bug fixed : mysql performance

src/main/java/com/alibaba/druid/pool/ConnectionHolder.java

@@ -51,6 +51,11 @@ public final class ConnectionHolder {
 
     private final boolean                       defaultAutoCommit;
 
+    private boolean                             underlyingReadOnly;
+    private int                                 underlyingHoldability;
+    private int                                 underlyingTransactionIsolation;
+    private boolean                             underlyingAutoCommit;
+
     public ConnectionHolder(DruidAbstractDataSource dataSource, Connection conn) throws SQLException{
         this.dataSource = dataSource;
         this.conn = conn;
@@ -61,10 +66,47 @@ public final class ConnectionHolder {
         this.defaultHoldability = conn.getHoldability();
         this.defaultTransactionIsolation = conn.getTransactionIsolation();
         this.defaultAutoCommit = conn.getAutoCommit();
+        
+        this.underlyingAutoCommit = defaultAutoCommit;
+        this.underlyingHoldability = defaultHoldability;
+        this.underlyingTransactionIsolation = defaultTransactionIsolation;
+        this.underlyingTransactionIsolation = defaultTransactionIsolation;
 
         statementPool = null;
     }
 
+    public boolean isUnderlyingReadOnly() {
+        return underlyingReadOnly;
+    }
+
+    public void setUnderlyingReadOnly(boolean underlyingReadOnly) {
+        this.underlyingReadOnly = underlyingReadOnly;
+    }
+
+    public int getUnderlyingHoldability() {
+        return underlyingHoldability;
+    }
+
+    public void setUnderlyingHoldability(int underlyingHoldability) {
+        this.underlyingHoldability = underlyingHoldability;
+    }
+
+    public int getUnderlyingTransactionIsolation() {
+        return underlyingTransactionIsolation;
+    }
+
+    public void setUnderlyingTransactionIsolation(int underlyingTransactionIsolation) {
+        this.underlyingTransactionIsolation = underlyingTransactionIsolation;
+    }
+
+    public boolean isUnderlyingAutoCommit() {
+        return underlyingAutoCommit;
+    }
+
+    public void setUnderlyingAutoCommit(boolean underlyingAutoCommit) {
+        this.underlyingAutoCommit = underlyingAutoCommit;
+    }
+
     public long getLastActiveTimeMillis() {
         return lastActiveTimeMillis;
     }
@@ -122,19 +164,19 @@ public final class ConnectionHolder {
 
     public void reset() throws SQLException {
         // reset default settings
-        if (conn.isReadOnly() != defaultReadOnly) {
+        if (underlyingReadOnly != defaultReadOnly) {
             conn.setReadOnly(defaultReadOnly);
         }
 
-        if (conn.getHoldability() != defaultHoldability) {
+        if (underlyingHoldability != defaultHoldability) {
             conn.setHoldability(defaultHoldability);
         }
 
-        if (conn.getTransactionIsolation() != defaultTransactionIsolation) {
+        if (underlyingTransactionIsolation != defaultTransactionIsolation) {
             conn.setTransactionIsolation(defaultTransactionIsolation);
         }
-        
-        if (conn.getAutoCommit() != defaultAutoCommit) {
+
+        if (underlyingAutoCommit != defaultAutoCommit) {
             conn.setAutoCommit(defaultAutoCommit);
         }
 
@@ -146,7 +188,7 @@ public final class ConnectionHolder {
             JdbcUtils.close(stmt);
         }
         statementTrace.clear();
-        
+
         conn.clearWarnings();
     }
 

src/main/java/com/alibaba/druid/pool/PoolableConnection.java

@@ -91,7 +91,7 @@ public class PoolableConnection implements PooledConnection, Connection {
     }
 
     void closePoolableStatement(PoolablePreparedStatement stmt) throws SQLException {
-        if (this.isClosed()) {
+        if (this.holder == null) {
             return;
         }
 
@@ -585,6 +585,7 @@ public class PoolableConnection implements PooledConnection, Connection {
 
         try {
             conn.setAutoCommit(autoCommit);
+            holder.setUnderlyingAutoCommit(autoCommit);
         } catch (SQLException ex) {
             handleException(ex);
         }
@@ -728,6 +729,7 @@ public class PoolableConnection implements PooledConnection, Connection {
         checkOpen();
 
         conn.setReadOnly(readOnly);
+        holder.setUnderlyingReadOnly(readOnly);
     }
 
     @Override
@@ -756,6 +758,7 @@ public class PoolableConnection implements PooledConnection, Connection {
         checkOpen();
 
         conn.setTransactionIsolation(level);
+        holder.setUnderlyingTransactionIsolation(level);
     }
 
     @Override
@@ -798,6 +801,7 @@ public class PoolableConnection implements PooledConnection, Connection {
         checkOpen();
 
         conn.setHoldability(holdability);
+        holder.setUnderlyingHoldability(holdability);
     }
 
     @Override