ceph/src/boost/libs/signals2/include/boost/signals2/slot_base.hpp

   1 // Boost.Signals2 library
   2
   3 // Copyright Frank Mori Hess 2007-2008.
   4 // Copyright Timmo Stange 2007.
   5 // Copyright Douglas Gregor 2001-2004. Use, modification and
   6 // distribution is subject to the Boost Software License, Version
   7 // 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   8 // http://www.boost.org/LICENSE_1_0.txt)
   9
  10 // For more information, see http://www.boost.org
  11
  12 #ifndef BOOST_SIGNALS2_SLOT_BASE_HPP
  13 #define BOOST_SIGNALS2_SLOT_BASE_HPP
  14
  15 #include <boost/shared_ptr.hpp>
  16 #include <boost/weak_ptr.hpp>
  17 #include <boost/signals2/detail/foreign_ptr.hpp>
  18 #include <boost/signals2/expired_slot.hpp>
  19 #include <boost/signals2/signal_base.hpp>
  20 #include <boost/variant/apply_visitor.hpp>
  21 #include <boost/variant/variant.hpp>
  22 #include <vector>
  23
  24 namespace boost
  25 {
  26   namespace signals2
  27   {
  28     namespace detail
  29     {
  30       class tracked_objects_visitor;
  31       class trackable_pointee;
  32
  33       typedef boost::variant<boost::weak_ptr<trackable_pointee>, boost::weak_ptr<void>, detail::foreign_void_weak_ptr > void_weak_ptr_variant;
  34       typedef boost::variant<boost::shared_ptr<void>, detail::foreign_void_shared_ptr > void_shared_ptr_variant;
  35       class lock_weak_ptr_visitor
  36       {
  37       public:
  38         typedef void_shared_ptr_variant result_type;
  39         template<typename WeakPtr>
  40         result_type operator()(const WeakPtr &wp) const
  41         {
  42           return wp.lock();
  43         }
  44         // overload to prevent incrementing use count of shared_ptr associated
  45         // with signals2::trackable objects
  46         result_type operator()(const weak_ptr<trackable_pointee> &) const
  47         {
  48           return boost::shared_ptr<void>();
  49         }
  50       };
  51       class expired_weak_ptr_visitor
  52       {
  53       public:
  54         typedef bool result_type;
  55         template<typename WeakPtr>
  56         bool operator()(const WeakPtr &wp) const
  57         {
  58           return wp.expired();
  59         }
  60       };
  61     }
  62
  63     class slot_base
  64     {
  65     public:
  66       typedef std::vector<detail::void_weak_ptr_variant> tracked_container_type;
  67       typedef std::vector<detail::void_shared_ptr_variant> locked_container_type;
  68
  69       const tracked_container_type& tracked_objects() const {return _tracked_objects;}
  70     #ifndef BOOST_NO_EXCEPTIONS
  71       locked_container_type lock() const
  72       {
  73         locked_container_type locked_objects;
  74         tracked_container_type::const_iterator it;
  75         for(it = tracked_objects().begin(); it != tracked_objects().end(); ++it)
  76         {
  77           locked_objects.push_back(apply_visitor(detail::lock_weak_ptr_visitor(), *it));
  78           if(apply_visitor(detail::expired_weak_ptr_visitor(), *it))
  79           {
  80             throw expired_slot();
  81           }
  82         }
  83         return locked_objects;
  84       }
  85     #endif
  86       bool expired() const
  87       {
  88         tracked_container_type::const_iterator it;
  89         for(it = tracked_objects().begin(); it != tracked_objects().end(); ++it)
  90         {
  91           if(apply_visitor(detail::expired_weak_ptr_visitor(), *it)) return true;
  92         }
  93         return false;
  94       }
  95     protected:
  96       friend class detail::tracked_objects_visitor;
  97
  98       void track_signal(const signal_base &signal)
  99       {
 100         _tracked_objects.push_back(signal.lock_pimpl());
 101       }
 102
 103       tracked_container_type _tracked_objects;
 104     };
 105   }
 106 } // end namespace boost
 107
 108 #endif // BOOST_SIGNALS2_SLOT_BASE_HPP