BOOST_SIGNALS2_PP_COMMA_IF(BOOST_SIGNALS2_NUM_ARGS)
+          BOOST_SIGNALS2_ARGS_TEMPLATE_DECL(BOOST_SIGNALS2_NUM_ARGS)>
+          result_type operator()(ExtendedSlotFunction &func, const connection &conn
+            BOOST_SIGNALS2_PP_COMMA_IF(BOOST_SIGNALS2_NUM_ARGS)
+            BOOST_SIGNALS2_FULL_REF_ARGS(BOOST_SIGNALS2_NUM_ARGS)) const
+        {
+          func(conn BOOST_SIGNALS2_PP_COMMA_IF(BOOST_SIGNALS2_NUM_ARGS)
+            BOOST_SIGNALS2_SIGNATURE_ARG_NAMES(BOOST_SIGNALS2_NUM_ARGS));
+          return result_type();
+        }
+      };
+#endif
+// wrapper around an signalN::extended_slot_function which binds the
+// connection argument so it looks like a normal
+// signalN::slot_function
+
+      template<typename ExtendedSlotFunction>
+        class BOOST_SIGNALS2_BOUND_EXTENDED_SLOT_FUNCTION_N(BOOST_SIGNALS2_NUM_ARGS)
+      {
+      public:
+        typedef typename result_type_wrapper<typename ExtendedSlotFunction::result_type>::type result_type;
+        BOOST_SIGNALS2_BOUND_EXTENDED_SLOT_FUNCTION_N(BOOST_SIGNALS2_NUM_ARGS)(const ExtendedSlotFunction &fun):
+          _fun(fun), _connection(new connection)
+        {}
+        void set_connection(const connection &conn)
+        {
+          *_connection = conn;
+        }
+
+#if BOOST_SIGNALS2_NUM_ARGS > 0
+        template<BOOST_SIGNALS2_ARGS_TEMPLATE_DECL(BOOST_SIGNALS2_NUM_ARGS)>
+#endif // BOOST_SIGNALS2_NUM_ARGS > 0
+          result_type operator()(BOOST_SIGNALS2_FULL_REF_ARGS(BOOST_SIGNALS2_NUM_ARGS))
+        {
+          return BOOST_SIGNALS2_BOUND_EXTENDED_SLOT_FUNCTION_INVOKER_N(BOOST_SIGNALS2_NUM_ARGS)
+            <typename ExtendedSlotFunction::result_type>()
+            (_fun, *_connection BOOST_SIGNALS2_PP_COMMA_IF(BOOST_SIGNALS2_NUM_ARGS)
+              BOOST_SIGNALS2_SIGNATURE_ARG_NAMES(BOOST_SIGNALS2_NUM_ARGS));
+        }
+        // const overload
+#if BOOST_SIGNALS2_NUM_ARGS > 0
+        template<BOOST_SIGNALS2_ARGS_TEMPLATE_DECL(BOOST_SIGNALS2_NUM_ARGS)>
+#endif // BOOST_SIGNALS2_NUM_ARGS > 0
+          result_type operator()(BOOST_SIGNALS2_FULL_REF_ARGS(BOOST_SIGNALS2_NUM_ARGS)) const
+        {
+          return BOOST_SIGNALS2_BOUND_EXTENDED_SLOT_FUNCTION_INVOKER_N(BOOST_SIGNALS2_NUM_ARGS)
+            <typename ExtendedSlotFunction::result_type>()
+            (_fun, *_connection BOOST_SIGNALS2_PP_COMMA_IF(BOOST_SIGNALS2_NUM_ARGS)
+              BOOST_SIGNALS2_SIGNATURE_ARG_NAMES(BOOST_SIGNALS2_NUM_ARGS));
+        }
+        template<typename T>
+          bool operator==(const T &other) const
+        {
+          return _fun == other;
+        }
+      private:
+        BOOST_SIGNALS2_BOUND_EXTENDED_SLOT_FUNCTION_N(BOOST_SIGNALS2_NUM_ARGS)()
+        {}
+
+        ExtendedSlotFunction _fun;
+        boost::shared_ptr<connection> _connection;
+      };
+
+      template<BOOST_SIGNALS2_SIGNAL_TEMPLATE_DECL(BOOST_SIGNALS2_NUM_ARGS)>
+        class BOOST_SIGNALS2_SIGNAL_IMPL_CLASS_NAME(BOOST_SIGNALS2_NUM_ARGS);
+
+      template<BOOST_SIGNALS2_SIGNAL_TEMPLATE_SPECIALIZATION_DECL(BOOST_SIGNALS2_NUM_ARGS)>
+      class BOOST_SIGNALS2_SIGNAL_IMPL_CLASS_NAME(BOOST_SIGNALS2_NUM_ARGS) BOOST_SIGNALS2_SIGNAL_TEMPLATE_SPECIALIZATION
+      {
+      public:
+        typedef SlotFunction slot_function_type;
+        // typedef slotN<Signature, SlotFunction> slot_type;
+        typedef BOOST_SIGNALS2_SLOT_CLASS_NAME(BOOST_SIGNALS2_NUM_ARGS)
+          <BOOST_SIGNALS2_SIGNATURE_TEMPLATE_INSTANTIATION(BOOST_SIGNALS2_NUM_ARGS),
+          slot_function_type> slot_type;
+        typedef ExtendedSlotFunction extended_slot_function_type;
+        // typedef slotN+1<R, const connection &, T1, T2, ..., TN, extended_slot_function_type> extended_slot_type;
+        typedef BOOST_SIGNALS2_EXTENDED_SLOT_TYPE(BOOST_SIGNALS2_NUM_ARGS) extended_slot_type;
+        typedef typename nonvoid<typename slot_function_type::result_type>::type nonvoid_slot_result_type;
+      private:
+#ifdef BOOST_NO_CXX11_VARIADIC_TEMPLATES
+        class slot_invoker;
+#else // BOOST_NO_CXX11_VARIADIC_TEMPLATES
+        typedef variadic_slot_invoker<nonvoid_slot_result_type, Args...> slot_invoker;
+#endif // BOOST_NO_CXX11_VARIADIC_TEMPLATES
