Loki/src/SmartPtr.cpp
rich_sposato 4ac9e4f44d Added text of MIT License.
git-svn-id: svn://svn.code.sf.net/p/loki-lib/code/trunk@1116 7ec92016-0320-0410-acc4-a06ded1c099a
2011-09-23 00:46:54 +00:00

368 lines
9.4 KiB
C++

////////////////////////////////////////////////////////////////////////////////
// The Loki Library
// Copyright (c) 2001 by Andrei Alexandrescu
// Copyright (c) 2006 Richard Sposato
// This code accompanies the book:
// Alexandrescu, Andrei. "Modern C++ Design: Generic Programming and Design
// Patterns Applied". Copyright (c) 2001. Addison-Wesley.
// Code covered by the MIT License
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
////////////////////////////////////////////////////////////////////////////////
// $Id$
#include <loki/SmartPtr.h>
#include <cassert>
#include <stdexcept>
#include <string>
//#define DO_EXTRA_LOKI_TESTS
#ifdef DO_EXTRA_LOKI_TESTS
#include <iostream>
#endif
// ----------------------------------------------------------------------------
namespace Loki
{
namespace Private
{
// ----------------------------------------------------------------------------
void DeleteArrayBase::Swap( DeleteArrayBase & rhs )
{
assert( NULL != this );
const size_t temp = m_itemCount;
m_itemCount = rhs.m_itemCount;
rhs.m_itemCount = temp;
}
// ----------------------------------------------------------------------------
void DeleteArrayBase::OnInit( const void * p ) const
{
assert( NULL != this );
if ( NULL == p )
{
assert( 0 == m_itemCount );
}
else
{
assert( 0 < m_itemCount );
}
}
// ----------------------------------------------------------------------------
void DeleteArrayBase::OnCheckRange( size_t index ) const
{
assert( NULL != this );
if ( index < m_itemCount )
return;
const ::std::string message( "index out of range in ::Loki::DeleteArrayBase::OnCheckRange" );
throw ::std::out_of_range( message );
}
// ----------------------------------------------------------------------------
RefLinkedBase::RefLinkedBase( const RefLinkedBase & rhs ) :
prev_( &rhs ),
next_( rhs.next_ )
{
prev_->next_ = this;
next_->prev_ = this;
#ifdef DO_EXTRA_LOKI_TESTS
assert( prev_->HasPrevNode( this ) );
assert( next_->HasNextNode( this ) );
assert( CountPrevCycle( this ) == CountNextCycle( this ) );
#endif
}
// ----------------------------------------------------------------------------
bool RefLinkedBase::Release()
{
#ifdef DO_EXTRA_LOKI_TESTS
assert( prev_->HasPrevNode( this ) );
assert( next_->HasNextNode( this ) );
assert( CountPrevCycle( this ) == CountNextCycle( this ) );
#endif
if ( NULL == next_ )
{
assert( NULL == prev_ );
// Return false so it does not try to destroy shared object
// more than once.
return false;
}
else if (next_ == this)
{
assert(prev_ == this);
// Set these to NULL to prevent re-entrancy.
prev_ = NULL;
next_ = NULL;
return true;
}
#ifdef DO_EXTRA_LOKI_TESTS
assert( this != prev_ );
assert( NULL != prev_ );
assert( prev_->HasPrevNode( this ) );
assert( next_->HasNextNode( this ) );
#endif
prev_->next_ = next_;
next_->prev_ = prev_;
#ifdef DO_EXTRA_LOKI_TESTS
next_ = this;
prev_ = this;
assert( 1 == CountNextCycle( this ) );
assert( 1 == CountPrevCycle( this ) );
#endif
return false;
}
// ----------------------------------------------------------------------------
void RefLinkedBase::Swap(RefLinkedBase& rhs)
{
#ifdef DO_EXTRA_LOKI_TESTS
assert( prev_->HasPrevNode( this ) );
assert( next_->HasNextNode( this ) );
assert( CountPrevCycle( this ) == CountNextCycle( this ) );
#endif
if (next_ == this)
{
assert(prev_ == this);
if (rhs.next_ == &rhs)
{
assert(rhs.prev_ == &rhs);
// both lists are empty, nothing 2 do
return;
}
prev_ = rhs.prev_;
next_ = rhs.next_;
prev_->next_ = next_->prev_ = this;
rhs.next_ = rhs.prev_ = &rhs;
return;
}
if (rhs.next_ == &rhs)
{
rhs.Swap(*this);
return;
}
if (next_ == &rhs ) // rhs is next neighbour
{
if ( prev_ == &rhs )
return; // cycle of 2 pointers - no need to swap.
