diff agent/src/share/classes/sun/jvm/hotspot/memory/Universe.java @ 642:660978a2a31a

6791178: Specialize for zero as the compressed oop vm heap base Summary: Use zero based compressed oops if java heap is below 32gb and unscaled compressed oops if java heap is below 4gb. Reviewed-by: never, twisti, jcoomes, coleenp
author kvn
date Thu, 12 Mar 2009 10:37:46 -0700
parents d1605aabd0a1
children bd02caa94611
line wrap: on
line diff
--- a/agent/src/share/classes/sun/jvm/hotspot/memory/Universe.java	Wed Mar 11 14:16:13 2009 -0700
+++ b/agent/src/share/classes/sun/jvm/hotspot/memory/Universe.java	Thu Mar 12 10:37:46 2009 -0700
@@ -53,7 +53,8 @@
   // system obj array klass object
   private static sun.jvm.hotspot.types.OopField systemObjArrayKlassObjField;
 
-  private static AddressField heapBaseField;
+  private static AddressField narrowOopBaseField;
+  private static CIntegerField narrowOopShiftField;
 
   static {
     VM.registerVMInitializedObserver(new Observer() {
@@ -86,7 +87,8 @@
 
     systemObjArrayKlassObjField = type.getOopField("_systemObjArrayKlassObj");
 
-    heapBaseField = type.getAddressField("_heap_base");
+    narrowOopBaseField = type.getAddressField("_narrow_oop._base");
+    narrowOopShiftField = type.getCIntegerField("_narrow_oop._shift");
   }
 
   public Universe() {
@@ -100,14 +102,18 @@
     }
   }
 
-  public static long getHeapBase() {
-    if (heapBaseField.getValue() == null) {
+  public static long getNarrowOopBase() {
+    if (narrowOopBaseField.getValue() == null) {
       return 0;
     } else {
-      return heapBaseField.getValue().minus(null);
+      return narrowOopBaseField.getValue().minus(null);
     }
   }
 
+  public static int getNarrowOopShift() {
+    return (int)narrowOopShiftField.getValue();
+  }
+
   /** Returns "TRUE" iff "p" points into the allocated area of the heap. */
   public boolean isIn(Address p) {
     return heap().isIn(p);