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Renamed enable_shared_from_this2 to enable_shared_from_raw and

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added shared_from_raw free function.  These changes fix the pointer 
value in shared_ptr which were obtained before an external shared_ptr has
taken ownership of the object (for example when a shared_ptr to
this is obtained in an object's constructor).



[SVN r57197]
This commit is contained in:
Frank Mori Hess
2009-10-28 19:10:47 +00:00
parent e824e23ec2
commit 32eb028e13
4 changed files with 171 additions and 154 deletions
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157
include/boost/smart_ptr/enable_shared_from_raw.hpp Normal file
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@ -0,0 +1,157 @@
#ifndef BOOST_ENABLE_SHARED_FROM_RAW_HPP_INCLUDED
#define BOOST_ENABLE_SHARED_FROM_RAW_HPP_INCLUDED
//
// enable_shared_from_raw.hpp
//
// Copyright 2002, 2009 Peter Dimov
// Copyright 2008-2009 Frank Mori Hess
//
// Distributed under 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
//
#include <boost/config.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/weak_ptr.hpp>
#include <boost/assert.hpp>
#include <boost/detail/workaround.hpp>
namespace boost
{
template<typename T> boost::shared_ptr<T> shared_from_raw(T *);
namespace detail
{
template< class X, class Y > inline void sp_enable_shared_from_this( boost::shared_ptr<X> * ppx, Y const * py, boost::enable_shared_from_raw const * pe );
class esft2_deleter_wrapper
{
private:
shared_ptr<void> deleter_;
public:
esft2_deleter_wrapper()
{
}
template< class T > void set_deleter( shared_ptr<T> const & deleter )
{
deleter_ = deleter;
}
template< class T> void operator()( T* )
{
BOOST_ASSERT( deleter_.use_count() <= 1 );
deleter_.reset();
}
};
} // namespace detail
class enable_shared_from_raw
{
protected:
enable_shared_from_raw()
{
}
enable_shared_from_raw( enable_shared_from_raw const & )
{
}
enable_shared_from_raw & operator=( enable_shared_from_raw const & )
{
return *this;
}
~enable_shared_from_raw()
{
BOOST_ASSERT( shared_this_.use_count() <= 1 ); // make sure no dangling shared_ptr objects exist
}
private:
mutable weak_ptr<void> weak_this_;
mutable shared_ptr<void> shared_this_;
private:
void init_weak_once() const
{
if( weak_this_.expired() )
{
shared_this_.reset( static_cast<void*>(0), detail::esft2_deleter_wrapper() );
weak_this_ = shared_this_;
}
}
#ifdef BOOST_NO_MEMBER_TEMPLATE_FRIENDS
public:
#else
private:
template<class Y> friend class shared_ptr;
template<typename T> friend boost::shared_ptr<T> shared_from_raw(T *);
template< class X, class Y > friend inline void detail::sp_enable_shared_from_this( boost::shared_ptr<X> * ppx, Y const * py, boost::enable_shared_from_raw const * pe );
#endif
shared_ptr<void> shared_from_this()
{
init_weak_once();
return shared_ptr<void>( weak_this_ );
}
shared_ptr<const void> shared_from_this() const
{
init_weak_once();
return shared_ptr<const void>( weak_this_ );
}
// Note: invoked automatically by shared_ptr; do not call
template<class X, class Y> void _internal_accept_owner( shared_ptr<X> * ppx, Y * py ) const
{
BOOST_ASSERT( ppx != 0 );
if( weak_this_.expired() )
{
weak_this_ = *ppx;
}
else if( shared_this_.use_count() != 0 )
{
BOOST_ASSERT( ppx->unique() ); // no weak_ptrs should exist either, but there's no way to check that
detail::esft2_deleter_wrapper * pd = boost::get_deleter<detail::esft2_deleter_wrapper>( shared_this_ );
BOOST_ASSERT( pd != 0 );
pd->set_deleter( *ppx );
ppx->reset( shared_this_, ppx->get() );
shared_this_.reset();
}
}
};
template<typename T>
boost::shared_ptr<T> shared_from_raw(T *p)
{
return boost::shared_ptr<T>(p->enable_shared_from_raw::shared_from_this(), p);
}
namespace detail
{
template< class X, class Y > inline void sp_enable_shared_from_this( boost::shared_ptr<X> * ppx, Y const * py, boost::enable_shared_from_raw const * pe )
{
if( pe != 0 )
{
pe->_internal_accept_owner( ppx, const_cast< Y* >( py ) );
}
}
} // namepsace detail
} // namespace boost
#endif // #ifndef BOOST_ENABLE_SHARED_FROM_RAW_HPP_INCLUDED

