/*

 * Copyright (c) 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.

 */

package gc.concurrent_phase_control;

/*

 * Utility class that provides verification of expected behavior of

 * the Concurrent GC Phase Control WB API when the current GC supports

 * phase control.  The invoking test must provide WhiteBox access.

 */

import sun.hotspot.WhiteBox;

import java.util.Arrays;

import java.util.HashSet;

import java.util.List;

import java.util.Set;

public class CheckSupported {

    private static final WhiteBox WB = WhiteBox.getWhiteBox();

    private static Set<String> toSet(List<String> list, String which)

        throws Exception

    {

        Set<String> result = new HashSet<String>(list);

        if (result.size() < list.size()) {

            throw new RuntimeException(which + " phases contains duplicates");

        }

        return result;

    }

    private static void checkPhases(String[] expectedPhases) throws Exception {

        String[] actualPhases = WB.getConcurrentGCPhases();

        List<String> expectedList = Arrays.asList(expectedPhases);

        List<String> actualList = Arrays.asList(actualPhases);

        Set<String> expected = toSet(expectedList, "Expected");

        Set<String> actual = toSet(actualList, "Actual");

        expected.removeAll(actualList);

        actual.removeAll(expectedList);

        boolean match = true;

        if (!expected.isEmpty()) {

            match = false;

            System.out.println("Unexpected phases:");

            for (String s: expected) {

                System.out.println("  " + s);

            }

        }

        if (!actual.isEmpty()) {

            match = false;

            System.out.println("Expected but missing phases:");

            for (String s: actual) {

                System.out.println("  " + s);

            }

        }

        if (!match) {

            throw new RuntimeException("Mismatch between expected and actual phases");

        }

    }

    public static void check(String gcName, String[] phases) throws Exception {

        // Verify supported.

        if (!WB.supportsConcurrentGCPhaseControl()) {

            throw new RuntimeException(

                gcName + " unexpectedly missing phase control support");

        }

        checkPhases(phases);

        // Verify IllegalArgumentException thrown by request attempt

        // with unknown phase.

        boolean illegalArgumentThrown = false;

        try {

            WB.requestConcurrentGCPhase("UNKNOWN PHASE");

        } catch (IllegalArgumentException e) {

            // Expected.

            illegalArgumentThrown = true;

        } catch (Exception e) {

            throw new RuntimeException(

                gcName + ": Unexpected exception when requesting unknown phase: " + e.toString());

        }

        if (!illegalArgumentThrown) {

            throw new RuntimeException(

                gcName + ": No exception when requesting unknown phase");

        }

    }

}