AMQ-7402: Inconsistent synchronization of getters/setters of some classes

Make synchronization consistent or remove it and declare the field volatile.

activemq-broker/src/main/java/org/apache/activemq/broker/region/TopicSubscription.java

@@ -504,7 +504,7 @@ public class TopicSubscription extends AbstractSubscription {
         this.messageEvictionStrategy = messageEvictionStrategy;
     }
 
-    public int getMaxProducersToAudit() {
+    public synchronized int getMaxProducersToAudit() {
         return maxProducersToAudit;
     }
 
@@ -515,7 +515,7 @@ public class TopicSubscription extends AbstractSubscription {
         }
     }
 
-    public int getMaxAuditDepth() {
+    public synchronized int getMaxAuditDepth() {
         return maxAuditDepth;
     }
 

activemq-broker/src/main/java/org/apache/activemq/broker/region/cursors/AbstractPendingMessageCursor.java

@@ -260,7 +260,7 @@ public abstract class AbstractPendingMessageCursor implements PendingMessageCurs
      * @return the maxProducersToAudit
      */
     @Override
-    public int getMaxProducersToAudit() {
+    public synchronized int getMaxProducersToAudit() {
         return maxProducersToAudit;
     }
 
@@ -279,7 +279,7 @@ public abstract class AbstractPendingMessageCursor implements PendingMessageCurs
      * @return the maxAuditDepth
      */
     @Override
-    public int getMaxAuditDepth() {
+    public synchronized int getMaxAuditDepth() {
         return maxAuditDepth;
     }
 

activemq-client/src/main/java/org/apache/activemq/management/SizeStatisticImpl.java

@@ -19,8 +19,8 @@ package org.apache.activemq.management;
 public class SizeStatisticImpl extends StatisticImpl {
 
     private long count;
-    private long maxSize;
-    private long minSize;
+    private volatile long maxSize;
+    private volatile long minSize;
     private long totalSize;
     private SizeStatisticImpl parent;
 
@@ -94,21 +94,21 @@ public class SizeStatisticImpl extends StatisticImpl {
     /**
      * @return the maximum size of any step
      */
-    public synchronized void setMaxSize(long size) {
+    public void setMaxSize(long size) {
         maxSize = size;
     }
 
     /**
      * @return the minimum size of any step
      */
-    public synchronized long getMinSize() {
+    public long getMinSize() {
         return minSize;
     }
 
     /**
      * @return the maximum size of any step
      */
-    public synchronized void setMinSize(long size) {
+    public void setMinSize(long size) {
         minSize = size;
     }
 

activemq-kahadb-store/src/main/java/org/apache/activemq/store/kahadb/disk/index/HashIndex.java

@@ -122,7 +122,7 @@ public class HashIndex<Key,Value> implements Index<Key,Value> {
     
     private Metadata.Marshaller metadataMarshaller = new Metadata.Marshaller();
     private HashBin.Marshaller<Key,Value> hashBinMarshaller = new HashBin.Marshaller<Key,Value>(this);
-    private Marshaller<Key> keyMarshaller;
+    private volatile Marshaller<Key> keyMarshaller;
     private Marshaller<Value> valueMarshaller;
 
     
@@ -392,7 +392,7 @@ public class HashIndex<Key,Value> implements Index<Key,Value> {
      * 
      * @param marshaller
      */
-    public synchronized void setKeyMarshaller(Marshaller<Key> marshaller) {
+    public void setKeyMarshaller(Marshaller<Key> marshaller) {
         this.keyMarshaller = marshaller;
     }