Chris@16: /*
Chris@16:   boost::signals2::connection provides a handle to a signal/slot connection.
Chris@16: 
Chris@16:   Author: Frank Mori Hess <fmhess@users.sourceforge.net>
Chris@16:   Begin: 2007-01-23
Chris@16: */
Chris@16: // Copyright Frank Mori Hess 2007-2008.
Chris@16: // Distributed under the Boost Software License, Version
Chris@16: // 1.0. (See accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: // See http://www.boost.org/libs/signals2 for library home page.
Chris@16: 
Chris@16: #ifndef BOOST_SIGNALS2_CONNECTION_HPP
Chris@16: #define BOOST_SIGNALS2_CONNECTION_HPP
Chris@16: 
Chris@16: #include <boost/function.hpp>
Chris@16: #include <boost/mpl/bool.hpp>
Chris@16: #include <boost/noncopyable.hpp>
Chris@16: #include <boost/shared_ptr.hpp>
Chris@16: #include <boost/signals2/detail/null_output_iterator.hpp>
Chris@16: #include <boost/signals2/detail/unique_lock.hpp>
Chris@16: #include <boost/signals2/slot.hpp>
Chris@16: #include <boost/weak_ptr.hpp>
Chris@16: 
Chris@16: namespace boost
Chris@16: {
Chris@16:   namespace signals2
Chris@16:   {
Chris@16:     extern inline void null_deleter(const void*) {}
Chris@16:     namespace detail
Chris@16:     {
Chris@16:       class connection_body_base
Chris@16:       {
Chris@16:       public:
Chris@16:         connection_body_base():
Chris@16:           _connected(true)
Chris@16:         {
Chris@16:         }
Chris@16:         virtual ~connection_body_base() {}
Chris@16:         void disconnect()
Chris@16:         {
Chris@16:           unique_lock<connection_body_base> local_lock(*this);
Chris@16:           nolock_disconnect();
Chris@16:         }
Chris@16:         void nolock_disconnect()
Chris@16:         {
Chris@16:           _connected = false;
Chris@16:         }
Chris@16:         virtual bool connected() const = 0;
Chris@16:         shared_ptr<void> get_blocker()
Chris@16:         {
Chris@16:           unique_lock<connection_body_base> local_lock(*this);
Chris@16:           shared_ptr<void> blocker = _weak_blocker.lock();
Chris@16:           if(blocker == shared_ptr<void>())
Chris@16:           {
Chris@16:             blocker.reset(this, &null_deleter);
Chris@16:             _weak_blocker = blocker;
Chris@16:           }
Chris@16:           return blocker;
Chris@16:         }
Chris@16:         bool blocked() const
Chris@16:         {
Chris@16:           return !_weak_blocker.expired();
Chris@16:         }
Chris@16:         bool nolock_nograb_blocked() const
Chris@16:         {
Chris@16:           return nolock_nograb_connected() == false || blocked();
Chris@16:         }
Chris@16:         bool nolock_nograb_connected() const {return _connected;}
Chris@16:         // expose part of Lockable concept of mutex
Chris@16:         virtual void lock() = 0;
Chris@16:         virtual void unlock() = 0;
Chris@16: 
Chris@16:       protected:
Chris@16: 
Chris@16:         mutable bool _connected;
Chris@16:         weak_ptr<void> _weak_blocker;
Chris@16:       };
Chris@16: 
Chris@16:       template<typename GroupKey, typename SlotType, typename Mutex>
Chris@16:       class connection_body: public connection_body_base
Chris@16:       {
Chris@16:       public:
Chris@16:         typedef Mutex mutex_type;
Chris@16:         connection_body(const SlotType &slot_in):
Chris@16:           slot(slot_in)
Chris@16:         {
Chris@16:         }
Chris@16:         virtual ~connection_body() {}
Chris@16:         virtual bool connected() const
Chris@16:         {
Chris@16:           unique_lock<mutex_type> local_lock(_mutex);
