Lock.java

class Lock { 
    public static void main( String ... args ) { 
        StringBuffer buffer = new StringBuffer();
        //synchronized(buffer) { 
            for ( int i = 0 ; i < Integer.MAX_VALUE / 16 ; i++ ) { 
                buffer.append( i );
                buffer.delete(0, buffer.length() -1 );
            }
        //}
    }
}