/*

 * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

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 */

/* @test

 * @bug 4639943

 * @summary  Checks that Windows behavior matches Solaris for

 *           various read/select combinations.

 * @author kladko

 */

import java.nio.ByteBuffer;

import java.nio.channels.Selector;

import java.nio.channels.SelectionKey;

import java.nio.channels.SocketChannel;

public class SelectAfterRead {

    private static final int TIMEOUT = 1000;

    public static void main(String[] argv) throws Exception {

        // server: accept connection and write one byte

        try (ByteServer server = new ByteServer();

             SocketChannel sc = SocketChannel.open(server.address())) {

            server.acceptConnection();

            server.write(1);

            try (Selector sel = Selector.open()) {

                sc.read(ByteBuffer.allocate(1));

                sc.configureBlocking(false);

                sc.register(sel, SelectionKey.OP_READ);

                // previously on Windows select would select channel here, although there was

                // nothing to read

                if (sel.selectNow() != 0)

                    throw new Exception("Select returned nonzero value");

            }

        }

        // Now we will test a two reads combination

        // server: accept connection and write two bytes

        try (ByteServer server = new ByteServer();

             SocketChannel sc = SocketChannel.open(server.address())) {

            server.acceptConnection();

            server.write(2);

            try (Selector sel = Selector.open()) {

                sc.configureBlocking(false);

                sc.register(sel, SelectionKey.OP_READ);

                if (sel.select(TIMEOUT) != 1)

                    throw new Exception("One selected key expected");

                sel.selectedKeys().clear();

                // previously on Windows a channel would get selected only once

                if (sel.selectNow() != 1)

                    throw new Exception("One selected key expected");

                // Previously on Windows two consequent reads would cause select()

                // to select a channel, although there was nothing remaining to

                // read in the channel

                if (sc.read(ByteBuffer.allocate(1)) != 1)

                    throw new Exception("One byte expected");

                if (sc.read(ByteBuffer.allocate(1)) != 1)

                    throw new Exception("One byte expected");

                if (sel.selectNow() != 0)

                    throw new Exception("Select returned nonzero value");

            }

        }

    }

}