1 /* 2 * Copyright (c) 2000, 2011, 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.oops; 26 27 import java.util.*; 28 29 import sun.jvm.hotspot.debugger.*; 30 import sun.jvm.hotspot.memory.*; 31 import sun.jvm.hotspot.runtime.*; 32 import sun.jvm.hotspot.types.TypeDataBase; 33 import sun.jvm.hotspot.utilities.*; 34 import sun.jvm.hotspot.jdi.JVMTIThreadState; 35 36 /** A utility class encapsulating useful oop operations */ 37 38 public class OopUtilities implements /* imports */ JVMTIThreadState { 39 40 // FIXME: access should be synchronized and cleared when VM is 41 // resumed 42 // String fields 43 private static IntField offsetField; 44 private static IntField countField; 45 private static OopField valueField; 46 // ThreadGroup fields 47 private static OopField threadGroupParentField; 48 private static OopField threadGroupNameField; 49 private static IntField threadGroupNThreadsField; 50 private static OopField threadGroupThreadsField; 51 private static IntField threadGroupNGroupsField; 52 private static OopField threadGroupGroupsField; 53 // Thread fields 54 private static OopField threadNameField; 55 private static OopField threadGroupField; 56 private static LongField threadEETopField; 57 // threadStatus field is new since 1.5 58 private static IntField threadStatusField; 59 // parkBlocker field is new since 1.6 60 private static OopField threadParkBlockerField; 61 62 // possible values of java_lang_Thread::ThreadStatus 63 private static int THREAD_STATUS_NEW; 64 /* 65 Other enum constants are not needed as of now. Uncomment these as and when needed. 66 67 private static int THREAD_STATUS_RUNNABLE; 68 private static int THREAD_STATUS_SLEEPING; 69 private static int THREAD_STATUS_IN_OBJECT_WAIT; 70 private static int THREAD_STATUS_IN_OBJECT_WAIT_TIMED; 71 private static int THREAD_STATUS_PARKED; 72 private static int THREAD_STATUS_PARKED_TIMED; 73 private static int THREAD_STATUS_BLOCKED_ON_MONITOR_ENTER; 74 private static int THREAD_STATUS_TERMINATED; 75 */ 76 77 // java.util.concurrent.locks.AbstractOwnableSynchronizer fields 78 private static OopField absOwnSyncOwnerThreadField; 79 80 static { 81 VM.registerVMInitializedObserver(new Observer() { 82 public void update(Observable o, Object data) { 83 initialize(VM.getVM().getTypeDataBase()); 84 } 85 }); 86 } 87 88 private static synchronized void initialize(TypeDataBase db) { 89 // FIXME: don't need this observer; however, do need a VM resumed 90 // and suspended observer to refetch fields 91 } 92 93 public static String charArrayToString(TypeArray charArray) { 94 if (charArray == null) { 95 return null; 96 } 97 return charArrayToString(charArray, 0, (int) charArray.getLength()); 98 } 99 100 public static String charArrayToString(TypeArray charArray, int offset, int length) { 101 if (charArray == null) { 102 return null; 103 } 104 final int limit = offset + length; 105 if (Assert.ASSERTS_ENABLED) { 106 Assert.that(offset >= 0 && limit <= charArray.getLength(), "out of bounds"); 107 } 108 StringBuffer buf = new StringBuffer(length); 109 for (int i = offset; i < limit; i++) { 110 buf.append(charArray.getCharAt(i)); 111 } 112 return buf.toString(); 113 } 114 115 public static String escapeString(String s) { 116 StringBuilder sb = null; 117 for (int index = 0; index < s.length(); index++) { 118 char value = s.charAt(index); 119 if (value >= 32 && value < 127 || value == '\'' || value == '\\') { 120 if (sb != null) { 121 sb.append(value); 122 } 123 } else { 124 if (sb == null) { 125 sb = new StringBuilder(s.length() * 2); 126 sb.append(s, 0, index); 127 } 128 sb.append("\\u"); 129 if (value < 0x10) sb.append("000"); 130 else if (value < 0x100) sb.append("00"); 131 else if (value < 0x1000) sb.append("0"); 