1 /*
2 * Copyright 2000-2005 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
24
25 package sun.jvm.hotspot.code;
26
27 import java.util.*;
28 import sun.jvm.hotspot.debugger.*;
29 import sun.jvm.hotspot.memory.*;
30 import sun.jvm.hotspot.runtime.*;
31 import sun.jvm.hotspot.types.*;
32 import sun.jvm.hotspot.utilities.*;
33
34 public class CodeCache {
35 private static AddressField heapField;
36 private static AddressField scavengeRootNMethodsField;
37 private static VirtualConstructor virtualConstructor;
38
39 private CodeHeap heap;
40
41 static {
42 VM.registerVMInitializedObserver(new Observer() {
43 public void update(Observable o, Object data) {
44 initialize(VM.getVM().getTypeDataBase());
45 }
46 });
47 }
48
49 private static synchronized void initialize(TypeDataBase db) {
50 Type type = db.lookupType("CodeCache");
51
52 heapField = type.getAddressField("_heap");
53 scavengeRootNMethodsField = type.getAddressField("_scavenge_root_nmethods");
54
55 virtualConstructor = new VirtualConstructor(db);
56 // Add mappings for all possible CodeBlob subclasses
57 virtualConstructor.addMapping("BufferBlob", BufferBlob.class);
58 virtualConstructor.addMapping("nmethod", NMethod.class);
59 virtualConstructor.addMapping("RuntimeStub", RuntimeStub.class);
60 virtualConstructor.addMapping("SafepointBlob", SafepointBlob.class);
61 virtualConstructor.addMapping("DeoptimizationBlob", DeoptimizationBlob.class);
62 if (VM.getVM().isServerCompiler()) {
63 virtualConstructor.addMapping("ExceptionBlob", ExceptionBlob.class);
64 virtualConstructor.addMapping("UncommonTrapBlob", UncommonTrapBlob.class);
65 }
66 }
67
68 public CodeCache() {
69 heap = (CodeHeap) VMObjectFactory.newObject(CodeHeap.class, heapField.getValue());
70 }
71
72 public NMethod scavengeRootMethods() {
73 return (NMethod) VMObjectFactory.newObject(NMethod.class, scavengeRootNMethodsField.getValue());
74 }
75
76 public boolean contains(Address p) {
77 return getHeap().contains(p);
78 }
79
80 /** When VM.getVM().isDebugging() returns true, this behaves like
81 findBlobUnsafe */
82 public CodeBlob findBlob(Address start) {
83 CodeBlob result = findBlobUnsafe(start);
84 if (result == null) return null;
85 if (VM.getVM().isDebugging()) {
86 return result;
87 }
88 // We could potientially look up non_entrant methods
89 // NOTE: this is effectively a "guarantee", and is slightly different from the one in the VM
90 if (Assert.ASSERTS_ENABLED) {
91 Assert.that(!(result.isZombie() || result.isLockedByVM()), "unsafe access to zombie method");
92 }
93 return result;
94 }
95
96 public CodeBlob findBlobUnsafe(Address start) {
97 CodeBlob result = null;
98
99 try {
100 result = (CodeBlob) virtualConstructor.instantiateWrapperFor(getHeap().findStart(start));
101 }
102 catch (WrongTypeException wte) {
103 Address cbAddr = null;
104 try {
105 cbAddr = getHeap().findStart(start);
106 }
107 catch (Exception findEx) {
108 findEx.printStackTrace();
109 }
110
111 String message = "Couldn't deduce type of CodeBlob ";
112 if (cbAddr != null) {
113 message = message + "@" + cbAddr + " ";
114 }
115 message = message + "for PC=" + start;
116
117 throw new RuntimeException(message, wte);
118 }
119 if (result == null) return null;
120 if (Assert.ASSERTS_ENABLED) {
121 // The HeapBlock that contains this blob is outside of the blob
122 // but it shouldn't be an error to find a blob based on the
123 // pointer to the HeapBlock.
124 Assert.that(result.blobContains(start) || result.blobContains(start.addOffsetTo(8)),
125 "found wrong CodeBlob");
126 }
127 return result;
128 }
129
130 public NMethod findNMethod(Address start) {
131 CodeBlob cb = findBlob(start);
132 if (Assert.ASSERTS_ENABLED) {
133 Assert.that(cb == null || cb.isNMethod(), "did not find an nmethod");
134 }
135 return (NMethod) cb;
136 }
137
138 public NMethod findNMethodUnsafe(Address start) {
139 CodeBlob cb = findBlobUnsafe(start);
140 if (Assert.ASSERTS_ENABLED) {
141 Assert.that(cb == null || cb.isNMethod(), "did not find an nmethod");
142 }
143 return (NMethod) cb;
144 }
145
146 /** Routine for instantiating appropriately-typed wrapper for a
147 CodeBlob. Used by CodeCache, Runtime1, etc. */
148 public CodeBlob createCodeBlobWrapper(Address codeBlobAddr) {
149 try {
150 return (CodeBlob) virtualConstructor.instantiateWrapperFor(codeBlobAddr);
151 }
152 catch (Exception e) {
153 String message = "Unable to deduce type of CodeBlob from address " + codeBlobAddr +
154 " (expected type nmethod, RuntimeStub, ";
155 if (VM.getVM().isClientCompiler()) {
156 message = message + " or ";
157 }
158 message = message + "SafepointBlob";
159 if (VM.getVM().isServerCompiler()) {
160 message = message + ", DeoptimizationBlob, or ExceptionBlob";
161 }
162 message = message + ")";
163 throw new RuntimeException(message);
164 }
165 }
166
167 public void iterate(CodeCacheVisitor visitor) {
168 CodeHeap heap = getHeap();
169 Address ptr = heap.begin();
170 Address end = heap.end();
171
172 visitor.prologue(ptr, end);
173 CodeBlob lastBlob = null;
174 while (ptr != null && ptr.lessThan(end)) {
175 try {
176 // Use findStart to get a pointer inside blob other findBlob asserts
177 CodeBlob blob = findBlobUnsafe(heap.findStart(ptr));
178 if (blob != null) {
179 visitor.visit(blob);
180 if (blob == lastBlob) {
181 throw new InternalError("saw same blob twice");
182 }
183 lastBlob = blob;
184 }
185 } catch (RuntimeException e) {
186 e.printStackTrace();
187 }
188 Address next = heap.nextBlock(ptr);
189 if (next != null && next.lessThan(ptr)) {
190 throw new InternalError("pointer moved backwards");
191 }
192 ptr = next;
193 }
194 visitor.epilogue();
195 }
196
197 //--------------------------------------------------------------------------------
198 // Internals only below this point
199 //
200
201 private CodeHeap getHeap() {
202 return heap;
203 }
204 }