1 /*
2 * Copyright (c) 2000, 2012, 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.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("AdapterBlob", AdapterBlob.class);
61 virtualConstructor.addMapping("MethodHandlesAdapterBlob", MethodHandlesAdapterBlob.class);
62 virtualConstructor.addMapping("SafepointBlob", SafepointBlob.class);
63 virtualConstructor.addMapping("DeoptimizationBlob", DeoptimizationBlob.class);
64 if (VM.getVM().isServerCompiler()) {
65 virtualConstructor.addMapping("ExceptionBlob", ExceptionBlob.class);
66 virtualConstructor.addMapping("UncommonTrapBlob", UncommonTrapBlob.class);
67 }
68 }
69
70 public CodeCache() {
71 heap = (CodeHeap) VMObjectFactory.newObject(CodeHeap.class, heapField.getValue());
72 }
73
74 public NMethod scavengeRootMethods() {
75 return (NMethod) VMObjectFactory.newObject(NMethod.class, scavengeRootNMethodsField.getValue());
76 }
77
78 public boolean contains(Address p) {
79 return getHeap().contains(p);
80 }
81
82 /** When VM.getVM().isDebugging() returns true, this behaves like
83 findBlobUnsafe */
84 public CodeBlob findBlob(Address start) {
85 CodeBlob result = findBlobUnsafe(start);
86 if (result == null) return null;
87 if (VM.getVM().isDebugging()) {
88 return result;
89 }
90 // We could potientially look up non_entrant methods
91 // NOTE: this is effectively a "guarantee", and is slightly different from the one in the VM
92 if (Assert.ASSERTS_ENABLED) {
93 Assert.that(!(result.isZombie() || result.isLockedByVM()), "unsafe access to zombie method");
94 }
95 return result;
96 }
97
98 public CodeBlob findBlobUnsafe(Address start) {
99 CodeBlob result = null;
100
101 try {
102 result = (CodeBlob) virtualConstructor.instantiateWrapperFor(getHeap().findStart(start));
103 }
104 catch (WrongTypeException wte) {
105 Address cbAddr = null;
106 try {
107 cbAddr = getHeap().findStart(start);
108 }
109 catch (Exception findEx) {
110 findEx.printStackTrace();
111 }
112
113 String message = "Couldn't deduce type of CodeBlob ";
114 if (cbAddr != null) {
115 message = message + "@" + cbAddr + " ";
116 }
117 message = message + "for PC=" + start;
118
119 throw new RuntimeException(message, wte);
120 }
121 if (result == null) return null;
122 if (Assert.ASSERTS_ENABLED) {
123 // The HeapBlock that contains this blob is outside of the blob
124 // but it shouldn't be an error to find a blob based on the
125 // pointer to the HeapBlock.
126 Assert.that(result.blobContains(start) || result.blobContains(start.addOffsetTo(8)),
127 "found wrong CodeBlob");
128 }
129 return result;
130 }
131
132 public NMethod findNMethod(Address start) {
133 CodeBlob cb = findBlob(start);
134 if (Assert.ASSERTS_ENABLED) {
135 Assert.that(cb == null || cb.isNMethod(), "did not find an nmethod");
136 }
137 return (NMethod) cb;
138 }
139
140 public NMethod findNMethodUnsafe(Address start) {
141 CodeBlob cb = findBlobUnsafe(start);
142 if (Assert.ASSERTS_ENABLED) {
143 Assert.that(cb == null || cb.isNMethod(), "did not find an nmethod");
144 }
145 return (NMethod) cb;
146 }
147
148 /** Routine for instantiating appropriately-typed wrapper for a
149 CodeBlob. Used by CodeCache, Runtime1, etc. */
150 public CodeBlob createCodeBlobWrapper(Address codeBlobAddr) {
151 try {
152 return (CodeBlob) virtualConstructor.instantiateWrapperFor(codeBlobAddr);
153 }
154 catch (Exception e) {
155 String message = "Unable to deduce type of CodeBlob from address " + codeBlobAddr +
156 " (expected type nmethod, RuntimeStub, ";
157 if (VM.getVM().isClientCompiler()) {
158 message = message + " or ";
159 }
160 message = message + "SafepointBlob";
161 if (VM.getVM().isServerCompiler()) {
162 message = message + ", DeoptimizationBlob, or ExceptionBlob";
163 }
164 message = message + ")";
165 throw new RuntimeException(message);
166 }
167 }
168
169 public void iterate(CodeCacheVisitor visitor) {
170 CodeHeap heap = getHeap();
171 Address ptr = heap.begin();
172 Address end = heap.end();
173
174 visitor.prologue(ptr, end);
175 CodeBlob lastBlob = null;
176 while (ptr != null && ptr.lessThan(end)) {
177 try {
178 // Use findStart to get a pointer inside blob other findBlob asserts
179 CodeBlob blob = findBlobUnsafe(heap.findStart(ptr));
180 if (blob != null) {
181 visitor.visit(blob);
182 if (blob == lastBlob) {
183 throw new InternalError("saw same blob twice");
184 }
185 lastBlob = blob;
186 }
187 } catch (RuntimeException e) {
188 e.printStackTrace();
189 }
190 Address next = heap.nextBlock(ptr);
191 if (next != null && next.lessThan(ptr)) {
192 throw new InternalError("pointer moved backwards");
193 }
194 ptr = next;
195 }
196 visitor.epilogue();
197 }
198
199 //--------------------------------------------------------------------------------
200 // Internals only below this point
201 //
202
203 private CodeHeap getHeap() {
204 return heap;
205 }
206 }