8057536: Refactor G1 to allow context specific allocations

Summary: Splitting out a g1 allocator class to simply specialized allocators which can associate each allocation with a given context.
Reviewed-by: mgerdin, brutisso

2 files changed, 49 insertions, 5 deletions

diff --git a/agent/src/share/classes/sun/jvm/hotspot/gc_implementation/g1/G1Allocator.java b/agent/src/share/classes/sun/jvm/hotspot/gc_implementation/g1/G1Allocator.java
new file mode 100644
index 000000000..1195eed06
--- /dev/null
+++ b/agent/src/share/classes/sun/jvm/hotspot/gc_implementation/g1/G1Allocator.java
@@ -0,0 +1,40 @@
+package sun.jvm.hotspot.gc_implementation.g1;
+
+import java.util.Observable;
+import java.util.Observer;
+
+import sun.jvm.hotspot.debugger.Address;
+import sun.jvm.hotspot.runtime.VM;
+import sun.jvm.hotspot.runtime.VMObject;
+import sun.jvm.hotspot.types.CIntegerField;
+import sun.jvm.hotspot.types.Type;
+import sun.jvm.hotspot.types.TypeDataBase;
+
+public class G1Allocator extends VMObject {
+
+  //size_t _summary_bytes_used;
+  static private CIntegerField summaryBytesUsedField;
+
+  static {
+    VM.registerVMInitializedObserver(new Observer() {
+      public void update(Observable o, Object data) {
+        initialize(VM.getVM().getTypeDataBase());
+      }
+    });
+  }
+
+  static private synchronized void initialize(TypeDataBase db) {
+    Type type = db.lookupType("G1Allocator");
+
+    summaryBytesUsedField = type.getCIntegerField("_summary_bytes_used");
+  }
+
+  public long getSummaryBytes() {
+    return summaryBytesUsedField.getValue(addr);
+  }
+
+  public G1Allocator(Address addr) {
+    super(addr);
+
+  }
+}
diff --git a/agent/src/share/classes/sun/jvm/hotspot/gc_implementation/g1/G1CollectedHeap.java b/agent/src/share/classes/sun/jvm/hotspot/gc_implementation/g1/G1CollectedHeap.java
index e177468e5..b0b6d8462 100644
--- a/agent/src/share/classes/sun/jvm/hotspot/gc_implementation/g1/G1CollectedHeap.java
+++ b/agent/src/share/classes/sun/jvm/hotspot/gc_implementation/g1/G1CollectedHeap.java
@@ -36,7 +36,6 @@ import sun.jvm.hotspot.memory.SpaceClosure;
 import sun.jvm.hotspot.runtime.VM;
 import sun.jvm.hotspot.runtime.VMObjectFactory;
 import sun.jvm.hotspot.types.AddressField;
-import sun.jvm.hotspot.types.CIntegerField;
 import sun.jvm.hotspot.types.Type;
 import sun.jvm.hotspot.types.TypeDataBase;
 
@@ -47,8 +46,8 @@ public class G1CollectedHeap extends SharedHeap {
     static private long hrmFieldOffset;
     // MemRegion _g1_reserved;
     static private long g1ReservedFieldOffset;
-    // size_t _summary_bytes_used;
-    static private CIntegerField summaryBytesUsedField;
+    // G1Allocator* _allocator
+    static private AddressField g1Allocator;
     // G1MonitoringSupport* _g1mm;
     static private AddressField g1mmField;
     // HeapRegionSet _old_set;
@@ -68,7 +67,7 @@ public class G1CollectedHeap extends SharedHeap {
         Type type = db.lookupType("G1CollectedHeap");
 
         hrmFieldOffset = type.getField("_hrm").getOffset();
-        summaryBytesUsedField = type.getCIntegerField("_summary_bytes_used");
+        g1Allocator = type.getAddressField("_allocator");
         g1mmField = type.getAddressField("_g1mm");
         oldSetFieldOffset = type.getField("_old_set").getOffset();
         humongousSetFieldOffset = type.getField("_humongous_set").getOffset();
@@ -79,7 +78,7 @@ public class G1CollectedHeap extends SharedHeap {
     }
 
     public long used() {
-        return summaryBytesUsedField.getValue(addr);
+        return allocator().getSummaryBytes();
     }
 
     public long n_regions() {
@@ -97,6 +96,11 @@ public class G1CollectedHeap extends SharedHeap {
         return (G1MonitoringSupport) VMObjectFactory.newObject(G1MonitoringSupport.class, g1mmAddr);
     }
 
+    public G1Allocator allocator() {
+        Address g1AllocatorAddr = g1Allocator.getValue(addr);
+        return (G1Allocator) VMObjectFactory.newObject(G1Allocator.class, g1AllocatorAddr);
+    }
+
     public HeapRegionSetBase oldSet() {
         Address oldSetAddr = addr.addOffsetTo(oldSetFieldOffset);
         return (HeapRegionSetBase) VMObjectFactory.newObject(HeapRegionSetBase.class,