std::swap(prev_, next_);
std::swap(rhs.prev_, rhs.next_);
std::swap(rhs.prev_, next_);
std::swap(rhs.prev_->next_,next_->prev_);
}
else if ( prev_ == &rhs ) // rhs is prev neighbor
{
if ( next_ == &rhs )
return; // cycle of 2 pointers - no need to swap.
std::swap( prev_, next_ );
std::swap( rhs.next_, rhs.prev_ );
std::swap( rhs.next_, prev_ );
std::swap( rhs.next_->prev_, prev_->next_ );
}
else // not neighhbors
{
std::swap(prev_, rhs.prev_);
std::swap(next_, rhs.next_);
std::swap(prev_->next_, rhs.prev_->next_);
std::swap(next_->prev_, rhs.next_->prev_);
}
#ifdef DO_EXTRA_LOKI_TESTS
assert( next_ == this ? prev_ == this : prev_ != this);
assert( prev_ == this ? next_ == this : next_ != this);
assert( prev_->HasPrevNode( this ) );
assert( next_->HasNextNode( this ) );
assert( CountPrevCycle( this ) == CountNextCycle( this ) );
assert( rhs.prev_->HasPrevNode( &rhs ) );
assert( rhs.next_->HasNextNode( &rhs ) );
assert( CountPrevCycle( &rhs ) == CountNextCycle( &rhs ) );
#endif
}
// ----------------------------------------------------------------------------
unsigned int RefLinkedBase::CountPrevCycle( const RefLinkedBase * pThis )
{
if ( NULL == pThis )
return 0;
const RefLinkedBase * p = pThis->prev_;
if ( NULL == p )
return 0;
if ( pThis == p )
return 1;
unsigned int count = 1;
do
{
p = p->prev_;
++count;
} while ( p != pThis );
return count;
}
// ----------------------------------------------------------------------------
unsigned int RefLinkedBase::CountNextCycle( const RefLinkedBase * pThis )
{
if ( NULL == pThis )
return 0;
const RefLinkedBase * p = pThis->next_;
if ( NULL == p )
return 0;
if ( pThis == p )
return 1;
unsigned int count = 1;
while ( p != pThis )
{
p = p->next_;
++count;
}
return count;
}
// ----------------------------------------------------------------------------
bool RefLinkedBase::HasPrevNode( const RefLinkedBase * p ) const
{
if ( this == p )
return true;
const RefLinkedBase * prev = prev_;
if ( NULL == prev )
return false;
while ( prev != this )
{
if ( p == prev )
return true;
prev = prev->prev_;
}
return false;
}
// ----------------------------------------------------------------------------
bool RefLinkedBase::HasNextNode( const RefLinkedBase * p ) const
{
if ( this == p )
return true;
const RefLinkedBase * next = next_;
if ( NULL == next )
return false;
while ( next != this )
{
if ( p == next )
return true;
next = next->next_;
}
return false;
}
// ----------------------------------------------------------------------------
bool RefLinkedBase::Merge( RefLinkedBase & rhs )
{
if ( NULL == next_ )
{
assert( NULL == prev_ );
return false;
}
RefLinkedBase * prhs = &rhs;
if ( prhs == this )
return true;
if ( NULL == prhs->next_ )
{
assert( NULL == prhs->prev_ );
return true;
}
assert( CountPrevCycle( this ) == CountNextCycle( this ) );
assert( CountPrevCycle( prhs ) == CountNextCycle( prhs ) );
// If rhs node is already in this cycle, then no need to merge.
if ( HasPrevNode( &rhs ) )
{
assert( HasNextNode( &rhs ) );
return true;
}
if ( prhs == prhs->next_ )
{
/// rhs is in a cycle with 1 node.
assert( prhs->prev_ == prhs );
prhs->prev_ = prev_;
prhs->next_ = this;
prev_->next_ = prhs;
prev_ = prhs;
}
else if ( this == next_ )
{
/// this is in a cycle with 1 node.
assert( prev_ == this );
prev_ = prhs->prev_;
next_ = prhs;
prhs->prev_->next_ = this;
prhs->prev_ = this;
}
else
{
next_->prev_ = prhs->prev_;
prhs->prev_->next_ = prev_;
next_ = prhs;
prhs->prev_ = this;
}
assert( CountPrevCycle( this ) == CountNextCycle( this ) );
return true;
}
// ----------------------------------------------------------------------------
} // end namespace Private
} // end namespace Loki