/////////////////////////////////////////////////////////////////////////////
-// Name: No names yet.
-// Purpose: Contrib. demo
+// Name: garbagec.cpp
+// Purpose: Garbage collection algorithm for optimizing refresh.
// Author: Aleksandras Gluchovas
// Modified by:
// Created: 18/10/98
// RCS-ID: $Id$
// Copyright: (c) Aleksandras Gluchovas
-// Licence: wxWindows license
+// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
inline static GCItem& node_to_item( wxNode* pNode )
{
- return *( (GCItem*)(pNode->Data()) );
+ return *( (GCItem*)(pNode->Data()) );
}
GarbageCollector::~GarbageCollector()
{
- Reset();
+ Reset();
}
/*** GC alg. helpers ***/
void GarbageCollector::DestroyItemList( wxList& lst )
{
- wxNode* pNode = lst.First();
+ wxNode* pNode = lst.First();
- while( pNode )
- {
- delete &node_to_item( pNode );
+ while( pNode )
+ {
+ delete &node_to_item( pNode );
- pNode = pNode->Next();
- }
+ pNode = pNode->Next();
+ }
- lst.Clear();
+ lst.Clear();
}
wxNode* GarbageCollector::FindItemNode( void* pForObj )
{
- wxNode* pNode = mAllNodes.First();
+ wxNode* pNode = mAllNodes.First();
- while( pNode )
- {
- if ( node_to_item( pNode ).mpObj == pForObj )
+ while( pNode )
+ {
+ if ( node_to_item( pNode ).mpObj == pForObj )
- return pNode;
+ return pNode;
- pNode = pNode->Next();
- }
+ pNode = pNode->Next();
+ }
- int avoidCompilerWarning = 0;
- wxASSERT(avoidCompilerWarning); // DBG:: item should be present
+ int avoidCompilerWarning = 0;
+ wxASSERT(avoidCompilerWarning); // DBG:: item should be present
- return 0;
+ return 0;
}
wxNode* GarbageCollector::FindReferenceFreeItemNode()
{
- wxNode* pNode = mAllNodes.First();
+ wxNode* pNode = mAllNodes.First();
- while( pNode )
- {
- if ( node_to_item( pNode ).mRefs.Number() == 0 )
+ while( pNode )
+ {
+ if ( node_to_item( pNode ).mRefs.Number() == 0 )
- return pNode;
+ return pNode;
- pNode = pNode->Next();
- }
+ pNode = pNode->Next();
+ }
- return 0;
+ return 0;
}
void GarbageCollector::RemoveReferencesToNode( wxNode* pItemNode )
{
- wxNode* pNode = mAllNodes.First();
+ wxNode* pNode = mAllNodes.First();
- while( pNode )
- {
- wxList& refLst = node_to_item( pNode ).mRefs;
- wxNode* pRefNode = refLst.First();
+ while( pNode )
+ {
+ wxList& refLst = node_to_item( pNode ).mRefs;
+ wxNode* pRefNode = refLst.First();
- while( pRefNode )
- {
- if ( pRefNode->Data() == (wxObject*)pItemNode )
- {
- wxNode* pNext = pRefNode->Next();
+ while( pRefNode )
+ {
+ if ( pRefNode->Data() == (wxObject*)pItemNode )
+ {
+ wxNode* pNext = pRefNode->Next();
- refLst.DeleteNode( pRefNode );
+ refLst.DeleteNode( pRefNode );
- pRefNode = pNext;
+ pRefNode = pNext;
- continue;
- }
- else pRefNode = pRefNode->Next();
- }
+ continue;
+ }
+ else pRefNode = pRefNode->Next();
+ }
- pNode = pNode->Next();
- }
+ pNode = pNode->Next();
+ }
}
void GarbageCollector::ResolveReferences()
{
- wxNode* pNode = mAllNodes.First();
+ wxNode* pNode = mAllNodes.First();
- while( pNode )
- {
- GCItem& item = node_to_item( pNode );
+ while( pNode )
+ {
+ GCItem& item = node_to_item( pNode );
- wxNode* pRefNode = item.mRefs.First();
