/*

 * Copyright (c) 2011 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

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 */

/*

 * Portions Copyright (c) 2011 IBM Corporation

 */

/*

 * @test

 * @bug 7014637

 * @summary EnumSet's iterator.remove() can be resilient to set's modification.

 * @author Neil Richards <neil.richards@ngmr.net>, <neil_richards@uk.ibm.com>

 */

import java.util.EnumSet;

import java.util.Iterator;

import java.util.Set;

public class LargeEnumIteratorRemoveResilience {

    // enum with more than 64 values

    private static enum LargeEnum {

        e00, e01, e02, e03, e04, e05, e06, e07,

        e08, e09, e0A, e0B, e0C, e0D, e0E, e0F,

        e10, e11, e12, e13, e14, e15, e16, e17,

        e18, e19, e1A, e1B, e1C, e1D, e1E, e1F,

        e20, e21, e22, e23, e24, e25, e26, e27,

        e28, e29, e2A, e2B, e2C, e2D, e2E, e2F,

        e30, e31, e32, e33, e34, e35, e36, e37,

        e38, e39, e3A, e3B, e3C, e3D, e3E, e3F,

        e40, e41, e42, e43, e44, e45, e46, e47,

        e48, e49, e4A, e4B, e4C, e4D, e4E, e4F,

    }

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

        final Set<LargeEnum> set = EnumSet.noneOf(LargeEnum.class);

        set.add(LargeEnum.e2D);

        set.add(LargeEnum.e42);

        final Iterator<LargeEnum> iterator = set.iterator();

        int size = set.size();

        LargeEnum element = iterator.next();

        iterator.remove();

        checkSetAfterRemoval(set, size, element);

        size = set.size();

        element = iterator.next();

        set.remove(element);

        checkSetAfterRemoval(set, size, element);

        // The Java API declares that the behaviour here - to call

        // iterator.remove() after the underlying collection has been

        // modified - is "unspecified".

        // However, in the case of iterators for EnumSet, it is easy to

        // implement their remove() operation such that the set is

        // unmodified if it is called for an element that has already been

        // removed from the set - this being the naturally "resilient"

        // behaviour.

        iterator.remove();

        checkSetAfterRemoval(set, size, element);

    }

    private static void checkSetAfterRemoval(final Set<LargeEnum> set,

            final int origSize, final LargeEnum removedElement)

            throws Exception {

        if (set.size() != (origSize - 1)) {

            throw new Exception("Test FAILED: Unexpected set size after removal; expected '" + (origSize - 1) + "' but found '" + set.size() + "'");

        }

        if (set.contains(removedElement)) {

            throw new Exception("Test FAILED: Element returned from iterator unexpectedly still in set after removal.");

        }

    }

}