+        typedef slot_call_iterator_cache<nonvoid_slot_result_type, slot_invoker> slot_call_iterator_cache_type;
+        typedef typename group_key<Group>::type group_key_type;
+        typedef shared_ptr<connection_body<group_key_type, slot_type, Mutex> > connection_body_type;
+        typedef grouped_list<Group, GroupCompare, connection_body_type> connection_list_type;
+        typedef BOOST_SIGNALS2_BOUND_EXTENDED_SLOT_FUNCTION_N(BOOST_SIGNALS2_NUM_ARGS)<extended_slot_function_type>
+          bound_extended_slot_function_type;
+      public:
+        typedef Combiner combiner_type;
+        typedef typename result_type_wrapper<typename combiner_type::result_type>::type result_type;
+        typedef Group group_type;
+        typedef GroupCompare group_compare_type;
+        typedef typename detail::slot_call_iterator_t<slot_invoker,
+          typename connection_list_type::iterator, connection_body<group_key_type, slot_type, Mutex> > slot_call_iterator;
+
+        BOOST_SIGNALS2_SIGNAL_IMPL_CLASS_NAME(BOOST_SIGNALS2_NUM_ARGS)(const combiner_type &combiner_arg,
+          const group_compare_type &group_compare):
+          _shared_state(new invocation_state(connection_list_type(group_compare), combiner_arg)),
+          _garbage_collector_it(_shared_state->connection_bodies().end())
+        {}
+        // connect slot
+        connection connect(const slot_type &slot, connect_position position = at_back)
+        {
+          unique_lock<mutex_type> lock(_mutex);
+          return nolock_connect(slot, position);
+        }
+        connection connect(const group_type &group,
+          const slot_type &slot, connect_position position = at_back)
+        {
+          unique_lock<Mutex> lock(_mutex);
+          return nolock_connect(group, slot, position);
+        }
+        // connect extended slot
+        connection connect_extended(const extended_slot_type &ext_slot, connect_position position = at_back)
+        {
+          unique_lock<mutex_type> lock(_mutex);
+          bound_extended_slot_function_type bound_slot(ext_slot.slot_function());
+          slot_type slot = replace_slot_function<slot_type>(ext_slot, bound_slot);
+          connection conn = nolock_connect(slot, position);
+          bound_slot.set_connection(conn);
+          return conn;
+        }
+        connection connect_extended(const group_type &group,
+          const extended_slot_type &ext_slot, connect_position position = at_back)
+        {
+          unique_lock<Mutex> lock(_mutex);
+          bound_extended_slot_function_type bound_slot(ext_slot.slot_function());
+          slot_type slot = replace_slot_function<slot_type>(ext_slot, bound_slot);
+          connection conn = nolock_connect(group, slot, position);
+          bound_slot.set_connection(conn);
+          return conn;
+        }
+        // disconnect slot(s)
+        void disconnect_all_slots()
+        {
+          shared_ptr<invocation_state> local_state =
+            get_readable_state();
+          typename connection_list_type::iterator it;
+          for(it = local_state->connection_bodies().begin();
+            it != local_state->connection_bodies().end(); ++it)
+          {
+            (*it)->disconnect();
+          }
+        }
+        void disconnect(const group_type &group)
+        {
+          shared_ptr<invocation_state> local_state =
+            get_readable_state();
+          group_key_type group_key(grouped_slots, group);
+          typename connection_list_type::iterator it;
+          typename connection_list_type::iterator end_it =
+            local_state->connection_bodies().upper_bound(group_key);
+          for(it = local_state->connection_bodies().lower_bound(group_key);
+            it != end_it; ++it)
+          {
+            (*it)->disconnect();
+          }
+        }
+        template <typename T>
+        void disconnect(const T &slot)
+        {
+          typedef mpl::bool_<(is_convertible<T, group_type>::value)> is_group;
+          do_disconnect(slot, is_group());
+        }
+        // emit signal
+        result_type operator ()(BOOST_SIGNALS2_SIGNATURE_FULL_ARGS(BOOST_SIGNALS2_NUM_ARGS))
+        {
+          shared_ptr<invocation_state> local_state;
+          typename connection_list_type::iterator it;
