/*

 * Copyright (c) 2018, 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.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

/* @test

 * @run testng UpdateReadyOps

 * @summary Test that the ready set from a selection operation is bitwise-disjoined

 *     into a key's ready set when the key is already in the selected-key set

 */

import java.io.Closeable;

import java.io.IOException;

import java.net.InetAddress;

import java.net.InetSocketAddress;

import java.nio.ByteBuffer;

import java.nio.channels.SelectionKey;

import java.nio.channels.Selector;

import java.nio.channels.ServerSocketChannel;

import java.nio.channels.SocketChannel;

import org.testng.annotations.Test;

import static org.testng.Assert.*;

@Test

public class UpdateReadyOps {

    /**

     * Test that OP_WRITE is preserved when updating the ready set of a key in

     * the selected-key set to add OP_READ.

     */

    public void testOpWritePreserved() throws Exception {

        try (ConnectionPair pair = new ConnectionPair();

             Selector sel = Selector.open()) {

            SocketChannel sc1 = pair.channel1();

            SocketChannel sc2 = pair.channel2();

            sc1.configureBlocking(false);

            SelectionKey key = sc1.register(sel, SelectionKey.OP_WRITE);

            int updated = sel.select();

            assertTrue(updated == 1);

            assertTrue(sel.selectedKeys().contains(key));

            assertFalse(key.isReadable());

            assertTrue(key.isWritable());

            // select again, should be no updates

            updated = sel.select();

            assertTrue(updated == 0);

            assertTrue(sel.selectedKeys().contains(key));

            assertFalse(key.isReadable());

            assertTrue(key.isWritable());

            // write some bytes

            sc2.write(helloMessage());

            // change interest ops to OP_READ, do a selection operation, and

            // check that the ready set becomes OP_READ|OP_WRITE.

            key.interestOps(SelectionKey.OP_READ);

            updated = sel.select();

            assertTrue(updated == 1);

            assertTrue(sel.selectedKeys().size() == 1);

            assertTrue(key.isReadable());

            assertTrue(key.isWritable());

            assertTrue(key.readyOps() == (SelectionKey.OP_READ|SelectionKey.OP_WRITE));

            // select again, should be no updates

            updated = sel.select();

            assertTrue(updated == 0);

            assertTrue(sel.selectedKeys().size() == 1);

            assertTrue(key.isReadable());

            assertTrue(key.isWritable());

        }

    }

    /**

     * Test that OP_READ is preserved when updating the ready set of a key in

     * the selected-key set to add OP_WRITE.

     */

    public void testOpReadPreserved() throws Exception {

        try (ConnectionPair pair = new ConnectionPair();

             Selector sel = Selector.open()) {

            SocketChannel sc1 = pair.channel1();

            SocketChannel sc2 = pair.channel2();

            sc1.configureBlocking(false);

            SelectionKey key = sc1.register(sel, SelectionKey.OP_READ);

            // write some bytes

            sc2.write(helloMessage());

            int updated = sel.select();

            assertTrue(updated == 1);

            assertTrue(sel.selectedKeys().size() == 1);

            assertTrue(sel.selectedKeys().contains(key));

            assertTrue(key.isReadable());

            assertFalse(key.isWritable());

            // select again, should be no updates

            updated = sel.select();

            assertTrue(updated == 0);

            assertTrue(sel.selectedKeys().contains(key));

            assertTrue(key.isReadable());

            assertFalse(key.isWritable());

            key.interestOps(SelectionKey.OP_WRITE);

            updated = sel.select();

            assertTrue(updated == 1);

            assertTrue(sel.selectedKeys().size() == 1);

            assertTrue(sel.selectedKeys().contains(key));

            assertTrue(key.isReadable());

            assertTrue(key.isWritable());

            assertTrue(key.readyOps() == (SelectionKey.OP_READ|SelectionKey.OP_WRITE));

            // select again, should be no updates

            updated = sel.select();

            assertTrue(updated == 0);

            assertTrue(sel.selectedKeys().size() == 1);

            assertTrue(key.isReadable());

            assertTrue(key.isWritable());

        }

    }

    static class ConnectionPair implements Closeable {

        private final SocketChannel sc1;

        private final SocketChannel sc2;

        ConnectionPair() throws IOException {

            InetAddress lb = InetAddress.getLoopbackAddress();

            try (ServerSocketChannel ssc = ServerSocketChannel.open()) {

                ssc.bind(new InetSocketAddress(lb, 0));

                this.sc1 = SocketChannel.open(ssc.getLocalAddress());

                this.sc2 = ssc.accept();

            }

        }

        SocketChannel channel1() {

            return sc1;

        }

        SocketChannel channel2() {

            return sc2;

        }

        public void close() throws IOException {

            sc1.close();

            sc2.close();

        }

    }

    static ByteBuffer helloMessage() throws Exception {

        return ByteBuffer.wrap("hello".getBytes("UTF-8"));

    }

}