132 sb.append(Integer.toHexString(value)); 133 } 134 } 135 if (sb != null) { 136 return sb.toString(); 137 } 138 return s; 139 } 140 141 public static String stringOopToString(Oop stringOop) { 142 if (offsetField == null) { 143 InstanceKlass k = (InstanceKlass) stringOop.getKlass(); 144 offsetField = (IntField) k.findField("offset", "I"); 145 countField = (IntField) k.findField("count", "I"); 146 valueField = (OopField) k.findField("value", "[C"); 147 if (Assert.ASSERTS_ENABLED) { 148 Assert.that(offsetField != null && 149 countField != null && 150 valueField != null, "must find all java.lang.String fields"); 151 } 152 } 153 return charArrayToString((TypeArray) valueField.getValue(stringOop), 154 offsetField.getValue(stringOop), 155 countField.getValue(stringOop)); 156 } 157 158 public static String stringOopToEscapedString(Oop stringOop) { 159 return escapeString(stringOopToString(stringOop)); 160 } 161 162 private static void initThreadGroupFields() { 163 if (threadGroupParentField == null) { 164 SystemDictionary sysDict = VM.getVM().getSystemDictionary(); 165 InstanceKlass k = sysDict.getThreadGroupKlass(); 166 threadGroupParentField = (OopField) k.findField("parent", "Ljava/lang/ThreadGroup;"); 167 threadGroupNameField = (OopField) k.findField("name", "Ljava/lang/String;"); 168 threadGroupNThreadsField = (IntField) k.findField("nthreads", "I"); 169 threadGroupThreadsField = (OopField) k.findField("threads", "[Ljava/lang/Thread;"); 170 threadGroupNGroupsField = (IntField) k.findField("ngroups", "I"); 171 threadGroupGroupsField = (OopField) k.findField("groups", "[Ljava/lang/ThreadGroup;"); 172 if (Assert.ASSERTS_ENABLED) { 173 Assert.that(threadGroupParentField != null && 174 threadGroupNameField != null && 175 threadGroupNThreadsField != null && 176 threadGroupThreadsField != null && 177 threadGroupNGroupsField != null && 178 threadGroupGroupsField != null, "must find all java.lang.ThreadGroup fields"); 179 } 180 } 181 } 182 183 public static Oop threadGroupOopGetParent(Oop threadGroupOop) { 184 initThreadGroupFields(); 185 return threadGroupParentField.getValue(threadGroupOop); 186 } 187 188 public static String threadGroupOopGetName(Oop threadGroupOop) { 189 initThreadGroupFields(); 190 return stringOopToString(threadGroupNameField.getValue(threadGroupOop)); 191 } 192 193 public static Oop[] threadGroupOopGetThreads(Oop threadGroupOop) { 194 initThreadGroupFields(); 195 int nthreads = threadGroupNThreadsField.getValue(threadGroupOop); 196 Oop[] result = new Oop[nthreads]; 197 ObjArray threads = (ObjArray) threadGroupThreadsField.getValue(threadGroupOop); 198 for (int i = 0; i < nthreads; i++) { 199 result[i] = threads.getObjAt(i); 200 } 201 return result; 202 } 203 204 public static Oop[] threadGroupOopGetGroups(Oop threadGroupOop) { 205 initThreadGroupFields(); 206 int ngroups = threadGroupNGroupsField.getValue(threadGroupOop); 207 Oop[] result = new Oop[ngroups]; 208 ObjArray groups = (ObjArray) threadGroupGroupsField.getValue(threadGroupOop); 209 for (int i = 0; i < ngroups; i++) { 210 result[i] = groups.getObjAt(i); 211 } 212 return result; 213 } 214 215 private static void initThreadFields() { 216 if (threadNameField == null) { 217 SystemDictionary sysDict = VM.getVM().getSystemDictionary(); 218 InstanceKlass k = sysDict.getThreadKlass(); 219 threadNameField = (OopField) k.findField("name", "[C"); 220 threadGroupField = (OopField) k.findField("group", "Ljava/lang/ThreadGroup;"); 221 threadEETopField = (LongField) k.findField("eetop", "J"); 222 threadStatusField = (IntField) k.findField("threadStatus", "I"); 223 threadParkBlockerField = (OopField) k.findField("parkBlocker", 224 "Ljava/lang/Object;"); 225 TypeDataBase db = VM.getVM().getTypeDataBase(); 226 THREAD_STATUS_NEW = db.lookupIntConstant("java_lang_Thread::NEW").intValue(); 227 /* 228 Other enum constants are not needed as of now. Uncomment these as and when needed. 