+          {
+            unique_lock<mutex_type> list_lock(_mutex);
+            // only clean up if it is safe to do so
+            if(_shared_state.unique())
+              nolock_cleanup_connections(false, 1);
+            /* Make a local copy of _shared_state while holding mutex, so we are
+            thread safe against the combiner or connection list getting modified
+            during invocation. */
+            local_state = _shared_state;
+          }
+          slot_invoker invoker = slot_invoker(BOOST_SIGNALS2_SIGNATURE_ARG_NAMES(BOOST_SIGNALS2_NUM_ARGS));
+          slot_call_iterator_cache_type cache(invoker);
+          invocation_janitor janitor(cache, *this, &local_state->connection_bodies());
+          return detail::combiner_invoker<typename combiner_type::result_type>()
+            (
+              local_state->combiner(),
+              slot_call_iterator(local_state->connection_bodies().begin(), local_state->connection_bodies().end(), cache),
+              slot_call_iterator(local_state->connection_bodies().end(), local_state->connection_bodies().end(), cache)
+            );
+        }
+        result_type operator ()(BOOST_SIGNALS2_SIGNATURE_FULL_ARGS(BOOST_SIGNALS2_NUM_ARGS)) const
+        {
+          shared_ptr<invocation_state> local_state;
+          typename connection_list_type::iterator it;
+          {
+            unique_lock<mutex_type> list_lock(_mutex);
+            // only clean up if it is safe to do so
+            if(_shared_state.unique())
+              nolock_cleanup_connections(false, 1);
+            /* Make a local copy of _shared_state while holding mutex, so we are
+            thread safe against the combiner or connection list getting modified
+            during invocation. */
+            local_state = _shared_state;
+          }
+          slot_invoker invoker = slot_invoker(BOOST_SIGNALS2_SIGNATURE_ARG_NAMES(BOOST_SIGNALS2_NUM_ARGS));
+          slot_call_iterator_cache_type cache(invoker);
+          invocation_janitor janitor(cache, *this, &local_state->connection_bodies());
+          return detail::combiner_invoker<typename combiner_type::result_type>()
+            (
+              local_state->combiner(),
+              slot_call_iterator(local_state->connection_bodies().begin(), local_state->connection_bodies().end(), cache),
+              slot_call_iterator(local_state->connection_bodies().end(), local_state->connection_bodies().end(), cache)
+            );
+        }
+        std::size_t num_slots() const
+        {
+          shared_ptr<invocation_state> local_state =
+            get_readable_state();
+          typename connection_list_type::iterator it;
+          std::size_t count = 0;
+          for(it = local_state->connection_bodies().begin();
+            it != local_state->connection_bodies().end(); ++it)
+          {
+            if((*it)->connected()) ++count;
+          }
+          return count;
+        }
+        bool empty() const
+        {
+          shared_ptr<invocation_state> local_state =
+            get_readable_state();
+          typename connection_list_type::iterator it;
+          for(it = local_state->connection_bodies().begin();
+            it != local_state->connection_bodies().end(); ++it)
+          {
+            if((*it)->connected()) return false;
+          }
+          return true;
+        }
+        combiner_type combiner() const
+        {
+          unique_lock<mutex_type> lock(_mutex);
+          return _shared_state->combiner();
+        }
+        void set_combiner(const combiner_type &combiner_arg)
+        {
+          unique_lock<mutex_type> lock(_mutex);
+          if(_shared_state.unique())
+            _shared_state->combiner() = combiner_arg;
+          else
+            _shared_state.reset(new invocation_state(*_shared_state, combiner_arg));
+        }
+      private:
+        typedef Mutex mutex_type;
+
+        // slot_invoker is passed to slot_call_iterator_t to run slots
+#ifdef BOOST_NO_CXX11_VARIADIC_TEMPLATES
+        class slot_invoker
+        {
+        public:
+          typedef nonvoid_slot_result_type result_type;
+// typename add_reference<Tn>::type
+#define BOOST_SIGNALS2_ADD_REF_TYPE(z, n, data) \
