1 /*
2 * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 package sun.jvm.hotspot.memory;
26
27 import java.io.*;
28 import java.util.*;
29 import sun.jvm.hotspot.debugger.*;
30 import sun.jvm.hotspot.oops.*;
31 import sun.jvm.hotspot.runtime.*;
32 import sun.jvm.hotspot.types.*;
33 import sun.jvm.hotspot.utilities.*;
34
35 public class CompactibleFreeListSpace extends CompactibleSpace {
36 private static AddressField collectorField;
37
38 // for free size, three fields
39 // FreeBlockDictionary* _dictionary; // ptr to dictionary for large size blocks
40 // FreeList _indexedFreeList[IndexSetSize]; // indexed array for small size blocks
41 // LinearAllocBlock _smallLinearAllocBlock; // small linear alloc in TLAB
42 private static AddressField indexedFreeListField;
43 private static AddressField dictionaryField;
44 private static long smallLinearAllocBlockFieldOffset;
45 private static long indexedFreeListSizeOf;
46
47 private int heapWordSize; // 4 for 32bit, 8 for 64 bits
48 private int IndexSetStart; // for small indexed list
49 private int IndexSetSize;
50 private int IndexSetStride;
51
52 static {
53 VM.registerVMInitializedObserver(new Observer() {
54 public void update(Observable o, Object data) {
55 initialize(VM.getVM().getTypeDataBase());
56 }
57 });
58 }
59
60 private static synchronized void initialize(TypeDataBase db) {
61 long sizeofFreeChunk = db.lookupType("FreeChunk").getSize();
62 VM vm = VM.getVM();
63 MinChunkSizeInBytes = numQuanta(sizeofFreeChunk, vm.getMinObjAlignmentInBytes()) *
64 vm.getMinObjAlignmentInBytes();
65
66 Type type = db.lookupType("CompactibleFreeListSpace");
67 collectorField = type.getAddressField("_collector");
68 collectorField = type.getAddressField("_collector");
69 dictionaryField = type.getAddressField("_dictionary");
70 indexedFreeListField = type.getAddressField("_indexedFreeList[0]");
71 smallLinearAllocBlockFieldOffset = type.getField("_smallLinearAllocBlock").getOffset();
72 }
73
74 public CompactibleFreeListSpace(Address addr) {
75 super(addr);
76 VM vm = VM.getVM();
77 heapWordSize = vm.getHeapWordSize();
78 IndexSetStart = vm.getMinObjAlignmentInBytes() / heapWordSize;
79 IndexSetStride = IndexSetStart;
80 IndexSetSize = 257;
81 }
82
83 // Accessing block offset table
84 public CMSCollector collector() {
85 return (CMSCollector) VMObjectFactory.newObject(
86 CMSCollector.class,
87 collectorField.getValue(addr));
88 }
89
90 public long free0() {
91 return capacity() - used0();
92 }
93
94 public long used() {
95 return capacity() - free();
96 }
97
98 public long used0() {
99 List regions = getLiveRegions();
100 long usedSize = 0L;
101 for (Iterator itr = regions.iterator(); itr.hasNext();) {
102 MemRegion mr = (MemRegion) itr.next();
103 usedSize += mr.byteSize();
104 }
105 return usedSize;
106 }
107
108 public long free() {
109 // small chunks
110 long size = 0;
111 Address cur = addr.addOffsetTo( indexedFreeListField.getOffset() );
112 cur = cur.addOffsetTo(IndexSetStart*FreeList.sizeOf());
113 for (int i=IndexSetStart; i<IndexSetSize; i += IndexSetStride) {
114 FreeList freeList = (FreeList) VMObjectFactory.newObject(FreeList.class, cur);
115 size += i*freeList.count();
116 cur= cur.addOffsetTo(IndexSetStride*FreeList.sizeOf());
117 }
118
119 // large block
120 AFLBinaryTreeDictionary aflbd = (AFLBinaryTreeDictionary) VMObjectFactory.newObject(AFLBinaryTreeDictionary.class,
121 dictionaryField.getValue(addr));
122 size += aflbd.size();
123
124
125 // linear block in TLAB
126 LinearAllocBlock lab = (LinearAllocBlock) VMObjectFactory.newObject(LinearAllocBlock.class,
127 addr.addOffsetTo(smallLinearAllocBlockFieldOffset));
128 size += lab.word_size();
129
130 return size*heapWordSize;
131 }
132
133 public void printOn(PrintStream tty) {
134 tty.print("free-list-space");
135 tty.print("[ " + bottom() + " , " + end() + " ) ");
136 long cap = capacity();
137 long used_size = used();
138 long free_size = free();
139 int used_perc = (int)((double)used_size/cap*100);
140 tty.print("space capacity = " + cap + " used(" + used_perc + "%)= " + used_size + " ");
141 tty.print("free= " + free_size );
142 tty.print("\n");
143
144 }
145
146 public Address skipBlockSizeUsingPrintezisBits(Address pos) {
147 CMSCollector collector = collector();
148 long size = 0;
149 Address addr = null;
150
151 if (collector != null) {
152 size = collector.blockSizeUsingPrintezisBits(pos);
153 if (size >= 3) {
154 addr = pos.addOffsetTo(adjustObjectSizeInBytes(size));
155 }
156 }
157 return addr;
158 }
159
160 public List/*<MemRegion>*/ getLiveRegions() {
161 List res = new ArrayList(); // List<MemRegion>
162 VM vm = VM.getVM();
163 Debugger dbg = vm.getDebugger();
164 ObjectHeap heap = vm.getObjectHeap();
165 Address cur = bottom();
166 Address regionStart = cur;
167 Address limit = end();
168 final long addressSize = vm.getAddressSize();
169
170 for (; cur.lessThan(limit);) {
171 Address k = cur.getAddressAt(addressSize);
172 if (FreeChunk.indicatesFreeChunk(cur)) {
173 if (! cur.equals(regionStart)) {
174 res.add(new MemRegion(regionStart, cur));
175 }
176 FreeChunk fc = (FreeChunk) VMObjectFactory.newObject(FreeChunk.class, cur);
177 long chunkSize = fc.size();
178 if (Assert.ASSERTS_ENABLED) {
179 Assert.that(chunkSize > 0, "invalid FreeChunk size");
180 }
181 // note that fc.size() gives chunk size in heap words
182 cur = cur.addOffsetTo(chunkSize * addressSize);
183 regionStart = cur;
184 } else if (k != null) {
185 Oop obj = heap.newOop(cur.addOffsetToAsOopHandle(0));
186 long objectSize = obj.getObjectSize();
187 cur = cur.addOffsetTo(adjustObjectSizeInBytes(objectSize));
188 } else {
189 // FIXME: need to do a better job here.
190 // can I use bitMap here?
191 //Find the object size using Printezis bits and skip over
192 long size = collector().blockSizeUsingPrintezisBits(cur);
193 if (size == -1) {
194 break;
195 }
196 cur = cur.addOffsetTo(adjustObjectSizeInBytes(size));
197 }
198 }
199 return res;
200 }
201
202 //-- Internals only below this point
203
204 // Unlike corresponding VM code, we operate on byte size rather than
205 // HeapWord size for convenience.
206
207 private static long numQuanta(long x, long y) {
208 return ((x+y-1)/y);
209 }
210
211 public static long adjustObjectSizeInBytes(long sizeInBytes) {
212 return Oop.alignObjectSize(Math.max(sizeInBytes, MinChunkSizeInBytes));
213 }
214
215 // FIXME: should I read this directly from VM?
216 private static long MinChunkSizeInBytes;
217 }