RE: Memory leak in 7.0.3 JDBC driver

I posted yesterday regarding a memory leak I found in the JDBC driver in
7.1. I didn't check but it is quite likely it also existed in 7.0. The patch
I created hasn't been checked by anyone else yet so I don't know if it helps
for others or not. Feel free to try it.

--Rainer


> -----Original Message-----
> From: pgsql-bugs-owner@postgresql.org
> [mailto:pgsql-bugs-owner@postgresql.org]On Behalf Of Steve Sullivan
> Sent: Monday, June 18, 2001 2:59 AM
> To: pgsql-bugs@postgresql.org
> Subject: [BUGS] Memory leak in 7.0.3 JDBC driver
>
>
>
> Hi,
>
> I'm running Postgresql 7.0.3 on Redhat 7.1 on a Pentium.
> When I use Connection.getCatalog() and similar calls,
> the amount of free memory slowly decreases.  I get:
>
> after get catalog: 0:  totmem: 2031616 freemem: 1899480
> after get catalog: 100:  totmem: 2031616 freemem: 1854576
> after get catalog: 200:  totmem: 2031616 freemem: 1810008
> after get catalog: 300:  totmem: 2031616 freemem: 1765104
> after get catalog: 400:  totmem: 2031616 freemem: 1720200
> after get catalog: 500:  totmem: 2031616 freemem: 1675296
> after get catalog: 600:  totmem: 2031616 freemem: 1630808
> after get catalog: 700:  totmem: 2031616 freemem: 1585904
> after get catalog: 800:  totmem: 2031616 freemem: 1541000
> after get catalog: 900:  totmem: 2031616 freemem: 1496096
>
> It's losing about 448 bytes per iteration.
> The Java test program I wrote is appended.  I invoked it using:
>
> java Tbtestc org.postgresql.Driver jdbc:postgresql:mydb myuser
> mypswd testtablea > loga
>
> If you need any further info, please contact me.
> Thanks,
>
> Steve
>
> ========================================
> Steve Sullivan    sullivan@mathcom.com
>
>    Mathcom Solutions, Inc.
>     * Java, XML, and web oriented development.
>     * Language development and translation.
>     * Optimization, simulation, and mathematical modeling.
>
> http://www.mathcom.com    303-494-7115
> ========================================
>
>
>
> ========== begin Tbtestc.java ==========
>
> import java.io.PrintWriter;
> import java.sql.Connection;
> import java.sql.DatabaseMetaData;
> import java.sql.DriverManager;
> import java.sql.PreparedStatement;
> import java.sql.ResultSet;
> import java.sql.ResultSetMetaData;
> import java.sql.SQLException;
> import java.sql.Statement;
> import java.sql.Types;
>
> /**
>  * Tests simple jdbc access for memory leaks.
>  */
>
>
> public class Tbtestc {
>     public static void main( String[] args) {
>         new Tbtestc( args);
>     }
>
>     void prtln( String msg) {
>         System.out.println( msg);
>     }
>
>     void badparms( String msg)
>     {
>         prtln("");
>         prtln("Testc: Error: " + msg);
>         prtln("args:  drivername url userid pswd tabname
> (will be deleted)");
>         System.exit(1);
>     }
>
>
>     public Tbtestc( String[] args) {
>         int ii;
>
>         if (args.length != 5) badparms("wrong num parms");
>         String drivername    = args[0];
>         String url            = args[1];
>         String userid        = args[2];
>         String pswd            = args[3];
>         String tabname        = args[4];
>
>         // Connect to database and run the tests
>         try {
>             testit( drivername, url, userid, pswd, tabname);
>         }
>         catch( Exception exc) {
>             prtln("Tbtestc: error: " + exc);
>             exc.printStackTrace();
>         }
>     }
>
>
>     void testit(
>         String drivername,
>         String url,
>         String userid,
>         String pswd,
>         String tabname)
>     throws SQLException, ClassNotFoundException
>     {
>         int iterlim = 1000;
>         int iterdelta = 100;
>         int ii, jj, kk;
>         int ncols;
>         String tstg;
>         ResultSet rs = null;
>         int maxcolwidth = 30;
>
>         Connection dbcon = null;
>         Statement dbst = null;
>
>         // Load the driver
>         Class.forName( drivername);
>
>         prtln("Connecting to Database URL = " + url);
>         dbcon = DriverManager.getConnection( url, userid, pswd);
>         prtln("got dbcon.");
>         dbst = dbcon.createStatement();
>         prtln("got dbst.");
>
>         try { dbst.executeUpdate("drop table " + tabname); }
>         catch( SQLException sqe) {
>             prtln("could not drop table " + tabname +
> ": " + sqe);
>         }
>
>         dbst.executeUpdate("create table " + tabname
>             + " (colstg varchar(22) not null,"
>             + " colint integer not null,"
>             + " primary key (colstg, colint))");
>         prtln("testit: created " + tabname);
>
>         prtfreemem("before get catalog");
>         String catalog = null;
>         int isol = 0;
>         boolean readonly = false;
>         boolean autocommit = false;
>         for (kk = 0; kk < iterlim; kk++) {
>             catalog = dbcon.getCatalog();
>             isol = dbcon.getTransactionIsolation();
>             readonly = dbcon.isReadOnly();
>             autocommit = dbcon.getAutoCommit();
>             if (kk % iterdelta == 0) prtfreemem("after
> get catalog: " + kk);
>         }
>         prtfreemem("after get catalog");
>         prtln("    catalog: " + catalog);
>         prtln("    transaction isolation level: " + isol);
>         prtln("    read only: " + readonly);
>         prtln("    auto commit: " + autocommit);
>
>         DatabaseMetaData dbm = null;
>         for (kk = 0; kk < iterlim; kk++) {
>             dbm = dbcon.getMetaData();
>             if (kk % iterdelta == 0) prtfreemem("after
> get dbm: " + kk);
>         }
>         prtfreemem("after get dbm");
>         String prodname = null;
>         String version = null;
>         String geturl = null;
>         String getuser = null;
>         for (kk = 0; kk < iterlim; kk++) {
>             prodname = dbm.getDatabaseProductName();
>             version = dbm.getDatabaseProductVersion();
>             geturl = dbm.getURL();
>             getuser = dbm.getUserName();
>             if (kk % iterdelta == 0) prtfreemem("after
> get prodname: " + kk);
>         }
>         prtfreemem("after get prodname");
>         prtln("database meta data:");
>         prtln("    product name: " + prodname);
>         prtln("    version: " + version);
>         prtln("    URL: " + geturl);
>         prtln("    user: " + getuser);
>
>         for (kk = 0; kk < iterlim; kk++) {
>             ResultSet keyrs = dbm.getPrimaryKeys(
>                 null, null,            //
> catalog, schema
>                 tabname);
>             keyrs.close();
>             if (kk % iterdelta == 0) prtfreemem("after
> get keys: " + kk);
>         }
>         prtfreemem("after get keys");
>
>     }
>
>
>
>     void prtfreemem( String msgparm) {
>         Runtime runtime = Runtime.getRuntime();
>         runtime.gc();
>         long totmem = runtime.totalMemory();
>         long freemem = runtime.freeMemory();
>         String msg = msgparm + ": "
>             + " totmem: " + totmem
>             + " freemem: " + freemem;
>         System.out.println( msg);
>     }
>
>
> } // end class Tbtestc
>
>
> ========== end Tbtestc.java ==========
>
> ---------------------------(end of broadcast)---------------------------
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