+  typename add_reference<BOOST_PP_CAT(T, BOOST_PP_INC(n))>::type
+// typename add_reference<Tn>::type argn
+#define BOOST_SIGNALS2_ADD_REF_ARG(z, n, data) \
+  BOOST_SIGNALS2_ADD_REF_TYPE(~, n, ~) \
+  BOOST_SIGNALS2_SIGNATURE_ARG_NAME(~, n, ~)
+// typename add_reference<T1>::type arg1, typename add_reference<T2>::type arg2, ..., typename add_reference<Tn>::type argn
+#define BOOST_SIGNALS2_ADD_REF_ARGS(arity) \
+  BOOST_PP_ENUM(arity, BOOST_SIGNALS2_ADD_REF_ARG, ~)
+          slot_invoker(BOOST_SIGNALS2_ADD_REF_ARGS(BOOST_SIGNALS2_NUM_ARGS)) BOOST_PP_EXPR_IF(BOOST_SIGNALS2_NUM_ARGS, :)
+#undef BOOST_SIGNALS2_ADD_REF_ARGS
+
+// m_argn
+#define BOOST_SIGNALS2_M_ARG_NAME(z, n, data) BOOST_PP_CAT(m_arg, BOOST_PP_INC(n))
+// m_argn ( argn )
+#define BOOST_SIGNALS2_MISC_STATEMENT(z, n, data) \
+  BOOST_SIGNALS2_M_ARG_NAME(~, n, ~) ( BOOST_SIGNALS2_SIGNATURE_ARG_NAME(~, n, ~) )
+// m_arg1(arg1), m_arg2(arg2), ..., m_argn(argn)
+            BOOST_PP_ENUM(BOOST_SIGNALS2_NUM_ARGS, BOOST_SIGNALS2_MISC_STATEMENT, ~)
+#undef BOOST_SIGNALS2_MISC_STATEMENT
+          {}
+          result_type operator ()(const connection_body_type &connectionBody) const
+          {
+            result_type *resolver = 0;
+            return m_invoke(connectionBody,
+              resolver);
+          }
+        private:
+          // declare assignment operator private since this class might have reference or const members
+          slot_invoker & operator=(const slot_invoker &);
+
+#define BOOST_SIGNALS2_ADD_REF_M_ARG_STATEMENT(z, n, data) \
+  BOOST_SIGNALS2_ADD_REF_TYPE(~, n, ~) BOOST_SIGNALS2_M_ARG_NAME(~, n, ~) ;
+          BOOST_PP_REPEAT(BOOST_SIGNALS2_NUM_ARGS, BOOST_SIGNALS2_ADD_REF_M_ARG_STATEMENT, ~)
+#undef BOOST_SIGNALS2_ADD_REF_M_ARG_STATEMENT
+#undef BOOST_SIGNALS2_ADD_REF_ARG
+#undef BOOST_SIGNALS2_ADD_REF_TYPE
+
+// m_arg1, m_arg2, ..., m_argn
+#define BOOST_SIGNALS2_M_ARG_NAMES(arity) BOOST_PP_ENUM(arity, BOOST_SIGNALS2_M_ARG_NAME, ~)
+          result_type m_invoke(const connection_body_type &connectionBody,
+            const void_type *) const
+          {
+            connectionBody->slot.slot_function()(BOOST_SIGNALS2_M_ARG_NAMES(BOOST_SIGNALS2_NUM_ARGS));
+            return void_type();
+          }
+          result_type m_invoke(const connection_body_type &connectionBody, ...) const
+          {
+            return connectionBody->slot.slot_function()(BOOST_SIGNALS2_M_ARG_NAMES(BOOST_SIGNALS2_NUM_ARGS));
+          }
+        };
+#undef BOOST_SIGNALS2_M_ARG_NAMES
+#undef BOOST_SIGNALS2_M_ARG_NAME
+
+#endif // BOOST_NO_CXX11_VARIADIC_TEMPLATES
+        // a struct used to optimize (minimize) the number of shared_ptrs that need to be created
+        // inside operator()
+        class invocation_state
+        {
+        public:
+          invocation_state(const connection_list_type &connections_in,
+            const combiner_type &combiner_in): _connection_bodies(new connection_list_type(connections_in)),
+            _combiner(new combiner_type(combiner_in))
+          {}
+          invocation_state(const invocation_state &other, const connection_list_type &connections_in):
+            _connection_bodies(new connection_list_type(connections_in)),
+            _combiner(other._combiner)
+          {}
+          invocation_state(const invocation_state &other, const combiner_type &combiner_in):
+            _connection_bodies(other._connection_bodies),
+            _combiner(new combiner_type(combiner_in))
+          {}
+          connection_list_type & connection_bodies() { return *_connection_bodies; }
+          const connection_list_type & connection_bodies() const { return *_connection_bodies; }
+          combiner_type & combiner() { return *_combiner; }
+          const combiner_type & combiner() const { return *_combiner; }
+        private:
+          invocation_state(const invocation_state &);
+
+          shared_ptr<connection_list_type> _connection_bodies;
+          shared_ptr<combiner_type> _combiner;
+        };
+        // Destructor of invocation_janitor does some cleanup when a signal invocation completes.
+        // Code can't be put directly in signal's operator() due to complications from void return types.
