/*
 * 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
 * @bug 8201315
 * @summary Test that channels can be registered, interest ops can changed,
 *          and keys cancelled while a selection operation is in progress.
 */

import java.io.IOException;
import java.nio.channels.Pipe;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;

public class RegisterDuringSelect {
    static abstract class Select {
        Selector sel;
        Pipe p;
        Pipe.SourceChannel sc;
        SelectionKey key;
        Thread t;

        Select() throws Exception {
            sel = Selector.open();
            p = Pipe.open();
            sc = p.source();
            sc.configureBlocking(false);
        }
        Runnable selectF(Selector sel) {
            return new Runnable() {
                @Override
                public void run() {
                    try {
                        sel.select();
                    } catch (IOException ex) {
                        throw new RuntimeException(ex);
                    }
                }
            };
        }
        void test() throws Exception {
            try {
                t = new Thread(selectF(sel));
                t.start();
                key = sc.register(sel, SelectionKey.OP_READ);
                realTest();
            } finally {
                sel.close();
                p.source().close();
                p.sink().close();
            }
        }
        abstract void realTest() throws Exception;
    }

    /**
     * Invoke register, interestOps, and cancel concurrently with a thread
     * doing a selection operation
     */
    public static void main(String args[]) throws Exception {
        new Select() {
            @Override
            void realTest() {
                System.out.println("register ...");
                sel.wakeup();
                if (!sel.keys().contains(key))
                    throw new RuntimeException("key not in key set");
            }
        }.test();
        new Select() {
            @Override
            void realTest() {
                System.out.println("interestOps ...");
                key.interestOps(0);
                sel.wakeup();
                if (key.interestOps() != 0)
                    throw new RuntimeException("interested ops not cleared");
            }
        }.test();
        new Select() {
            @Override
            void realTest() throws Exception {
                System.out.println("cancel ...");
                key.cancel();
                sel.wakeup();
                t.join();
                if (sel.keys().contains(key))
                    throw new RuntimeException("key not removed from key set");
            }
        }.test();
    }
}