Chris@16:           nolock_grab_tracked_objects(detail::null_output_iterator());
Chris@16:           return nolock_nograb_connected();
Chris@16:         }
Chris@16:         const GroupKey& group_key() const {return _group_key;}
Chris@16:         void set_group_key(const GroupKey &key) {_group_key = key;}
Chris@16:         bool nolock_slot_expired() const
Chris@16:         {
Chris@16:           bool expired = slot.expired();
Chris@16:           if(expired == true)
Chris@16:           {
Chris@16:             _connected = false;
Chris@16:           }
Chris@16:           return expired;
Chris@16:         }
Chris@16:         template<typename OutputIterator>
Chris@16:           void nolock_grab_tracked_objects(OutputIterator inserter) const
Chris@16:         {
Chris@16:           slot_base::tracked_container_type::const_iterator it;
Chris@16:           for(it = slot.tracked_objects().begin();
Chris@16:             it != slot.tracked_objects().end();
Chris@16:             ++it)
Chris@16:           {
Chris@16:             void_shared_ptr_variant locked_object
Chris@16:             (
Chris@16:               apply_visitor
Chris@16:               (
Chris@16:                 detail::lock_weak_ptr_visitor(),
Chris@16:                 *it
Chris@16:               )
Chris@16:             );
Chris@16:             if(apply_visitor(detail::expired_weak_ptr_visitor(), *it))
Chris@16:             {
Chris@16:               _connected = false;
Chris@16:               return;
Chris@16:             }
Chris@16:             *inserter++ = locked_object;
Chris@16:           }
Chris@16:         }
Chris@16:         // expose Lockable concept of mutex
Chris@16:         virtual void lock()
Chris@16:         {
Chris@16:           _mutex.lock();
Chris@16:         }
Chris@16:         virtual void unlock()
Chris@16:         {
Chris@16:           _mutex.unlock();
Chris@16:         }
Chris@16:         SlotType slot;
Chris@16:       private:
Chris@16:         mutable mutex_type _mutex;
Chris@16:         GroupKey _group_key;
Chris@16:       };
Chris@16:     }
Chris@16: 
Chris@16:     class shared_connection_block;
Chris@16: 
Chris@16:     class connection
Chris@16:     {
Chris@16:     public:
Chris@16:       friend class shared_connection_block;
Chris@16: 
Chris@16:       connection() {}
Chris@16:       connection(const connection &other): _weak_connection_body(other._weak_connection_body)
Chris@16:       {}
Chris@16:       connection(const boost::weak_ptr<detail::connection_body_base> &connectionBody):
Chris@16:         _weak_connection_body(connectionBody)
Chris@16:       {}
Chris@101:       
Chris@101:       // move support
Chris@101: #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
Chris@101:       connection(connection && other): _weak_connection_body(std::move(other._weak_connection_body))
Chris@101:       {
Chris@101:         // make sure other is reset, in case it is a scoped_connection (so it
Chris@101:         // won't disconnect on destruction after being moved away from).
Chris@101:         other._weak_connection_body.reset();
Chris@101:       }
Chris@101:       connection & operator=(connection && other)
Chris@101:       {
Chris@101:         if(&other == this) return *this;
Chris@101:         _weak_connection_body = std::move(other._weak_connection_body);
Chris@101:         // make sure other is reset, in case it is a scoped_connection (so it
Chris@101:         // won't disconnect on destruction after being moved away from).
