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 }