2014-08-08 4:04 GMT+04:00 <[email protected]>:
> Author: fhanik
> Date: Fri Aug 8 00:04:51 2014
> New Revision: 1616644
>
> URL: http://svn.apache.org/r1616644
> Log:
> Fix https://issues.apache.org/bugzilla/show_bug.cgi?id=56318
> Contribution by Danila Galimov
> Ability to log statement creation stacks
>
> Modified:
> tomcat/trunk/modules/jdbc-pool/doc/jdbc-pool.xml
>
> tomcat/trunk/modules/jdbc-pool/src/main/java/org/apache/tomcat/jdbc/pool/interceptor/StatementFinalizer.java
>
> Modified: tomcat/trunk/modules/jdbc-pool/doc/jdbc-pool.xml
> URL:
> http://svn.apache.org/viewvc/tomcat/trunk/modules/jdbc-pool/doc/jdbc-pool.xml?rev=1616644&r1=1616643&r2=1616644&view=diff
> ==============================================================================
> --- tomcat/trunk/modules/jdbc-pool/doc/jdbc-pool.xml (original)
> +++ tomcat/trunk/modules/jdbc-pool/doc/jdbc-pool.xml Fri Aug 8 00:04:51 2014
> @@ -608,6 +608,13 @@
> and closes these statements when the connection is returned to the
> pool.
> </p>
> <attributes>
> + <attribute name="trace" required="false">
> + <p>(boolean as String) Enable tracing of unclosed statements.
> + When enabled and a connection is closed, and statements are not
> closed,
> + the interceptor will log all stack traces.
> + The default value is <code>false</code>.
> + </p>
> + </attribute>
> </attributes>
> </subsection>
> <subsection name="org.apache.tomcat.jdbc.pool.interceptor.StatementCache">
>
> Modified:
> tomcat/trunk/modules/jdbc-pool/src/main/java/org/apache/tomcat/jdbc/pool/interceptor/StatementFinalizer.java
> URL:
> http://svn.apache.org/viewvc/tomcat/trunk/modules/jdbc-pool/src/main/java/org/apache/tomcat/jdbc/pool/interceptor/StatementFinalizer.java?rev=1616644&r1=1616643&r2=1616644&view=diff
> ==============================================================================
> ---
> tomcat/trunk/modules/jdbc-pool/src/main/java/org/apache/tomcat/jdbc/pool/interceptor/StatementFinalizer.java
> (original)
> +++
> tomcat/trunk/modules/jdbc-pool/src/main/java/org/apache/tomcat/jdbc/pool/interceptor/StatementFinalizer.java
> Fri Aug 8 00:04:51 2014
> @@ -19,6 +19,7 @@ package org.apache.tomcat.jdbc.pool.inte
> import org.apache.juli.logging.Log;
> import org.apache.juli.logging.LogFactory;
> import org.apache.tomcat.jdbc.pool.ConnectionPool;
> +import org.apache.tomcat.jdbc.pool.PoolProperties;
> import org.apache.tomcat.jdbc.pool.PooledConnection;
>
> import java.lang.ref.WeakReference;
> @@ -26,6 +27,8 @@ import java.lang.reflect.Method;
> import java.sql.Statement;
> import java.util.LinkedList;
> import java.util.List;
> +import java.util.Map;
> +
> /**
> * Keeps track of statements associated with a connection and invokes close
> upon {@link java.sql.Connection#close()}
> * Useful for applications that dont close the associated statements after
> being done with a connection.
> @@ -34,13 +37,15 @@ import java.util.List;
> public class StatementFinalizer extends AbstractCreateStatementInterceptor {
> private static final Log log =
> LogFactory.getLog(StatementFinalizer.class);
>
> - protected List<WeakReference<Statement>> statements = new LinkedList<>();
> -
> + protected List<WeakReference<StatementEntry>> statements = new
> LinkedList<>();
1. This approach is broken.
Essentially this change breaks StatementFinalizer.
A weak reference to a Statement is OK, because there are hard
references to that statement object elsewhere.
A weak reference to a StatementEntry class is not OK, because it is
the only reference to it. It is immediately eligible to be
garbage-collected.
> +
> + private boolean logCreationStack = false;
> +
> @Override
> public Object createStatement(Object proxy, Method method, Object[]
> args, Object statement, long time) {
> try {
> if (statement instanceof Statement)
> - statements.add(new WeakReference<>((Statement)statement));
> + statements.add(new WeakReference<>(new
> StatementEntry((Statement)statement)));
> }catch (ClassCastException x) {
> //ignore this one
> }
> @@ -50,25 +55,58 @@ public class StatementFinalizer extends
> @Override
> public void closeInvoked() {
> while (statements.size()>0) {
> - WeakReference<Statement> ws = statements.remove(0);
> - Statement st = ws.get();
> + WeakReference<StatementEntry> ws = statements.remove(0);
> + StatementEntry st = ws.get();
> if (st!=null) {
> try {
> - st.close();
> + st.getStatement().close();
> } catch (Exception ignore) {
> if (log.isDebugEnabled()) {
> log.debug("Unable to closed statement upon
> connection close.",ignore);
> }
> }
> + if (logCreationStack) {
> + log.warn("Statement created, but was not closed at:",
> st.getAllocationStack());
> + }
> }
> }
> }
>
> @Override
> + public void setProperties(Map<String,
> PoolProperties.InterceptorProperty> properties) {
> + super.setProperties(properties);
> +
> + PoolProperties.InterceptorProperty logProperty =
> properties.get("trace");
> + if (null != logProperty) {
> + logCreationStack =
> logProperty.getValueAsBoolean(logCreationStack);
> + }
> + }
> +
> + @Override
> public void reset(ConnectionPool parent, PooledConnection con) {
> statements.clear();
> super.reset(parent, con);
> }
>
> + protected class StatementEntry {
> + private Statement statement;
> + private Throwable allocationStack;
2. Missing "final".
> +
> + public StatementEntry(Statement statement) {
> + this.statement = statement;
> + if (logCreationStack) {
> + this.allocationStack = new Throwable();
> + }
> + }
> +
> + public Statement getStatement() {
> + return statement;
> + }
> +
> + public Throwable getAllocationStack() {
> + return allocationStack;
> + }
> + }
> +
Best regards,
Konstantin Kolinko
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