+ wxNode* pRefNode = item.mRefs.First();
- while( pRefNode )
- {
- pRefNode->SetData( (wxObject*) FindItemNode( (void*)pRefNode->Data() ) );
+ while( pRefNode )
+ {
+ pRefNode->SetData( (wxObject*) FindItemNode( (void*)pRefNode->Data() ) );
- pRefNode = pRefNode->Next();
- }
+ pRefNode = pRefNode->Next();
+ }
- pNode = pNode->Next();
- }
+ pNode = pNode->Next();
+ }
}
void GarbageCollector::AddObject( void* pObj, int refCnt )
{
- // FOR NOW:: initial ref-count is not used
+ // FOR NOW:: initial ref-count is not used
- GCItem* pItem = new GCItem();
+ GCItem* pItem = new GCItem();
- pItem->mpObj = pObj;
+ pItem->mpObj = pObj;
- mAllNodes.Append( (wxObject*) pItem );
+ mAllNodes.Append( (wxObject*) pItem );
}
void GarbageCollector::AddDependency( void* pObj, void* pDependsOnObj )
{
- node_to_item( FindItemNode( pObj ) ).mRefs.Append( (wxObject*)pDependsOnObj );
+ node_to_item( FindItemNode( pObj ) ).mRefs.Append( (wxObject*)pDependsOnObj );
}
/*** GC alg. implementation ***/
void GarbageCollector::ArrangeCollection()
{
- ResolveReferences();
+ ResolveReferences();
- do
- {
- // find node, which does not depend on anything
+ do
+ {
+ // find node, which does not depend on anything
- wxNode* pItemNode = FindReferenceFreeItemNode();
+ wxNode* pItemNode = FindReferenceFreeItemNode();
- if ( pItemNode )
- {
- // append it to the list, where items are contained
- // in the increasing order of dependencies
+ if ( pItemNode )
+ {
+ // append it to the list, where items are contained
+ // in the increasing order of dependencies
- mRegularLst.Append( pItemNode->Data() );
+ mRegularLst.Append( pItemNode->Data() );
- mAllNodes.DeleteNode( pItemNode );
+ mAllNodes.DeleteNode( pItemNode );
- // remove references to this current "least-dependent" node
- // from reference lists of all the other nodes
+ // remove references to this current "least-dependent" node
+ // from reference lists of all the other nodes
- RemoveReferencesToNode( pItemNode );
- }
- else
- {
- // otherwise, what is left - all nodes, which
- // are involved into cycled chains (rings)
+ RemoveReferencesToNode( pItemNode );
+ }
+ else
+ {
+ // otherwise, what is left - all nodes, which
+ // are involved into cycled chains (rings)
- wxNode* pNode = mAllNodes.First();
+ wxNode* pNode = mAllNodes.First();
- while( pNode )
- {
- mCycledLst.Append( pNode->Data() );
+ while( pNode )
+ {
+ mCycledLst.Append( pNode->Data() );
- pNode = pNode->Next();
- }
+ pNode = pNode->Next();
+ }
- break;
- }
+ mAllNodes.Clear();
+ break;
+ }
- // continue search for "least-dependent" nodes
+ // continue search for "least-dependent" nodes
- } while(1);
+ } while(1);
}
wxList& GarbageCollector::GetRegularObjects()
{
- return mRegularLst;
+ return mRegularLst;
}
wxList& GarbageCollector::GetCycledObjects()
{
- return mCycledLst;
+ return mCycledLst;
}
void GarbageCollector::Reset()
{
- DestroyItemList( mAllNodes );
-
- mRegularLst.Clear();
- mCycledLst.Clear();
+ DestroyItemList( mAllNodes );
+ DestroyItemList( mRegularLst );
+ DestroyItemList( mCycledLst );
}
projects / wxWidgets.git / blobdiff