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