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Reduce enable_shared_from_this overhead (replace _internal_shared_ptr by _internal_shared_count)

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[SVN r44730]
This commit is contained in:
Daniel Frey
2008-04-23 06:12:39 +00:00
parent 93545d5cf2
commit 77f2d3f614
1 changed files with 10 additions and 11 deletions
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21
include/boost/enable_shared_from_this.hpp
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@@ -27,12 +27,11 @@ template<class T> class enable_shared_from_this
// to use lazy initialization // to use lazy initialization
void init_internal_shared_once() const void init_internal_shared_once() const
{ {
if( !owned() && _internal_shared_this.get() == 0 ) if( !owned() && _internal_shared_count.empty() )
{ {
T * p = dynamic_cast<T *>(const_cast<enable_shared_from_this*>(this)); T * p = dynamic_cast<T *>(const_cast<enable_shared_from_this*>(this));
_internal_shared_this = shared_ptr<T>( p, detail::sp_deleter_wrapper() ); detail::shared_count( p, detail::sp_deleter_wrapper() ).swap(_internal_shared_count);
BOOST_ASSERT(_internal_shared_this.get() == this); _internal_weak_count = _internal_shared_count;
_internal_weak_count = _internal_shared_this.get_shared_count();
} }
} }
@@ -41,8 +40,7 @@ template<class T> class enable_shared_from_this
return _owned; return _owned;
} }
typedef T _internal_element_type; // for bcc 5.5.1 mutable detail::shared_count _internal_shared_count;
mutable shared_ptr<_internal_element_type> _internal_shared_this;
mutable detail::weak_count _internal_weak_count; mutable detail::weak_count _internal_weak_count;
mutable bool _owned; mutable bool _owned;
@@ -69,7 +67,7 @@ protected:
// make sure no dangling shared_ptr objects were created by the // make sure no dangling shared_ptr objects were created by the
// user calling shared_from_this() but never passing ownership of the object // user calling shared_from_this() but never passing ownership of the object
// to a shared_ptr. // to a shared_ptr.
BOOST_ASSERT(owned() || _internal_shared_this.use_count() <= 1); BOOST_ASSERT(owned() || _internal_shared_count.use_count() <= 1);
} }
public: public:
@@ -93,18 +91,19 @@ public:
{ {
if( !_owned ) if( !_owned )
{ {
if( !_internal_shared_this ) if( _internal_shared_count.empty() )
{ {
_internal_weak_count = owner.get_shared_count(); _internal_weak_count = owner.get_shared_count();
}else }else
{ {
BOOST_ASSERT(owner.unique()); // no weak_ptrs to owner should exist either, but there's no way to check that BOOST_ASSERT(owner.unique()); // no weak_ptrs to owner should exist either, but there's no way to check that
detail::sp_deleter_wrapper * pd = get_deleter<detail::sp_deleter_wrapper>(_internal_shared_this); typedef detail::sp_deleter_wrapper D;
D * pd = static_cast<D *>(_internal_shared_count.get_deleter(BOOST_SP_TYPEID(D)));
BOOST_ASSERT( pd != 0 ); BOOST_ASSERT( pd != 0 );
pd->set_deleter(owner); pd->set_deleter(owner);
owner.reset( _internal_shared_this, owner.get() ); shared_ptr<U>( _internal_shared_count, owner.get() ).swap( owner );
_internal_shared_this.reset(); detail::shared_count().swap(_internal_shared_count);
} }
_owned = true; _owned = true;
} }