/*

 * Copyright (c) 2003, 2017, 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

 * @bug 4776783 4778091 4778099

 * @summary Check various properties of key and selected-key sets

 *

 * @run main KeySets

 */

import java.io.*;

import java.nio.channels.*;

import java.util.*;

public class KeySets {

    static abstract class Catch {

        abstract void go() throws Exception;

        Catch(Class xc) throws Exception {

            try {

                go();

            } catch (Exception x) {

                if (xc.isInstance(x))

                    return;

                throw new Exception("Wrong exception", x);

            }

            throw new Exception("Not thrown as expected: " + xc.getName());

        }

    }

    // 4776783: Closing a selector should make key sets inaccessible

    static void testClose() throws Exception {

        final Selector sel = Selector.open();

        sel.keys();

        sel.selectedKeys();

        sel.close();

        new Catch(ClosedSelectorException.class) {

                void go() throws Exception {

                    sel.keys();

                }};

        new Catch(ClosedSelectorException.class) {

                void go() throws Exception {

                    sel.selectedKeys();

                }};

    }

    static void testNoAddition(final Set s) throws Exception {

        new Catch(UnsupportedOperationException.class) {

                void go() throws Exception {

                    s.add(new Object());

                }};

        new Catch(UnsupportedOperationException.class) {

                void go() throws Exception {

                    ArrayList al = new ArrayList();

                    al.add(new Object());

                    s.addAll(al);

                }};

    }

    static interface Adder {

        void add() throws IOException;

    }

    static void testNoRemoval(final Set s, final Adder adder)

        throws Exception

    {

        new Catch(UnsupportedOperationException.class) {

                void go() throws Exception {

                    adder.add();

                    s.clear();

                }};

        new Catch(UnsupportedOperationException.class) {

                void go() throws Exception {

                    adder.add();

                    Iterator i = s.iterator();

                    i.next();

                    i.remove();

                }};

        new Catch(UnsupportedOperationException.class) {

                void go() throws Exception {

                    adder.add();

                    s.remove(s.iterator().next());

                }};

        new Catch(UnsupportedOperationException.class) {

                void go() throws Exception {

                    adder.add();

                    HashSet hs = new HashSet();

                    hs.addAll(s);

                    s.removeAll(hs);

                }};

        new Catch(UnsupportedOperationException.class) {

                void go() throws Exception {

                    adder.add();

                    s.retainAll(Collections.EMPTY_SET);

                }};

    }

    static SelectionKey reg(Selector sel) throws IOException {

        DatagramChannel dc = DatagramChannel.open();

        dc.configureBlocking(false);

        return dc.register(sel, SelectionKey.OP_WRITE);

    }

    static void testMutability() throws Exception {

        final Selector sel = Selector.open();

        // 4778091: Selector.keys() should be immutable

        testNoRemoval(sel.keys(), new Adder() {

                public void add() throws IOException {

                    reg(sel);

                }

            });

        testNoAddition(sel.keys());

        // 4778099: Selector.selectedKeys() should allow removal but not addition

        sel.select();

        testNoAddition(sel.selectedKeys());

        SelectionKey sk = reg(sel);

        sel.select();

        int n = sel.selectedKeys().size();

        sel.selectedKeys().remove(sk);

        if (sel.selectedKeys().size() != n - 1)

            throw new Exception("remove failed");

        HashSet hs = new HashSet();

        hs.add(reg(sel));

        sel.select();

        sel.selectedKeys().retainAll(hs);

        if (sel.selectedKeys().isEmpty())

            throw new Exception("retainAll failed");

        sel.selectedKeys().removeAll(hs);

        if (!sel.selectedKeys().isEmpty())

            throw new Exception("removeAll failed");

        hs.clear();

        hs.add(reg(sel));

        sel.select();

        sel.selectedKeys().clear();

        if (!sel.selectedKeys().isEmpty())

            throw new Exception("clear failed");

    }

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

        testClose();

        testMutability();

    }

}