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 * 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.

 *

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import jdk.internal.net.http.common.OperationTrackers;

import jdk.internal.net.http.common.OperationTrackers.Tracker;

import java.net.http.HttpClient;

import java.util.concurrent.ConcurrentLinkedQueue;

import java.util.stream.Collectors;

/**

 * A small helper class to help track clients which still

 * have pending operations at the end of a test.

 */

public class ReferenceTracker {

    private final ConcurrentLinkedQueue<Tracker> TRACKERS

            = new ConcurrentLinkedQueue<Tracker>();

    public static final ReferenceTracker INSTANCE

            = new ReferenceTracker();

    public HttpClient track(HttpClient client) {

        Tracker tracker = OperationTrackers.getTracker(client);

        assert tracker != null;

        TRACKERS.add(tracker);

        return client;

    }

    public long getTrackedClientCount() {

        return TRACKERS.size();

    }

    public StringBuilder diagnose(StringBuilder warnings) {

        for (Tracker tracker : TRACKERS) {

            checkOutstandingOperations(warnings, tracker);

        }

        return warnings;

    }

    public boolean hasOutstandingOperations() {

        return TRACKERS.stream().anyMatch(t -> t.getOutstandingOperations() > 0);

    }

    public long getOutstandingOperationsCount() {

        return TRACKERS.stream()

                .map(Tracker::getOutstandingOperations)

                .filter(n -> n > 0)

                .collect(Collectors.summingLong(n -> n));

    }

    public long getOutstandingClientCount() {

        return TRACKERS.stream()

                .map(Tracker::getOutstandingOperations)

                .filter(n -> n > 0)

                .count();

    }

    public AssertionError check(long graceDelayMs) {

        AssertionError fail = null;

        if (hasOutstandingOperations()) {

            try {

                Thread.sleep(graceDelayMs);

            } catch (InterruptedException x) {

                // OK

            }

            StringBuilder warnings = diagnose(new StringBuilder());

            addSummary(warnings);

            if (hasOutstandingOperations()) {

                fail = new AssertionError(warnings.toString());

            }

        } else {

            System.out.println("PASSED: No outstanding operations found in "

                    + getTrackedClientCount() + " clients");

        }

        return fail;

    }

    private void addSummary(StringBuilder warning) {

        long activeClients = getOutstandingClientCount();

        long operations = getOutstandingOperationsCount();

        long tracked = getTrackedClientCount();

        if (warning.length() > 0) warning.append("\n");

        int pos = warning.length();

        warning.append("Found ")

                .append(activeClients)

                .append(" client still active, with ")

                .append(operations)

                .append(" operations still pending out of ")

                .append(tracked)

                .append(" tracked clients.");

        System.out.println(warning.toString().substring(pos));

        System.err.println(warning.toString().substring(pos));

    }

    private static void checkOutstandingOperations(StringBuilder warning, Tracker tracker) {

        if (tracker.getOutstandingOperations() > 0) {

            if (warning.length() > 0) warning.append("\n");

            int pos = warning.length();

            warning.append("WARNING: tracker for " + tracker.getName() + " has outstanding operations:");

            warning.append("\n\tPending HTTP/1.1 operations: " + tracker.getOutstandingHttpOperations());

            warning.append("\n\tPending HTTP/2 streams: " + tracker.getOutstandingHttp2Streams());

            warning.append("\n\tPending WebSocket operations: " + tracker.getOutstandingWebSocketOperations());

            warning.append("\n\tTotal pending operations: " + tracker.getOutstandingOperations());

            warning.append("\n\tFacade referenced: " + tracker.isFacadeReferenced());

            System.out.println(warning.toString().substring(pos));

            System.err.println(warning.toString().substring(pos));

        }

    }

}