simplethread.java

derby database source code.good for you.

/*

   Derby - Class org.apache.derbyTesting.functionTests.tests.lang.simpleThread

   Copyright 1999, 2004 The Apache Software Foundation or its licensors, as applicable.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.

 */

package org.apache.derbyTesting.functionTests.tests.lang;

import java.sql.Connection;
import java.sql.Statement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.DriverManager;
import org.apache.derby.tools.ij;

/*
	This is from a bug found by a beta customer.
 */
public class simpleThread implements Runnable {

        private static Connection _connection = null;
        private static boolean _inUse = false;
        private static Object _lock = new Object();

        private long _wait = 0;
        private long _myCount = 0;
        private static int _count = 0;
        private synchronized static int getCount() { return(_count++); }
        private String _query;

        public simpleThread( String query, long waitTime) {
                _wait = waitTime;
                _myCount = getCount();
                _query = query;
                new Thread(this).start();
        }

        public void run() {
				int rows = 0;
				boolean caught = false;
                try {
                        Thread.currentThread().sleep(_wait);
                        Connection conn = GetConnection();
                        Statement stmt = conn.createStatement();
                        String query = _query;
                        ResultSet rs = stmt.executeQuery( query );
                        ResultSetMetaData rsmd = rs.getMetaData();
                        //int cols = rsmd.getColumnCount();
                        while(rs.next()) {
							rows++;
                                //System.out.print(_myCount + ":");
                                //for( int x=0;x<cols;x++) {
                                 //       String s = rs.getString(x+1);
                                  //      if( x > 0) System.out.print(",");
                                   //     System.out.print(s);
                                //}
                                //System.out.println();
                        }
                        stmt.close();
                        ReturnConnection(conn);
                } catch (Exception ex) {
					// we expect some threads to get exceptions
					caught = true;
                }
				if (rows == 3 || caught)
				{
					//System.out.println("This thread's okay!");
			    }
				else
				{
					System.out.println("FAIL: thread "+_myCount+" only got "+rows+" rows and caught was "+caught);
		        }
        }


        public simpleThread(String argv[]) throws Exception {
            
			ij.getPropertyArg(argv);
			_connection = ij.startJBMS();

			Connection conn = GetConnection();

            Statement stmt = conn.createStatement();

            stmt.execute("create table people(name varchar(255), address varchar(255), phone varchar(64))");
            stmt.execute("insert into people VALUES ('mike', 'mikes address', '123-456-7890')");
            stmt.execute("insert into people VALUES ('adam', 'adams address', '123-456-1234')");
            stmt.execute("insert into people VALUES ('steve', 'steves address', '123-456-4321')");
            stmt.close();

            ReturnConnection(conn);

            String query = "SELECT * from people ORDER by name";

            try {
                String[] retval = new String[4];
                new simpleThread(query,0);
                new simpleThread(query,10000);
                new simpleThread(query,10100);
                new simpleThread(query,20000);
            } catch (Exception ex) {
                System.err.println(ex.toString() );
            }
        }

        public static Connection GetConnection() {
                synchronized(_lock) {
                        _inUse = true;
                }
                return _connection;
        }
        public static void ReturnConnection(Connection c) {
                synchronized(_lock) {
                        _inUse = false;
                        _lock.notifyAll();
                }
        }
}