+        class invocation_janitor
+        {
+        public:
+          typedef BOOST_SIGNALS2_SIGNAL_IMPL_CLASS_NAME(BOOST_SIGNALS2_NUM_ARGS) signal_type;
+          invocation_janitor
+          (
+            const slot_call_iterator_cache_type &cache,
+            const signal_type &sig,
+            const connection_list_type *connection_bodies
+          ):_cache(cache), _sig(sig), _connection_bodies(connection_bodies)
+          {}
+          ~invocation_janitor()
+          {
+            // force a full cleanup of disconnected slots if there are too many
+            if(_cache.disconnected_slot_count > _cache.connected_slot_count)
+            {
+              _sig.force_cleanup_connections(_connection_bodies);
+            }
+          }
+        private:
+          const slot_call_iterator_cache_type &_cache;
+          const signal_type &_sig;
+          const connection_list_type *_connection_bodies;
+        };
+
+        // clean up disconnected connections
+        void nolock_cleanup_connections_from(bool grab_tracked,
+          const typename connection_list_type::iterator &begin, unsigned count = 0) const
+        {
+          BOOST_ASSERT(_shared_state.unique());
+          typename connection_list_type::iterator it;
+          unsigned i;
+          for(it = begin, i = 0;
+            it != _shared_state->connection_bodies().end() && (count == 0 || i < count);
+            ++i)
+          {
+            bool connected;
+            {
+              unique_lock<connection_body_base> lock(**it);
+              if(grab_tracked)
+                (*it)->nolock_slot_expired();
+              connected = (*it)->nolock_nograb_connected();
+            }// scoped lock destructs here, safe to erase now
+            if(connected == false)
+            {
+              it = _shared_state->connection_bodies().erase((*it)->group_key(), it);
+            }else
+            {
+              ++it;
+            }
+          }
+          _garbage_collector_it = it;
+        }
+        // clean up a few connections in constant time
+        void nolock_cleanup_connections(bool grab_tracked, unsigned count) const
+        {
+          BOOST_ASSERT(_shared_state.unique());
+          typename connection_list_type::iterator begin;
+          if(_garbage_collector_it == _shared_state->connection_bodies().end())
+          {
+            begin = _shared_state->connection_bodies().begin();
+          }else
+          {
+            begin = _garbage_collector_it;
+          }
+          nolock_cleanup_connections_from(grab_tracked, begin, count);
+        }
+        /* Make a new copy of the slot list if it is currently being read somewhere else
+        */
+        void nolock_force_unique_connection_list()
+        {
+          if(_shared_state.unique() == false)
+          {
+            _shared_state.reset(new invocation_state(*_shared_state, _shared_state->connection_bodies()));
+            nolock_cleanup_connections_from(true, _shared_state->connection_bodies().begin());
+          }else
+          {
+            /* We need to try and check more than just 1 connection here to avoid corner
+            cases where certain repeated connect/disconnect patterns cause the slot
+            list to grow without limit. */
+            nolock_cleanup_connections(true, 2);
+          }
+        }
+        // force a full cleanup of the connection list
+        void force_cleanup_connections(const connection_list_type *connection_bodies) const
+        {
+          unique_lock<mutex_type> list_lock(_mutex);
+          // if the connection list passed in as a parameter is no longer in use,
+          // we don't need to do any cleanup.
+          if(&_shared_state->connection_bodies() != connection_bodies)
+          {
+            return;
+          }
+          if(_shared_state.unique() == false)
+          {
+            _shared_state.reset(new invocation_state(*_shared_state, _shared_state->connection_bodies()));
+          }
+          nolock_cleanup_connections_from(false, _shared_state->connection_bodies().begin());
+        }
+        shared_ptr<invocation_state> get_readable_state() const
+        {
+          unique_lock<mutex_type> list_lock(_mutex);
+          return _shared_state;
+        }
+        connection_body_type create_new_connection(const slot_type &slot)
+        {
+          nolock_force_unique_connection_list();
+          return connection_body_type(new connection_body<group_key_type, slot_type, Mutex>(slot));
+        }
+        void do_disconnect(const group_type &group, mpl::bool_<true> /* is_group */)
+        {
+          disconnect(group);
+        }
+        template<typename T>
+        void do_disconnect(const T &slot, mpl::bool_<false> /* is_group */)
+        {
+          shared_ptr<invocation_state> local_state =
+            get_readable_state();
+          typename connection_list_type::iterator it;
+          for(it = local_state->connection_bodies().begin();
+            it != local_state->connection_bodies().end(); ++it)
+          {
+            unique_lock<connection_body_base> lock(**it);
+            if((*it)->slot.slot_function() == slot)
+            {
+              (*it)->nolock_disconnect();
+            }else
+            {
+              // check for wrapped extended slot
+              bound_extended_slot_function_type *fp;
+              fp = (*it)->slot.slot_function().template target<bound_extended_slot_function_type>();
+              if(fp && *fp == slot)
+              {
+                (*it)->nolock_disconnect();
+              }
+            }
+          }
+        }
+        // connect slot
+        connection nolock_connect(const slot_type &slot, connect_position position)
+        {
+          connection_body_type newConnectionBody =
+            create_new_connection(slot);
+          group_key_type group_key;
+          if(position == at_back)
+          {
+            group_key.first = back_ungrouped_slots;
+            _shared_state->connection_bodies().push_back(group_key, newConnectionBody);
+          }else
+          {
+            group_key.first = front_ungrouped_slots;
+            _shared_state->connection_bodies().push_front(group_key, newConnectionBody);
+          }
+          newConnectionBody->set_group_key(group_key);
+          return connection(newConnectionBody);
+        }
+        connection nolock_connect(const group_type &group,
+          const slot_type &slot, connect_position position)
+        {
+          connection_body_type newConnectionBody =
+            create_new_connection(slot);
+          // update map to first connection body in group if needed
+          group_key_type group_key(grouped_slots, group);
+          newConnectionBody->set_group_key(group_key);
+          if(position == at_back)
+          {
+            _shared_state->connection_bodies().push_back(group_key, newConnectionBody);
+          }else  // at_front
+          {
+            _shared_state->connection_bodies().push_front(group_key, newConnectionBody);
+          }
+          return connection(newConnectionBody);
+        }
+
+        // _shared_state is mutable so we can do force_cleanup_connections during a const invocation
+        mutable shared_ptr<invocation_state> _shared_state;
+        mutable typename connection_list_type::iterator _garbage_collector_it;
+        // connection list mutex must never be locked when attempting a blocking lock on a slot,
+        // or you could deadlock.