Chris@101:         other._weak_connection_body.reset();
Chris@101:         return *this;
Chris@101:       }
Chris@101: #endif // !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
Chris@101:       connection & operator=(const connection & other)
Chris@101:       {
Chris@101:         if(&other == this) return *this;
Chris@101:         _weak_connection_body = other._weak_connection_body;
Chris@101:         return *this;
Chris@101:       }
Chris@101: 
Chris@16:       ~connection() {}
Chris@16:       void disconnect() const
Chris@16:       {
Chris@16:         boost::shared_ptr<detail::connection_body_base> connectionBody(_weak_connection_body.lock());
Chris@16:         if(connectionBody == 0) return;
Chris@16:         connectionBody->disconnect();
Chris@16:       }
Chris@16:       bool connected() const
Chris@16:       {
Chris@16:         boost::shared_ptr<detail::connection_body_base> connectionBody(_weak_connection_body.lock());
Chris@16:         if(connectionBody == 0) return false;
Chris@16:         return connectionBody->connected();
Chris@16:       }
Chris@16:       bool blocked() const
Chris@16:       {
Chris@16:         boost::shared_ptr<detail::connection_body_base> connectionBody(_weak_connection_body.lock());
Chris@16:         if(connectionBody == 0) return true;
Chris@16:         return connectionBody->blocked();
Chris@16:       }
Chris@16:       bool operator==(const connection& other) const
Chris@16:       {
Chris@16:         boost::shared_ptr<detail::connection_body_base> connectionBody(_weak_connection_body.lock());
Chris@16:         boost::shared_ptr<detail::connection_body_base> otherConnectionBody(other._weak_connection_body.lock());
Chris@16:         return connectionBody == otherConnectionBody;
Chris@16:       }
Chris@16:       bool operator!=(const connection& other) const
Chris@16:       {
Chris@16:         return !(*this == other);
Chris@16:       }
Chris@16:       bool operator<(const connection& other) const
Chris@16:       {
Chris@16:         boost::shared_ptr<detail::connection_body_base> connectionBody(_weak_connection_body.lock());
Chris@16:         boost::shared_ptr<detail::connection_body_base> otherConnectionBody(other._weak_connection_body.lock());
Chris@16:         return connectionBody < otherConnectionBody;
Chris@16:       }
Chris@16:       void swap(connection &other)
Chris@16:       {
Chris@16:         using std::swap;
Chris@16:         swap(_weak_connection_body, other._weak_connection_body);
Chris@16:       }
Chris@16:     protected:
Chris@16: 
Chris@16:       boost::weak_ptr<detail::connection_body_base> _weak_connection_body;
Chris@16:     };
Chris@16:     inline void swap(connection &conn1, connection &conn2)
Chris@16:     {
Chris@16:       conn1.swap(conn2);
Chris@16:     }
Chris@16: 
Chris@16:     class scoped_connection: public connection
Chris@16:     {
Chris@16:     public:
Chris@16:       scoped_connection() {}
Chris@16:       scoped_connection(const connection &other):
Chris@16:         connection(other)
Chris@16:       {}
Chris@16:       ~scoped_connection()
Chris@16:       {
Chris@16:         disconnect();
Chris@16:       }
Chris@16:       scoped_connection& operator=(const connection &rhs)
Chris@16:       {
Chris@16:         disconnect();
Chris@16:         connection::operator=(rhs);
Chris@16:         return *this;
Chris@16:       }
Chris@101: 
Chris@101:       // move support
Chris@101: #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
Chris@101:       scoped_connection(scoped_connection && other): connection(std::move(other))
Chris@101:       {
Chris@101:       }
Chris@101:       scoped_connection(connection && other): connection(std::move(other))
Chris@101:       {
Chris@101:       }
Chris@101:       scoped_connection & operator=(scoped_connection && other)
Chris@101:       {
Chris@101:         if(&other == this) return *this;
Chris@101:         disconnect();
Chris@101:         connection::operator=(std::move(other));
Chris@101:         return *this;
Chris@101:       }
Chris@101:       scoped_connection & operator=(connection && other)
Chris@101:       {
Chris@101:         if(&other == this) return *this;
Chris@101:         disconnect();
Chris@101:         connection::operator=(std::move(other));
Chris@101:         return *this;
Chris@101:       }
Chris@101: #endif // !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
Chris@101: 
Chris@16:       connection release()
Chris@16:       {
Chris@16:         connection conn(_weak_connection_body);
Chris@16:         _weak_connection_body.reset();
Chris@16:         return conn;
Chris@16:       }
Chris@16:     private:
Chris@16:       scoped_connection(const scoped_connection &other);
Chris@16:       scoped_connection& operator=(const scoped_connection &rhs);
Chris@16:     };
Chris@16:     // Sun 5.9 compiler doesn't find the swap for base connection class when
Chris@16:     // arguments are scoped_connection, so we provide this explicitly.
Chris@16:     inline void swap(scoped_connection &conn1, scoped_connection &conn2)
Chris@16:     {
Chris@16:       conn1.swap(conn2);
Chris@16:     }
Chris@16:   }
Chris@16: }
Chris@16: 
Chris@16: #endif  // BOOST_SIGNALS2_CONNECTION_HPP