229 230 THREAD_STATUS_RUNNABLE = db.lookupIntConstant("java_lang_Thread::RUNNABLE").intValue(); 231 THREAD_STATUS_SLEEPING = db.lookupIntConstant("java_lang_Thread::SLEEPING").intValue(); 232 THREAD_STATUS_IN_OBJECT_WAIT = db.lookupIntConstant("java_lang_Thread::IN_OBJECT_WAIT").intValue(); 233 THREAD_STATUS_IN_OBJECT_WAIT_TIMED = db.lookupIntConstant("java_lang_Thread::IN_OBJECT_WAIT_TIMED").intValue(); 234 THREAD_STATUS_PARKED = db.lookupIntConstant("java_lang_Thread::PARKED").intValue(); 235 THREAD_STATUS_PARKED_TIMED = db.lookupIntConstant("java_lang_Thread::PARKED_TIMED").intValue(); 236 THREAD_STATUS_BLOCKED_ON_MONITOR_ENTER = db.lookupIntConstant("java_lang_Thread::BLOCKED_ON_MONITOR_ENTER").intValue(); 237 THREAD_STATUS_TERMINATED = db.lookupIntConstant("java_lang_Thread::TERMINATED").intValue(); 238 */ 239 240 if (Assert.ASSERTS_ENABLED) { 241 // it is okay to miss threadStatusField, because this was 242 // introduced only in 1.5 JDK. 243 Assert.that(threadNameField != null && 244 threadGroupField != null && 245 threadEETopField != null, "must find all java.lang.Thread fields"); 246 } 247 } 248 } 249 250 public static Oop threadOopGetThreadGroup(Oop threadOop) { 251 initThreadFields(); 252 return threadGroupField.getValue(threadOop); 253 } 254 255 public static String threadOopGetName(Oop threadOop) { 256 initThreadFields(); 257 return charArrayToString((TypeArray) threadNameField.getValue(threadOop)); 258 } 259 260 /** May return null if, e.g., thread was not started */ 261 public static JavaThread threadOopGetJavaThread(Oop threadOop) { 262 initThreadFields(); 263 Address addr = threadOop.getHandle().getAddressAt(threadEETopField.getOffset()); 264 if (addr == null) { 265 return null; 266 } 267 return VM.getVM().getThreads().createJavaThreadWrapper(addr); 268 } 269 270 /** returns value of java.lang.Thread.threadStatus field */ 271 public static int threadOopGetThreadStatus(Oop threadOop) { 272 initThreadFields(); 273 // The threadStatus is only present starting in 1.5 274 if (threadStatusField != null) { 275 return (int) threadStatusField.getValue(threadOop); 276 } else { 277 // All we can easily figure out is if it is alive, but that is 278 // enough info for a valid unknown status. 279 JavaThread thr = threadOopGetJavaThread(threadOop); 280 if (thr == null) { 281 // the thread hasn't run yet or is in the process of exiting 282 return THREAD_STATUS_NEW; 283 } else { 284 return JVMTI_THREAD_STATE_ALIVE; 285 } 286 } 287 } 288 289 /** returns value of java.lang.Thread.parkBlocker field */ 290 public static Oop threadOopGetParkBlocker(Oop threadOop) { 291 initThreadFields(); 292 if (threadParkBlockerField != null) { 293 return threadParkBlockerField.getValue(threadOop); 294 } 295 return null; 296 } 297 298 // initialize fields for j.u.c.l AbstractOwnableSynchornizer class 299 private static void initAbsOwnSyncFields() { 300 if (absOwnSyncOwnerThreadField == null) { 301 SystemDictionary sysDict = VM.getVM().getSystemDictionary(); 302 InstanceKlass k = sysDict.getAbstractOwnableSynchronizerKlass(); 303 absOwnSyncOwnerThreadField = 304 (OopField) k.findField("exclusiveOwnerThread", 305 "Ljava/lang/Thread;"); 306 } 307 } 308 309 // return exclusiveOwnerThread field of AbstractOwnableSynchronizer class 310 public static Oop abstractOwnableSynchronizerGetOwnerThread(Oop oop) { 311 initAbsOwnSyncFields(); 312 if (absOwnSyncOwnerThreadField == null) { 313 return null; // pre-1.6 VM? 314 } else { 315 return absOwnSyncOwnerThreadField.getValue(oop); 316 } 317 } 318 }