| /* |
| * 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 |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* |
| * 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 SmallEnumIteratorRemoveResilience { |
| // enum with less than 64 values |
| private static enum SmallEnum { e0, e1, e2 } |
| |
| public static void main(final String[] args) throws Exception { |
| final Set<SmallEnum> set = EnumSet.noneOf(SmallEnum.class); |
| |
| set.add(SmallEnum.e0); |
| set.add(SmallEnum.e1); |
| |
| final Iterator<SmallEnum> iterator = set.iterator(); |
| |
| int size = set.size(); |
| SmallEnum 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<SmallEnum> set, |
| final int origSize, final SmallEnum 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."); |
| } |
| } |
| } |