diff --git a/src/main/java/com/alibaba/druid/wall/WallConfig.java b/src/main/java/com/alibaba/druid/wall/WallConfig.java
index ac0fb0a2a6..7d1e94f186 100644
--- a/src/main/java/com/alibaba/druid/wall/WallConfig.java
+++ b/src/main/java/com/alibaba/druid/wall/WallConfig.java
@@ -29,6 +29,8 @@ public class WallConfig {
 
     private boolean             truncateAllow              = false;
 
+    private boolean             commentAllow               = false;
+
     private boolean             schemaCheck                = true;
     private boolean             tableCheck                 = true;
     private boolean             functionCheck              = true;
@@ -238,6 +240,14 @@ public class WallConfig {
 
     // ///////////////////
 
+    public boolean isCommentAllow() {
+        return commentAllow;
+    }
+
+    public void setCommentAllow(boolean commentAllow) {
+        this.commentAllow = commentAllow;
+    }
+
     public Set<String> getPermitFunctions() {
         return permitFunctions;
     }
diff --git a/src/main/java/com/alibaba/druid/wall/WallProvider.java b/src/main/java/com/alibaba/druid/wall/WallProvider.java
index ee11378342..ca0c5790a4 100644
--- a/src/main/java/com/alibaba/druid/wall/WallProvider.java
+++ b/src/main/java/com/alibaba/druid/wall/WallProvider.java
@@ -4,6 +4,7 @@ import java.util.ArrayList;
 import java.util.Collections;
 import java.util.LinkedHashMap;
 import java.util.List;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
 
 import com.alibaba.druid.sql.ast.SQLStatement;
 import com.alibaba.druid.sql.parser.ParserException;
@@ -19,10 +20,12 @@ public abstract class WallProvider {
 
     private int                           whileListMaxSize  = 1024;
 
-    private int                           whiteSqlMaxLength = 1024;        // 1k
+    private int                           whiteSqlMaxLength = 1024;                        // 1k
 
     protected final WallConfig            config;
 
+    private final ReentrantReadWriteLock  lock              = new ReentrantReadWriteLock();
+
     public WallProvider(WallConfig config){
         this.config = config;
     }
@@ -31,26 +34,36 @@ public abstract class WallProvider {
         return config;
     }
 
-    public synchronized void addWhiteSql(String sql) {
-        if (whiteList == null) {
-            whiteList = new LinkedHashMap<String, Object>(whileListMaxSize, 0.75f, true);
-        }
+    public void addWhiteSql(String sql) {
+        lock.writeLock().lock();
+        try {
+            if (whiteList == null) {
+                whiteList = new LinkedHashMap<String, Object>(whileListMaxSize, 0.75f, true);
+            }
 
-        whiteList.put(sql, PRESENT);
+            whiteList.put(sql, PRESENT);
+        } finally {
+            lock.writeLock().unlock();
+        }
     }
 
-    public synchronized boolean whiteContains(String sql) {
-        if (whiteList == null) {
-            return false;
-        }
+    public boolean whiteContains(String sql) {
+        lock.readLock().lock();
+        try {
+            if (whiteList == null) {
+                return false;
+            }
 
-        return whiteList.get(sql) != null;
+            return whiteList.get(sql) != null;
+        } finally {
+            lock.readLock().unlock();
+        }
     }
 
     public abstract SQLStatementParser createParser(String sql);
 
     public abstract WallVisitor createWallVisitor();
-    
+
     public boolean checkValid(String sql) {
         return check(sql).size() == 0;
     }
@@ -63,7 +76,10 @@ public abstract class WallProvider {
         }
 
         SQLStatementParser parser = createParser(sql);
-        parser.getLexer().setAllowComment(false); // permit comment
+
+        if (!config.isCommentAllow()) {
+            parser.getLexer().setAllowComment(false); // permit comment
+        }
 
         List<SQLStatement> statementList = new ArrayList<SQLStatement>();
 
diff --git a/src/main/resources/META-INF/druid/wall/sqlserver/permit-table.txt b/src/main/resources/META-INF/druid/wall/sqlserver/permit-table.txt
index c2b14c048c..9ec6dc3f53 100644
--- a/src/main/resources/META-INF/druid/wall/sqlserver/permit-table.txt
+++ b/src/main/resources/META-INF/druid/wall/sqlserver/permit-table.txt
@@ -55,44 +55,44 @@ backupset
 sysdatabases
 sysservers
 sysreplicationalerts
-MSagent_parameters
-Mspublisher_databases
-MSagent_profiles
-MSreplication_objects
-MSarticles
-MSreplication_subscriptions
-MSdistpublishers
-MSrepl_commands
-MSdistributiondbs
-MSrepl_errors
-MSdistribution_agents
-MSrepl_originators
-MSdistribution_history
-MSrepl_transactions
-MSdistributor
-MSrepl_version
-MSlogreader_agents
-MSsnapshot_agents
-MSlogreader_history
-MSsnapshot_history
-MSmerge_agents
-MSsubscriber_info
-MSmerge_history
-MSsubscriber_schedule
-MSmerge_subscriptions
-MSsubscriptions
-MSpublication_access
-MSsubscription_properties
-Mspublications
-MSmerge_contents
+msagent_parameters
+mspublisher_databases
+msagent_profiles
+msreplication_objects
+msarticles
+msreplication_subscriptions
+msdistpublishers
+msrepl_commands
+msdistributiondbs
+msrepl_errors
+msdistribution_agents
+msrepl_originators
+msdistribution_history
+msrepl_transactions
+msdistributor
+msrepl_version
+mslogreader_agents
+mssnapshot_agents
+mslogreader_history
+mssnapshot_history
+msmerge_agents
+mssubscriber_info
+msmerge_history
+mssubscriber_schedule
+msmerge_subscriptions
+mssubscriptions
+mspublication_access
+mssubscription_properties
+mspublications
+msmerge_contents
 sysmergearticles
-MSmerge_delete_conflicts
+msmerge_delete_conflicts
 sysmergepublications
-MSmerge_genhistory
+msmerge_genhistory
 sysmergeschemachange
-MSmerge_replinfo
+msmerge_replinfo
 sysmergesubscriptions
-MSmerge_tombstone
+msmerge_tombstone
 sysmergesubsetfilters
 sysarticles
 syspublications
diff --git a/src/test/resources/com/alibaba/druid/pool/spring-config-1.xml b/src/test/resources/com/alibaba/druid/pool/spring-config-1.xml
index 65bb5086b2..40e604ac01 100644
--- a/src/test/resources/com/alibaba/druid/pool/spring-config-1.xml
+++ b/src/test/resources/com/alibaba/druid/pool/spring-config-1.xml
@@ -22,7 +22,7 @@ http://www.springframework.org/schema/aop http://www.springframework.org/schema/
 		<property name="config" ref="wall-filter-config" />
 	</bean>
 
-	<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"
+	<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" init-method="init"
 		destroy-method="close">
 		<property name="url">
 			<value>jdbc:mock:</value>