agent/src/share/classes/sun/jvm/hotspot/memory/SystemDictionary.java

rev 2 : [mq]: wkk.patch

@@ -27,25 +27,31 @@
 import java.util.*;
 import sun.jvm.hotspot.debugger.*;
 import sun.jvm.hotspot.oops.*;
 import sun.jvm.hotspot.runtime.*;
 import sun.jvm.hotspot.types.*;
+import sun.jvm.hotspot.types.OopField; // resolve ambiguity with oops.OopField
 
+// following needed for on-the-fly field construction:
+import sun.jvm.hotspot.types.basic.BasicOopField;
+import sun.jvm.hotspot.types.basic.BasicTypeDataBase;
+
 public class SystemDictionary {
   private static AddressField dictionaryField;
   private static AddressField sharedDictionaryField;
   private static AddressField placeholdersField;
   private static AddressField loaderConstraintTableField;
-  private static sun.jvm.hotspot.types.OopField javaSystemLoaderField;
+  private static OopField javaSystemLoaderField;
   private static int nofBuckets;
 
-  private static sun.jvm.hotspot.types.OopField objectKlassField;
-  private static sun.jvm.hotspot.types.OopField classLoaderKlassField;
-  private static sun.jvm.hotspot.types.OopField stringKlassField;
-  private static sun.jvm.hotspot.types.OopField systemKlassField;
-  private static sun.jvm.hotspot.types.OopField threadKlassField;
-  private static sun.jvm.hotspot.types.OopField threadGroupKlassField;
+  private static OopField wellKnownKlasses;
+  private static OopField objectKlassField;
+  private static OopField classLoaderKlassField;
+  private static OopField stringKlassField;
+  private static OopField systemKlassField;
+  private static OopField threadKlassField;
+  private static OopField threadGroupKlassField;
 
   static {
     VM.registerVMInitializedObserver(new Observer() {
         public void update(Observable o, Object data) {
           initialize(VM.getVM().getTypeDataBase());

@@ -61,18 +67,26 @@
     placeholdersField = type.getAddressField("_placeholders");
     loaderConstraintTableField = type.getAddressField("_loader_constraints");
     javaSystemLoaderField = type.getOopField("_java_system_loader");
     nofBuckets = db.lookupIntConstant("SystemDictionary::_nof_buckets").intValue();
 
-    objectKlassField = type.getOopField("_object_klass");
-    classLoaderKlassField = type.getOopField("_classloader_klass");
-    stringKlassField = type.getOopField("_string_klass");
-    systemKlassField = type.getOopField("_system_klass");
-    threadKlassField = type.getOopField("_thread_klass");
-    threadGroupKlassField = type.getOopField("_threadGroup_klass");
+    wellKnownKlasses = type.getOopField("_well_known_klasses[0]");
+    objectKlassField = findWellKnownKlass("object_klass", type, db);
+    classLoaderKlassField = findWellKnownKlass("classloader_klass", type, db);
+    stringKlassField = findWellKnownKlass("string_klass", type, db);
+    systemKlassField = findWellKnownKlass("system_klass", type, db);
+    threadKlassField = findWellKnownKlass("thread_klass", type, db);
+    threadGroupKlassField = findWellKnownKlass("threadGroup_klass", type, db);
   }
 
+  private static OopField findWellKnownKlass(String indexName, Type type, TypeDataBase db) {
+    Address wkk = wellKnownKlasses.getStaticFieldAddress();
+    int index = db.lookupIntConstant("SystemDictionary::#"+indexName).intValue();
+    return new BasicOopField((BasicTypeDataBase)db, type, indexName, type,
+                             true, index * db.getAddressSize(), wkk);
+  }
+
   public Dictionary dictionary() {
     Address tmp = dictionaryField.getValue();
     return (Dictionary) VMObjectFactory.newObject(Dictionary.class, tmp);
   }