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Posted to general@db.apache.org by ma...@apache.org on 2012/09/21 02:58:30 UTC
svn commit: r1388285 - in /db/derby/code/branches/10.5: ./ java/
java/client/org/apache/derby/client/am/LogicalConnection.java
Author: mamta
Date: Fri Sep 21 00:58:29 2012
New Revision: 1388285
URL: http://svn.apache.org/viewvc?rev=1388285&view=rev
Log:
DERBY-5561(Race conditions in LogicalConnection checking for a null physical connection )
Backporting to 10.5 codeline
Modified:
db/derby/code/branches/10.5/ (props changed)
db/derby/code/branches/10.5/java/ (props changed)
db/derby/code/branches/10.5/java/client/org/apache/derby/client/am/LogicalConnection.java
Propchange: db/derby/code/branches/10.5/
------------------------------------------------------------------------------
Merged /db/derby/code/branches/10.7:r1383996
Merged /db/derby/code/trunk:r1333305,1334919
Propchange: db/derby/code/branches/10.5/java/
------------------------------------------------------------------------------
Merged /db/derby/code/branches/10.7/java:r1383996
Modified: db/derby/code/branches/10.5/java/client/org/apache/derby/client/am/LogicalConnection.java
URL: http://svn.apache.org/viewvc/db/derby/code/branches/10.5/java/client/org/apache/derby/client/am/LogicalConnection.java?rev=1388285&r1=1388284&r2=1388285&view=diff
==============================================================================
--- db/derby/code/branches/10.5/java/client/org/apache/derby/client/am/LogicalConnection.java (original)
+++ db/derby/code/branches/10.5/java/client/org/apache/derby/client/am/LogicalConnection.java Fri Sep 21 00:58:29 2012
@@ -24,17 +24,26 @@ import org.apache.derby.shared.common.re
import java.sql.SQLException;
-
-// A simple delegation wrapper handle for a physical connection.
-// All methods are forwarded to the underlying physical connection except for close() and isClosed().
-// When a physical connection is wrapped, it is non-null, when the logical connection
-// is closed, the wrapped physical connection is always set to null.
-// Both the finalizer and close() methods will always set the physical connection to null.
-// After the physical conneciton is set to null,
-// only the Pooled Connection instance will maintain a handle to the physical connection.
-
+/**
+ * A simple delegation wrapper handle for a physical connection.
+ * <p>
+ * All methods of the {@code Connection} interface are forwarded to the
+ * underlying physical connection, except for {@link #close()} and
+ * {@link #isClosed()}. When a physical connection is wrapped, it is non-null,
+ * when the logical connection is closed, the wrapped physical connection is
+ * always set to {@code null}.
+ * Both the finalizer and the {@code close}-methods will always set the
+ * physical connection to {@code null}. After the physical connection has been
+ * nulled out, only the {@code PooledConnection} instance will maintain a
+ * handle to the physical connection.
+ */
public class LogicalConnection implements java.sql.Connection {
- protected Connection physicalConnection_ = null; // reset to null when the logical connection is closed.
+ /**
+ * Underlying physical connection for this logical connection.
+ * <p>
+ * Set to {@code null} when this logical connection is closed.
+ */
+ Connection physicalConnection_;
private org.apache.derby.client.ClientPooledConnection pooledConnection_ = null;
/**
* Logical database metadata object created on demand and then cached.
@@ -129,10 +138,17 @@ public class LogicalConnection implement
// --------------------------- helper methods --------------------------------
- // this method doesn't wrap in the standard way, because it went out without a throws clause.
- // Unlike all other LogicalConnection methods, if the physical connection is null, it won't throw an exception, but will return false.
-
- protected void checkForNullPhysicalConnection() throws SQLException {
+ /**
+ * Verifies that there is an underlying physical connection for this
+ * logical connection.
+ * <p>
+ * If the physical connection has been nulled out it means that this
+ * logical connection has been closed.
+ *
+ * @throws SQLException if this logical connection has been closed
+ */
+ protected final void checkForNullPhysicalConnection()
+ throws SQLException {
if (physicalConnection_ == null) {
SqlException se = new SqlException(null,
new ClientMessageId(SQLState.NO_CURRENT_CONNECTION));
@@ -141,14 +157,14 @@ public class LogicalConnection implement
}
/**
- * This method checks if the physcial connection underneath is null and
- * if yes, then it simply returns.
- * Otherwise, if the severity of exception is greater than equal to
- * ExceptionSeverity.SESSION_SEVERITY, then we will send
- * connectionErrorOccurred event to all the registered listeners.
+ * Notifies listeners about exceptions of session level severity or higher.
+ * <p>
+ * The exception, even if the severity is sufficiently high, is ignored if
+ * the underlying physical connection has been nulled out. Otherwise a
+ * {@code connectionErrorOccurred}-event is sent to all the registered
+ * listeners.
*
- * @param sqle SQLException An event will be sent to the listeners if the
- * exception's severity is >= ExceptionSeverity.SESSION_SEVERITY.