+        mutable mutex_type _mutex;
+      };
+
+      template<BOOST_SIGNALS2_SIGNAL_TEMPLATE_DECL(BOOST_SIGNALS2_NUM_ARGS)>
+        class BOOST_SIGNALS2_WEAK_SIGNAL_CLASS_NAME(BOOST_SIGNALS2_NUM_ARGS);
+    }
+
+    template<BOOST_SIGNALS2_SIGNAL_TEMPLATE_DEFAULTED_DECL(BOOST_SIGNALS2_NUM_ARGS)>
+      class BOOST_SIGNALS2_SIGNAL_CLASS_NAME(BOOST_SIGNALS2_NUM_ARGS);
+
+    template<BOOST_SIGNALS2_SIGNAL_TEMPLATE_SPECIALIZATION_DECL(BOOST_SIGNALS2_NUM_ARGS)>
+    class BOOST_SIGNALS2_SIGNAL_CLASS_NAME(BOOST_SIGNALS2_NUM_ARGS)
+      BOOST_SIGNALS2_SIGNAL_TEMPLATE_SPECIALIZATION: public signal_base,
+      public detail::BOOST_SIGNALS2_STD_FUNCTIONAL_BASE
+        (typename detail::result_type_wrapper<typename Combiner::result_type>::type)
+    {
+      typedef detail::BOOST_SIGNALS2_SIGNAL_IMPL_CLASS_NAME(BOOST_SIGNALS2_NUM_ARGS)
+        <BOOST_SIGNALS2_SIGNAL_TEMPLATE_INSTANTIATION> impl_class;
+    public:
+      typedef detail::BOOST_SIGNALS2_WEAK_SIGNAL_CLASS_NAME(BOOST_SIGNALS2_NUM_ARGS)
+        <BOOST_SIGNALS2_SIGNAL_TEMPLATE_INSTANTIATION> weak_signal_type;
+      friend class detail::BOOST_SIGNALS2_WEAK_SIGNAL_CLASS_NAME(BOOST_SIGNALS2_NUM_ARGS)
+        <BOOST_SIGNALS2_SIGNAL_TEMPLATE_INSTANTIATION>;
+
+      typedef SlotFunction slot_function_type;
+      // typedef slotN<Signature, SlotFunction> slot_type;
+      typedef typename impl_class::slot_type slot_type;
+      typedef typename impl_class::extended_slot_function_type extended_slot_function_type;
+      typedef typename impl_class::extended_slot_type extended_slot_type;
+      typedef typename slot_function_type::result_type slot_result_type;
+      typedef Combiner combiner_type;
+      typedef typename impl_class::result_type result_type;
+      typedef Group group_type;
+      typedef GroupCompare group_compare_type;
+      typedef typename impl_class::slot_call_iterator
+        slot_call_iterator;
+      typedef typename mpl::identity<BOOST_SIGNALS2_SIGNATURE_FUNCTION_TYPE(BOOST_SIGNALS2_NUM_ARGS)>::type signature_type;
+
+#ifdef BOOST_NO_CXX11_VARIADIC_TEMPLATES
+
+// typedef Tn argn_type;
+#define BOOST_SIGNALS2_MISC_STATEMENT(z, n, data) \
+  typedef BOOST_PP_CAT(T, BOOST_PP_INC(n)) BOOST_PP_CAT(BOOST_PP_CAT(arg, BOOST_PP_INC(n)), _type);
+      BOOST_PP_REPEAT(BOOST_SIGNALS2_NUM_ARGS, BOOST_SIGNALS2_MISC_STATEMENT, ~)
+#undef BOOST_SIGNALS2_MISC_STATEMENT
+#if BOOST_SIGNALS2_NUM_ARGS == 1
+      typedef arg1_type argument_type;
+#elif BOOST_SIGNALS2_NUM_ARGS == 2
+      typedef arg1_type first_argument_type;
+      typedef arg2_type second_argument_type;
+#endif
+
+      template<unsigned n> class arg : public
+        detail::BOOST_SIGNALS2_PREPROCESSED_ARG_N_TYPE_CLASS_NAME(BOOST_SIGNALS2_NUM_ARGS)
+        <n BOOST_SIGNALS2_PP_COMMA_IF(BOOST_SIGNALS2_NUM_ARGS)
+        BOOST_SIGNALS2_ARGS_TEMPLATE_INSTANTIATION(BOOST_SIGNALS2_NUM_ARGS)>
+      {};
+
+      BOOST_STATIC_CONSTANT(int, arity = BOOST_SIGNALS2_NUM_ARGS);
+
+#else // BOOST_NO_CXX11_VARIADIC_TEMPLATES
+
+      template<unsigned n> class arg
+      {
+      public:
+        typedef typename detail::variadic_arg_type<n, Args...>::type type;
+      };
+      BOOST_STATIC_CONSTANT(int, arity = sizeof...(Args));
+
+#endif // BOOST_NO_CXX11_VARIADIC_TEMPLATES
+
+      BOOST_SIGNALS2_SIGNAL_CLASS_NAME(BOOST_SIGNALS2_NUM_ARGS)(const combiner_type &combiner_arg = combiner_type(),
+        const group_compare_type &group_compare = group_compare_type()):
+        _pimpl(new impl_class(combiner_arg, group_compare))
+      {};
+      virtual ~BOOST_SIGNALS2_SIGNAL_CLASS_NAME(BOOST_SIGNALS2_NUM_ARGS)()
