Re: BUG #5269: postgres backend terminates with SIGSEGV - Mailing list pgsql-bugs

Apologies for over-quoting on the previous message.

My approach to a regression test was this single-threaded test ( actual cod=
e at bottom )=20

    Connection 1 - implicitly autocommiting every statement
        create a test table and populate it with a single row.=20
            CREATE TABLE FOO ( a int not null );
            INSERT INTO FOO VALUES (1);
        set the connection autocommit to false ( implied transaction begin on nex=
t statement )
        read=20
            SELECT * FROM FOO;
        modify
            UPDATE FOO SET a=3Da+1;
        ( transaction is still open )
    Connection 2
        set the connection autocommit to false
        read
            SELECT * FROM FOO;
    Connection 1
        commit;
    Connection 2
        modify
            UPDATE FOO SET a=3Da+1
        throws concurrent serialization error
    Connection 3
        do a bunch of catalog updates
            for f in 1..??? ( i tried 1, 10, 100, and 4096 )
                CREATE TEMP TABLE BAR$f (a int not null );
    Connection 2
        rollback <- I am expecting a server crash here. It does not crash.



My guess is that I am not provoking a 'SI queue overrun'=20
( I am assuming this is a reference to the queue implemented in sinvaladt.c=
. My C skills are rusty at best. )

Am I completely off base about how this should be reproducing?


Bug5269Test.java

import java.sql.Connection;
import java.sql.Driver;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;

/* Regression test for PostgreSQL Bug # 5269=20
 * http://archives.postgresql.org/pgsql-bugs/2010-01/msg00080.php=20
 * */

public class Bug5269Test {

    private Connection newConnection(Driver driver) {
        Properties info =3D new Properties();
        info.put("user", "postgres");
        try {
            return driver.connect("jdbc:postgresql://localhost:5433", info);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return null;
    }

    public void test() throws SQLException, InterruptedException {
        Driver driver =3D new org.postgresql.Driver();
        Connection a =3D newConnection(driver);
        setupTable(a);

        Connection b =3D newConnection(driver);
        a.setAutoCommit(false);
        a.setTransactionIsolation(Connection.TRANSACTION_SERIALIZABLE);
        b.setAutoCommit(false);
        b.setTransactionIsolation(Connection.TRANSACTION_SERIALIZABLE);

        String select =3D "select * from foo";
        String update =3D "update foo set a =3D a + 1";

        a.prepareStatement(select).execute();
        System.out.println("select a");

        a.prepareStatement(update).execute();
        System.out.println("update a");

        b.prepareStatement(select).execute();
        System.out.println("select b");

        a.commit();
        System.out.println("commit a");
        try {
            b.prepareStatement(update).execute();
            b.commit();
            throw new RuntimeException("Expected a serialization failure.");
        } catch (SQLException sqle) {
            System.out.println(sqle.getMessage());
            flogCatalogs(driver);
            System.out.println("flog catalogs");

            // The hope is that an unpatched system would crash here.
            b.rollback();
            System.out.println("rollback.");
        }
        a.close();
        b.close();
    }

    private void setupTable(Connection a) throws SQLException {
        try {
            a.prepareStatement("drop table foo").execute();
        } catch (Exception e) {
            e.printStackTrace();
        }
        a.prepareStatement("create table foo(a int not null)").executeUpdate();
        a.prepareStatement("insert into foo values (1);").executeUpdate();
    }

    private void flogCatalogs(final Driver driver) throws SQLException {
        final Connection conn =3D newConnection(driver);
        try {
            conn.setAutoCommit(false);
            Statement ps =3D conn.createStatement();
            String a =3D "create temp table bar";
            String b =3D " (a int not null); ";
            for (int f =3D 0; f < 128; f++) {
                StringBuilder sb =3D new StringBuilder();
                sb.append(a).append(f).append(b);
                ps.execute(sb.toString());
            }
            conn.commit();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            try {
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

    public static void main(String... args) throws SQLException,
            InterruptedException {
        Bug5269Test test =3D new Bug5269Test();
        test.test();
    }

}



On Jan 13, 2010, at 10:22 PM, Justin Pitts wrote:

> Sorry for the delay.
>=20
> I am attempting to construct a JDBC test case that reproduces the problem=
.=20
>=20
> I have installed the patch and have not seen the crash since.
>=20
> On Jan 13, 2010, at 11:58 AM, Tom Lane wrote:
>=20