+ * @param sqle the cause of the notification
*/
final void notifyException(SQLException sqle) {
if (physicalConnection_ != null)
@@ -197,7 +213,7 @@ public class LogicalConnection implement
}
}
- public String nativeSQL(String sql) throws SQLException {
+ synchronized public String nativeSQL(String sql) throws SQLException {
try {
checkForNullPhysicalConnection();
return physicalConnection_.nativeSQL(sql);
@@ -217,7 +233,7 @@ public class LogicalConnection implement
}
}
- public boolean getAutoCommit() throws SQLException {
+ synchronized public boolean getAutoCommit() throws SQLException {
try {
checkForNullPhysicalConnection();
return physicalConnection_.getAutoCommit();
@@ -257,7 +273,7 @@ public class LogicalConnection implement
}
}
- public int getTransactionIsolation() throws SQLException {
+ synchronized public int getTransactionIsolation() throws SQLException {
try {
checkForNullPhysicalConnection();
return physicalConnection_.getTransactionIsolation();
@@ -267,7 +283,7 @@ public class LogicalConnection implement
}
}
- public java.sql.SQLWarning getWarnings() throws SQLException {
+ synchronized public java.sql.SQLWarning getWarnings() throws SQLException {
try {
checkForNullPhysicalConnection();
return physicalConnection_.getWarnings();
@@ -363,7 +379,7 @@ public class LogicalConnection implement
}
}
- public boolean isReadOnly() throws SQLException {
+ synchronized public boolean isReadOnly() throws SQLException {
try {
checkForNullPhysicalConnection();
return physicalConnection_.isReadOnly();
@@ -383,7 +399,7 @@ public class LogicalConnection implement
}
}
- public String getCatalog() throws SQLException {
+ synchronized public String getCatalog() throws SQLException {
try {
checkForNullPhysicalConnection();
return physicalConnection_.getCatalog();
@@ -428,7 +444,7 @@ public class LogicalConnection implement
}
}
- public java.util.Map getTypeMap() throws SQLException {
+ synchronized public java.util.Map getTypeMap() throws SQLException {
try {
checkForNullPhysicalConnection();
return physicalConnection_.getTypeMap();
@@ -448,7 +464,7 @@ public class LogicalConnection implement
}
}
- public java.sql.Statement createStatement(int resultSetType, int resultSetConcurrency,
+ synchronized public java.sql.Statement createStatement(int resultSetType, int resultSetConcurrency,
int resultSetHoldability) throws SQLException {
try {
checkForNullPhysicalConnection();
@@ -459,7 +475,7 @@ public class LogicalConnection implement
}
}
- public java.sql.CallableStatement prepareCall(String sql, int resultSetType,
+ synchronized public java.sql.CallableStatement prepareCall(String sql, int resultSetType,
int resultSetConcurrency,
int resultSetHoldability) throws SQLException {
try {
@@ -471,7 +487,7 @@ public class LogicalConnection implement
}
}
- public java.sql.PreparedStatement prepareStatement(String sql, int resultSetType,
+ synchronized public java.sql.PreparedStatement prepareStatement(String sql, int resultSetType,
int resultSetConcurrency, int resultSetHoldability)
throws SQLException {
try {
@@ -484,7 +500,7 @@ public class LogicalConnection implement
}
}
- public java.sql.PreparedStatement prepareStatement(String sql, int autoGeneratedKeys)
+ synchronized public java.sql.PreparedStatement prepareStatement(String sql, int autoGeneratedKeys)
throws SQLException {
try {
checkForNullPhysicalConnection();
@@ -495,7 +511,7 @@ public class LogicalConnection implement
}
}
- public java.sql.PreparedStatement prepareStatement(String sql, int columnIndexes[])
+ synchronized public java.sql.PreparedStatement prepareStatement(String sql, int columnIndexes[])
throws SQLException {
try {
checkForNullPhysicalConnection();
@@ -506,7 +522,7 @@ public class LogicalConnection implement
}
}
- public java.sql.PreparedStatement prepareStatement(String sql, String columnNames[])
+ synchronized public java.sql.PreparedStatement prepareStatement(String sql, String columnNames[])
throws SQLException {
try {
checkForNullPhysicalConnection();
@@ -517,7 +533,7 @@ public class LogicalConnection implement
}
}
- public void setHoldability(int holdability) throws SQLException {
+ synchronized public void setHoldability(int holdability) throws SQLException {
try {
checkForNullPhysicalConnection();
physicalConnection_.setHoldability(holdability);
@@ -527,7 +543,7 @@ public class LogicalConnection implement
}
}
- public int getHoldability() throws SQLException {
+ synchronized public int getHoldability() throws SQLException {
try {
checkForNullPhysicalConnection();
return physicalConnection_.getHoldability();
@@ -537,7 +553,7 @@ public class LogicalConnection implement
}
}
- public java.sql.Savepoint setSavepoint() throws SQLException {
+ synchronized public java.sql.Savepoint setSavepoint() throws SQLException {
try {
checkForNullPhysicalConnection();
return physicalConnection_.setSavepoint();
@@ -547,7 +563,7 @@ public class LogicalConnection implement
}
}
- public java.sql.Savepoint setSavepoint(String name) throws SQLException {
+ synchronized public java.sql.Savepoint setSavepoint(String name) throws SQLException {
try {
checkForNullPhysicalConnection();
return physicalConnection_.setSavepoint(name);
@@ -557,7 +573,7 @@ public class LogicalConnection implement
}
}
- public void rollback(java.sql.Savepoint savepoint) throws SQLException {
+ synchronized public void rollback(java.sql.Savepoint savepoint) throws SQLException {
try {
checkForNullPhysicalConnection();
physicalConnection_.rollback(savepoint);
@@ -567,7 +583,7 @@ public class LogicalConnection implement
}
}
- public void releaseSavepoint(java.sql.Savepoint savepoint) throws SQLException {
+ synchronized public void releaseSavepoint(java.sql.Savepoint savepoint) throws SQLException {
try {
checkForNullPhysicalConnection();
physicalConnection_.releaseSavepoint(savepoint);