+      {
+        disconnect_all_slots();
+      }
+      connection connect(const slot_type &slot, connect_position position = at_back)
+      {
+        return (*_pimpl).connect(slot, position);
+      }
+      connection connect(const group_type &group,
+        const slot_type &slot, connect_position position = at_back)
+      {
+        return (*_pimpl).connect(group, slot, position);
+      }
+      connection connect_extended(const extended_slot_type &slot, connect_position position = at_back)
+      {
+        return (*_pimpl).connect_extended(slot, position);
+      }
+      connection connect_extended(const group_type &group,
+        const extended_slot_type &slot, connect_position position = at_back)
+      {
+        return (*_pimpl).connect_extended(group, slot, position);
+      }
+      void disconnect_all_slots()
+      {
+        (*_pimpl).disconnect_all_slots();
+      }
+      void disconnect(const group_type &group)
+      {
+        (*_pimpl).disconnect(group);
+      }
+      template <typename T>
+      void disconnect(const T &slot)
+      {
+        (*_pimpl).disconnect(slot);
+      }
+      result_type operator ()(BOOST_SIGNALS2_SIGNATURE_FULL_ARGS(BOOST_SIGNALS2_NUM_ARGS))
+      {
+        return (*_pimpl)(BOOST_SIGNALS2_SIGNATURE_ARG_NAMES(BOOST_SIGNALS2_NUM_ARGS));
+      }
+      result_type operator ()(BOOST_SIGNALS2_SIGNATURE_FULL_ARGS(BOOST_SIGNALS2_NUM_ARGS)) const
+      {
+        return (*_pimpl)(BOOST_SIGNALS2_SIGNATURE_ARG_NAMES(BOOST_SIGNALS2_NUM_ARGS));
+      }
+      std::size_t num_slots() const
+      {
+        return (*_pimpl).num_slots();
+      }
+      bool empty() const
+      {
+        return (*_pimpl).empty();
+      }
+      combiner_type combiner() const
+      {
+        return (*_pimpl).combiner();
+      }
+      void set_combiner(const combiner_type &combiner_arg)
+      {
+        return (*_pimpl).set_combiner(combiner_arg);
+      }
+      void swap(BOOST_SIGNALS2_SIGNAL_CLASS_NAME(BOOST_SIGNALS2_NUM_ARGS) & other)
+      {
+        using std::swap;
+        swap(_pimpl, other._pimpl);
+      }
+    protected:
+      virtual shared_ptr<void> lock_pimpl() const
+      {
+        return _pimpl;
+      }
+    private:
+      shared_ptr<impl_class>
+        _pimpl;
+    };
+
+#ifdef BOOST_NO_CXX11_VARIADIC_TEMPLATES
+    // free swap function for signalN classes, findable by ADL
+    template<BOOST_SIGNALS2_SIGNAL_TEMPLATE_DECL(BOOST_SIGNALS2_NUM_ARGS)>
+      void swap(
+        BOOST_SIGNALS2_SIGNAL_CLASS_NAME(BOOST_SIGNALS2_NUM_ARGS) <BOOST_SIGNALS2_SIGNAL_TEMPLATE_INSTANTIATION> &sig1,
+        BOOST_SIGNALS2_SIGNAL_CLASS_NAME(BOOST_SIGNALS2_NUM_ARGS) <BOOST_SIGNALS2_SIGNAL_TEMPLATE_INSTANTIATION> &sig2 )
+    {
+      sig1.swap(sig2);
+    }
+#endif
+
+    namespace detail
+    {
+      // wrapper class for storing other signals as slots with automatic lifetime tracking
+      template<BOOST_SIGNALS2_SIGNAL_TEMPLATE_DECL(BOOST_SIGNALS2_NUM_ARGS)>
+        class BOOST_SIGNALS2_WEAK_SIGNAL_CLASS_NAME(BOOST_SIGNALS2_NUM_ARGS);
+
+      template<BOOST_SIGNALS2_SIGNAL_TEMPLATE_SPECIALIZATION_DECL(BOOST_SIGNALS2_NUM_ARGS)>
+        class BOOST_SIGNALS2_WEAK_SIGNAL_CLASS_NAME(BOOST_SIGNALS2_NUM_ARGS)
+        BOOST_SIGNALS2_SIGNAL_TEMPLATE_SPECIALIZATION
+      {
+      public:
+        typedef typename BOOST_SIGNALS2_SIGNAL_CLASS_NAME(BOOST_SIGNALS2_NUM_ARGS)
+          <BOOST_SIGNALS2_SIGNAL_TEMPLATE_INSTANTIATION>::result_type
+          result_type;
+
+        BOOST_SIGNALS2_WEAK_SIGNAL_CLASS_NAME(BOOST_SIGNALS2_NUM_ARGS)
+          (const BOOST_SIGNALS2_SIGNAL_CLASS_NAME(BOOST_SIGNALS2_NUM_ARGS)
