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8e08b761 JS |
1 | ///////////////////////////////////////////////////////////////////////////// |
2 | // Name: No names yet. | |
3 | // Purpose: Contrib. demo | |
4 | // Author: Aleksandras Gluchovas | |
5 | // Modified by: | |
6 | // Created: 18/10/98 | |
7 | // RCS-ID: $Id$ | |
8 | // Copyright: (c) Aleksandras Gluchovas | |
9 | // Licence: wxWindows license | |
10 | ///////////////////////////////////////////////////////////////////////////// | |
11 | ||
12 | ||
13 | #ifdef __GNUG__ | |
14 | #pragma implementation "garbagec.h" | |
15 | #endif | |
16 | ||
17 | // For compilers that support precompilation, includes "wx/wx.h". | |
18 | #include "wx/wxprec.h" | |
19 | ||
20 | #ifdef __BORLANDC__ | |
21 | #pragma hdrstop | |
22 | #endif | |
23 | ||
24 | ||
25 | #ifndef WX_PRECOMP | |
26 | #include "wx/wx.h" | |
27 | #endif | |
28 | ||
29 | #include "wx/fl/garbagec.h" | |
30 | ||
31 | /***** Implementation for class GarbageCollector *****/ | |
32 | ||
33 | inline static GCItem& node_to_item( wxNode* pNode ) | |
34 | { | |
35 | return *( (GCItem*)(pNode->Data()) ); | |
36 | } | |
37 | ||
38 | GarbageCollector::~GarbageCollector() | |
39 | { | |
40 | Reset(); | |
41 | } | |
42 | ||
43 | /*** GC alg. helpers ***/ | |
44 | ||
45 | void GarbageCollector::DestroyItemList( wxList& lst ) | |
46 | { | |
47 | wxNode* pNode = lst.First(); | |
48 | ||
49 | while( pNode ) | |
50 | { | |
51 | delete &node_to_item( pNode ); | |
52 | ||
53 | pNode = pNode->Next(); | |
54 | } | |
55 | ||
56 | lst.Clear(); | |
57 | } | |
58 | ||
59 | wxNode* GarbageCollector::FindItemNode( void* pForObj ) | |
60 | { | |
61 | wxNode* pNode = mAllNodes.First(); | |
62 | ||
63 | while( pNode ) | |
64 | { | |
65 | if ( node_to_item( pNode ).mpObj == pForObj ) | |
66 | ||
67 | return pNode; | |
68 | ||
69 | pNode = pNode->Next(); | |
70 | } | |
71 | ||
72 | int avoidCompilerWarning = 0; | |
73 | wxASSERT(avoidCompilerWarning); // DBG:: item should be present | |
74 | ||
75 | return 0; | |
76 | } | |
77 | ||
78 | wxNode* GarbageCollector::FindReferenceFreeItemNode() | |
79 | { | |
80 | wxNode* pNode = mAllNodes.First(); | |
81 | ||
82 | while( pNode ) | |
83 | { | |
84 | if ( node_to_item( pNode ).mRefs.Number() == 0 ) | |
85 | ||
86 | return pNode; | |
87 | ||
88 | pNode = pNode->Next(); | |
89 | } | |
90 | ||
91 | return 0; | |
92 | } | |
93 | ||
94 | void GarbageCollector::RemoveReferencesToNode( wxNode* pItemNode ) | |
95 | { | |
96 | wxNode* pNode = mAllNodes.First(); | |
97 | ||
98 | while( pNode ) | |
99 | { | |
100 | wxList& refLst = node_to_item( pNode ).mRefs; | |
101 | wxNode* pRefNode = refLst.First(); | |
102 | ||
103 | while( pRefNode ) | |
104 | { | |
105 | if ( pRefNode->Data() == (wxObject*)pItemNode ) | |
106 | { | |
107 | wxNode* pNext = pRefNode->Next(); | |
108 | ||
109 | refLst.DeleteNode( pRefNode ); | |
110 | ||
111 | pRefNode = pNext; | |
