[277422] Switch ClassImpl to use atomic instructions rather than synchronized block

Change-Id: I5e35bb0f7a59bc041e67e28a8cec56f1ee010eae
Signed-off-by: Jason Koch <jkoch@netflix.com>

1 files changed, 11 insertions, 6 deletions

diff --git a/plugins/org.eclipse.mat.parser/src/org/eclipse/mat/parser/model/ClassImpl.java b/plugins/org.eclipse.mat.parser/src/org/eclipse/mat/parser/model/ClassImpl.java
index 41ab6573..735c63d4 100644
--- a/plugins/org.eclipse.mat.parser/src/org/eclipse/mat/parser/model/ClassImpl.java
+++ b/plugins/org.eclipse.mat.parser/src/org/eclipse/mat/parser/model/ClassImpl.java
@@ -18,6 +18,8 @@ import java.util.Arrays;
 import java.util.Collections;

 import java.util.LinkedList;

 import java.util.List;

+import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;

+import java.util.concurrent.atomic.AtomicLongFieldUpdater;

 

 import org.eclipse.mat.SnapshotException;

 import org.eclipse.mat.collect.ArrayInt;

@@ -41,6 +43,10 @@ import org.eclipse.mat.util.VoidProgressListener;
 public class ClassImpl extends AbstractObjectImpl implements IClass, Comparable<ClassImpl>

 {

     private static final long serialVersionUID = 22L;

+    private static final transient AtomicIntegerFieldUpdater<ClassImpl> instanceCountUpdater =

+                    AtomicIntegerFieldUpdater.newUpdater(ClassImpl.class, "instanceCount");

+    private static final transient AtomicLongFieldUpdater<ClassImpl> totalSizeUpdater =

+                    AtomicLongFieldUpdater.newUpdater(ClassImpl.class, "totalSize");

 

     public static final String JAVA_LANG_CLASS = IClass.JAVA_LANG_CLASS;

 

@@ -53,8 +59,8 @@ public class ClassImpl extends AbstractObjectImpl implements IClass, Comparable<
     protected FieldDescriptor[] fields;

     protected int usedHeapSize;

     protected int instanceSize;

-    protected int instanceCount;

-    protected long totalSize;

+    protected volatile int instanceCount;

+    protected volatile long totalSize;

     protected boolean isArrayType;

 

     private List<IClass> subClasses;

@@ -323,11 +329,10 @@ public class ClassImpl extends AbstractObjectImpl implements IClass, Comparable<
     /**

 	 * @since 1.0

 	 */

-    public synchronized void addInstance(long usedHeapSize)

+    public void addInstance(long usedHeapSize)

     {

-        // TODO this could be converted to atomic field updaters

-        this.instanceCount++;

-        this.totalSize += usedHeapSize;

+        instanceCountUpdater.getAndAdd(this, 1);

+        totalSizeUpdater.getAndAdd(this, usedHeapSize);

     }

 

     /**