132
include/boost/smart_ptr/enable_shared_from_this2.hpp
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@ -1,132 +0,0 @@
#ifndef BOOST_ENABLE_SHARED_FROM_THIS2_HPP_INCLUDED
#define BOOST_ENABLE_SHARED_FROM_THIS2_HPP_INCLUDED
//
// enable_shared_from_this2.hpp
//
// Copyright 2002, 2009 Peter Dimov
// Copyright 2008 Frank Mori Hess
//
// Distributed under 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
//
#include <boost/config.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/assert.hpp>
#include <boost/detail/workaround.hpp>
namespace boost
{
namespace detail
{
class esft2_deleter_wrapper
{
private:
shared_ptr<void> deleter_;
public:
esft2_deleter_wrapper()
{
}
template< class T > void set_deleter( shared_ptr<T> const & deleter )
{
deleter_ = deleter;
}
template< class T> void operator()( T* )
{
BOOST_ASSERT( deleter_.use_count() <= 1 );
deleter_.reset();
}
};
} // namespace detail
template< class T > class enable_shared_from_this2
{
protected:
enable_shared_from_this2()
{
}
enable_shared_from_this2( enable_shared_from_this2 const & )
{
}
enable_shared_from_this2 & operator=( enable_shared_from_this2 const & )
{
return *this;
}
~enable_shared_from_this2()
{
BOOST_ASSERT( shared_this_.use_count() <= 1 ); // make sure no dangling shared_ptr objects exist
}
private:
mutable weak_ptr<T> weak_this_;
mutable shared_ptr<T> shared_this_;
public:
shared_ptr<T> shared_from_this()
{
init_weak_once();
return shared_ptr<T>( weak_this_ );
}
shared_ptr<T const> shared_from_this() const
{
init_weak_once();
return shared_ptr<T>( weak_this_ );
}
private:
void init_weak_once() const
{
if( weak_this_._empty() )
{
shared_this_.reset( static_cast< T* >( 0 ), detail::esft2_deleter_wrapper() );
weak_this_ = shared_this_;
}
}
public: // actually private, but avoids compiler template friendship issues
// Note: invoked automatically by shared_ptr; do not call
template<class X, class Y> void _internal_accept_owner( shared_ptr<X> * ppx, Y * py ) const
{
BOOST_ASSERT( ppx != 0 );
if( weak_this_.use_count() == 0 )
{
weak_this_ = shared_ptr<T>( *ppx, py );
}
else if( shared_this_.use_count() != 0 )
{
BOOST_ASSERT( ppx->unique() ); // no weak_ptrs should exist either, but there's no way to check that
detail::esft2_deleter_wrapper * pd = boost::get_deleter<detail::esft2_deleter_wrapper>( shared_this_ );
BOOST_ASSERT( pd != 0 );
pd->set_deleter( *ppx );
ppx->reset( shared_this_, ppx->get() );
shared_this_.reset();
}
}
};
} // namespace boost
#endif // #ifndef BOOST_ENABLE_SHARED_FROM_THIS2_HPP_INCLUDED

10
include/boost/smart_ptr/shared_ptr.hpp
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@ -61,7 +61,7 @@ namespace boost
template<class T> class shared_ptr;
template<class T> class weak_ptr;
template<class T> class enable_shared_from_this;
template<class T> class enable_shared_from_this2;
class enable_shared_from_raw;
namespace detail
{
@ -110,13 +110,7 @@ template< class X, class Y, class T > inline void sp_enable_shared_from_this( bo
}
}
template< class X, class Y, class T > inline void sp_enable_shared_from_this( boost::shared_ptr<X> * ppx, Y const * py, boost::enable_shared_from_this2< T > const * pe )
{
if( pe != 0 )
{
pe->_internal_accept_owner( ppx, const_cast< Y* >( py ) );
}
}
template< class X, class Y > inline void sp_enable_shared_from_this( boost::shared_ptr<X> * ppx, Y const * py, boost::enable_shared_from_raw const * pe );
#ifdef _MANAGED

26
test/esft_constructor_test.cpp
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@ -13,14 +13,13 @@
// See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//
#include <boost/smart_ptr/enable_shared_from_this2.hpp>
#include <boost/smart_ptr/enable_shared_from_raw.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/weak_ptr.hpp>
#include <boost/detail/lightweight_test.hpp>
#include <memory>
class X: public boost::enable_shared_from_this2< X >
class X: public boost::enable_shared_from_raw
{
private:
@ -42,7 +41,7 @@ public:
explicit X( int expected, boost::shared_ptr<X> *early_px = 0 ): destroyed_( 0 ), deleted_( 0 ), expected_( expected )
{
++instances;
if( early_px ) *early_px = shared_from_this();
if( early_px ) *early_px = shared_from_raw(this);
}
~X()
@ -75,7 +74,7 @@ bool are_shared_owners(const boost::shared_ptr<T> &a, const boost::shared_ptr<U>
return !(a < b) && !(b < a);
}
struct Y: public boost::enable_shared_from_this2<Y>
struct Y: public boost::enable_shared_from_raw
{};
int main()
@ -87,6 +86,7 @@ int main()
X* x = new X( 1, &early_px );
BOOST_TEST( early_px.use_count() > 0 );
BOOST_TEST( boost::get_deleter<X::deleter_type>(early_px) == 0 );
BOOST_TEST( early_px.get() == x );
boost::shared_ptr<X> px( x, &X::deleter2 );
BOOST_TEST( early_px.use_count() == 2 && px.use_count() == 2 );
BOOST_TEST(are_shared_owners(early_px, px));
@ -117,7 +117,7 @@ int main()
{
boost::shared_ptr<X> early_px;
X x( 1, &early_px );
X x( 2, &early_px );
BOOST_TEST( early_px.use_count() > 0 );
boost::shared_ptr<X> px( &x, &X::deleter );
BOOST_TEST( early_px.use_count() == 2 && px.use_count() == 2 );
@ -125,13 +125,11 @@ int main()
BOOST_TEST( px.use_count() == 1 );
BOOST_TEST( X::instances == 1 );
px.reset();
try
{
x.shared_from_this();
BOOST_ERROR("x did not throw bad_weak_ptr");
}
catch( const boost::bad_weak_ptr & )
{}
// test reinitialization after all shared_ptr have expired
early_px = shared_from_raw(&x);
px.reset( &x, &X::deleter );
BOOST_TEST(are_shared_owners(early_px, px));
early_px.reset();
}
BOOST_TEST( X::instances == 0 );
@ -157,7 +155,7 @@ int main()
px.reset();
try
{
y.shared_from_this();
shared_from_raw(&y);
}
catch( const boost::bad_weak_ptr & )
{