+          <BOOST_SIGNALS2_SIGNAL_TEMPLATE_INSTANTIATION>
+          &signal):
+          _weak_pimpl(signal._pimpl)
+        {}
+        result_type operator ()(BOOST_SIGNALS2_SIGNATURE_FULL_ARGS(BOOST_SIGNALS2_NUM_ARGS))
+        {
+          shared_ptr<detail::BOOST_SIGNALS2_SIGNAL_IMPL_CLASS_NAME(BOOST_SIGNALS2_NUM_ARGS)
+            <BOOST_SIGNALS2_SIGNAL_TEMPLATE_INSTANTIATION> >
+            shared_pimpl(_weak_pimpl.lock());
+          if(shared_pimpl == 0) boost::throw_exception(expired_slot());
+          return (*shared_pimpl)(BOOST_SIGNALS2_SIGNATURE_ARG_NAMES(BOOST_SIGNALS2_NUM_ARGS));
+        }
+        result_type operator ()(BOOST_SIGNALS2_SIGNATURE_FULL_ARGS(BOOST_SIGNALS2_NUM_ARGS)) const
+        {
+          shared_ptr<detail::BOOST_SIGNALS2_SIGNAL_IMPL_CLASS_NAME(BOOST_SIGNALS2_NUM_ARGS)
+            <BOOST_SIGNALS2_SIGNAL_TEMPLATE_INSTANTIATION> >
+            shared_pimpl(_weak_pimpl.lock());
+          if(shared_pimpl == 0) boost::throw_exception(expired_slot());
+          return (*shared_pimpl)(BOOST_SIGNALS2_SIGNATURE_ARG_NAMES(BOOST_SIGNALS2_NUM_ARGS));
+        }
+      private:
+        boost::weak_ptr<detail::BOOST_SIGNALS2_SIGNAL_IMPL_CLASS_NAME(BOOST_SIGNALS2_NUM_ARGS)
+          <BOOST_SIGNALS2_SIGNAL_TEMPLATE_INSTANTIATION> > _weak_pimpl;
+      };
+
+#ifndef BOOST_NO_CXX11_VARIADIC_TEMPLATES
+      template<int arity, typename Signature>
+        class extended_signature: public variadic_extended_signature<Signature>
+      {};
+#else // BOOST_NO_CXX11_VARIADIC_TEMPLATES
+      template<int arity, typename Signature>
+        class extended_signature;
+      // partial template specialization
+      template<typename Signature>
+        class extended_signature<BOOST_SIGNALS2_NUM_ARGS, Signature>
+      {
+      public:
+// typename function_traits<Signature>::result_type (
+// const boost::signals2::connection &,
+// typename function_traits<Signature>::arg1_type,
+// typename function_traits<Signature>::arg2_type,
+// ...,
+// typename function_traits<Signature>::argn_type)
+#define BOOST_SIGNALS2_EXT_SIGNATURE(arity, Signature) \
+  typename function_traits<Signature>::result_type ( \
+  const boost::signals2::connection & BOOST_SIGNALS2_PP_COMMA_IF(BOOST_SIGNALS2_NUM_ARGS) \
+  BOOST_PP_ENUM(arity, BOOST_SIGNALS2_SIGNATURE_TO_ARGN_TYPE, Signature) )
+        typedef function<BOOST_SIGNALS2_EXT_SIGNATURE(BOOST_SIGNALS2_NUM_ARGS, Signature)> function_type;
+#undef BOOST_SIGNALS2_EXT_SIGNATURE
+      };
+
+      template<unsigned arity, typename Signature, typename Combiner,
+        typename Group, typename GroupCompare, typename SlotFunction,
+        typename ExtendedSlotFunction, typename Mutex>
+      class signalN;
+      // partial template specialization
+      template<typename Signature, typename Combiner, typename Group,
+        typename GroupCompare, typename SlotFunction,
+        typename ExtendedSlotFunction, typename Mutex>
+      class signalN<BOOST_SIGNALS2_NUM_ARGS, Signature, Combiner, Group,
+        GroupCompare, SlotFunction, ExtendedSlotFunction, Mutex>
+      {
+      public:
+        typedef BOOST_SIGNALS2_SIGNAL_CLASS_NAME(BOOST_SIGNALS2_NUM_ARGS)<
+          BOOST_SIGNALS2_PORTABLE_SIGNATURE(BOOST_SIGNALS2_NUM_ARGS, Signature),
+          Combiner, Group,
+          GroupCompare, SlotFunction, ExtendedSlotFunction, Mutex> type;
+      };
+
+#endif // BOOST_NO_CXX11_VARIADIC_TEMPLATES
+
+    } // namespace detail
+  } // namespace signals2
+} // namespace boost
+
+#undef BOOST_SIGNALS2_NUM_ARGS
+#undef BOOST_SIGNALS2_SIGNAL_TEMPLATE_INSTANTIATION