112 | ||
113 | continue; | |
114 | } | |
115 | else pRefNode = pRefNode->Next(); | |
116 | } | |
117 | ||
118 | pNode = pNode->Next(); | |
119 | } | |
120 | } | |
121 | ||
122 | void GarbageCollector::ResolveReferences() | |
123 | { | |
124 | wxNode* pNode = mAllNodes.First(); | |
125 | ||
126 | while( pNode ) | |
127 | { | |
128 | GCItem& item = node_to_item( pNode ); | |
129 | ||
130 | wxNode* pRefNode = item.mRefs.First(); | |
131 | ||
132 | while( pRefNode ) | |
133 | { | |
134 | pRefNode->SetData( (wxObject*) FindItemNode( (void*)pRefNode->Data() ) ); | |
135 | ||
136 | pRefNode = pRefNode->Next(); | |
137 | } | |
138 | ||
139 | pNode = pNode->Next(); | |
140 | } | |
141 | } | |
142 | ||
143 | void GarbageCollector::AddObject( void* pObj, int refCnt ) | |
144 | { | |
145 | // FOR NOW:: initial ref-count is not used | |
146 | ||
147 | GCItem* pItem = new GCItem(); | |
148 | ||
149 | pItem->mpObj = pObj; | |
150 | ||
151 | mAllNodes.Append( (wxObject*) pItem ); | |
152 | } | |
153 | ||
154 | void GarbageCollector::AddDependency( void* pObj, void* pDependsOnObj ) | |
155 | { | |
156 | node_to_item( FindItemNode( pObj ) ).mRefs.Append( (wxObject*)pDependsOnObj ); | |
157 | } | |
158 | ||
159 | /*** GC alg. implementation ***/ | |
160 | ||
161 | void GarbageCollector::ArrangeCollection() | |
162 | { | |
163 | ResolveReferences(); | |
164 | ||
165 | do | |
166 | { | |
167 | // find node, which does not depend on anything | |
168 | ||
169 | wxNode* pItemNode = FindReferenceFreeItemNode(); | |
170 | ||
171 | if ( pItemNode ) | |
172 | { | |
173 | // append it to the list, where items are contained | |
174 | // in the increasing order of dependencies | |
175 | ||
176 | mRegularLst.Append( pItemNode->Data() ); | |
177 | ||
178 | mAllNodes.DeleteNode( pItemNode ); | |
179 | ||
180 | // remove references to this current "least-dependent" node | |
181 | // from reference lists of all the other nodes | |
182 | ||
183 | RemoveReferencesToNode( pItemNode ); | |
184 | } | |
185 | else | |
186 | { | |
187 | // otherwise, what is left - all nodes, which | |
188 | // are involved into cycled chains (rings) | |
189 | ||
190 | wxNode* pNode = mAllNodes.First(); | |
191 | ||
192 | while( pNode ) | |
193 | { | |
194 | mCycledLst.Append( pNode->Data() ); | |
195 | ||
196 | pNode = pNode->Next(); | |
197 | } | |
198 | ||
199 | break; | |
200 | } | |
201 | ||
202 | // continue search for "least-dependent" nodes | |
203 | ||
204 | } while(1); | |
205 | } | |
206 | ||
207 | wxList& GarbageCollector::GetRegularObjects() | |
208 | { | |
209 | return mRegularLst; | |
210 | } | |
211 | ||
212 | wxList& GarbageCollector::GetCycledObjects() | |
213 | { | |
214 | return mCycledLst; | |
215 | } | |
216 | ||
217 | void GarbageCollector::Reset() | |
218 | { | |
219 | DestroyItemList( mAllNodes ); | |
220 | ||
221 | mRegularLst.Clear(); | |
222 | mCycledLst.Clear(); | |
223 | } | |
224 |