import java.util.List;

import java.util.Random;

import java.util.concurrent.Flow;

import java.util.stream.IntStream;

import java.time.Instant;

import java.time.temporal.ChronoUnit;

import jdk.incubator.http.internal.common.FlowTube;

 * @summary Verifies that the ConnectionPool correctly handle

 *          connection deadlines and purges the right connections

 *          from the cache.

 * @bug 8187044 8187111

        Random random = new Random();

        final int count = 20;

        Instant now = Instant.now().truncatedTo(ChronoUnit.SECONDS);

        int[] keepAlives = new int[count];

        HttpConnectionStub[] connections = new HttpConnectionStub[count];

        long purge = pool.purgeExpiredConnectionsAndReturnNextDeadline(now);

        long expected = 0;

        if (purge != expected) {

            throw new RuntimeException("Bad purge delay: " + purge

                                        + ", expected " + expected);

        expected = Long.MAX_VALUE;

        for (int i=0; i<count; i++) {

            keepAlives[i] = random.nextInt(10) * 10  + 10;

            connections[i] = new HttpConnectionStub(client, addr, proxy, true);

            System.out.println("Adding connection: " + now

                                + " keepAlive: " + keepAlives[i]

                                + " /" + connections[i]);

            pool.returnToPool(connections[i], now, keepAlives[i]);

            expected = Math.min(expected, keepAlives[i] * 1000);

            purge = pool.purgeExpiredConnectionsAndReturnNextDeadline(now);

            if (purge != expected) {

                throw new RuntimeException("Bad purge delay: " + purge

                                        + ", expected " + expected);

        int min = IntStream.of(keepAlives).min().getAsInt();

        int max = IntStream.of(keepAlives).max().getAsInt();

        int mean = (min + max)/2;

        System.out.println("min=" + min + ", max=" + max + ", mean=" + mean);

        purge = pool.purgeExpiredConnectionsAndReturnNextDeadline(now);

        System.out.println("first purge would be in " + purge + " ms");

        if (Math.abs(purge/1000 - min) > 0) {

            throw new RuntimeException("expected " + min + " got " + purge/1000);

        long opened = java.util.stream.Stream.of(connections)

                     .filter(HttpConnectionStub::connected).count();

        if (opened != count) {

            throw new RuntimeException("Opened: expected "

                                       + count + " got " + opened);

        purge = mean * 1000;

        System.out.println("start purging at " + purge + " ms");

        Instant next = now;

        do {

           System.out.println("next purge is in " + purge + " ms");

           next = next.plus(purge, ChronoUnit.MILLIS);

           purge = pool.purgeExpiredConnectionsAndReturnNextDeadline(next);

           long k = now.until(next, ChronoUnit.SECONDS);

           System.out.println("now is " + k + "s from start");

           for (int i=0; i<count; i++) {

               if (connections[i].connected() != (k < keepAlives[i])) {

                   throw new RuntimeException("Bad connection state for "

                             + i

                             + "\n\t connected=" + connections[i].connected()

                             + "\n\t keepAlive=" + keepAlives[i]

                             + "\n\t elapsed=" + k);

               }

           }

        } while (purge > 0);

        opened = java.util.stream.Stream.of(connections)

                     .filter(HttpConnectionStub::connected).count();

        if (opened != 0) {

           throw new RuntimeException("Closed: expected "

                                       + count + " got "

                                       + (count-opened));

    static class FlowTubeStub implements FlowTube {

        final HttpConnectionStub conn;

        FlowTubeStub(HttpConnectionStub conn) { this.conn = conn; }

        @Override

        public void onSubscribe(Flow.Subscription subscription) { }

        @Override public void onError(Throwable error) { error(); }

        @Override public void onComplete() { error(); }

        @Override public void onNext(List<ByteBuffer> item) { error();}

        @Override

        public void subscribe(Flow.Subscriber<? super List<ByteBuffer>> subscriber) {

        }

        @Override public boolean isFinished() { return conn.closed; }

    }

            this.flow = new FlowTubeStub(this);

        final InetSocketAddress proxy;

        final InetSocketAddress address;

        final boolean secured;

        final ConnectionPool.CacheKey key;

        final HttpClient client;

        final FlowTubeStub flow;

        volatile boolean closed;

        @Override boolean connected() {return !closed;}

        @Override

        public void close() {

            closed=true;

            System.out.println("closed: " + this);

        }

        @Override

        @Override public HttpPublisher publisher() {return error();}

        @Override public void flushAsync() throws IOException {error();}

        public void writeAsync(ByteBufferReference[] buffers) throws IOException {

        public void writeAsyncUnordered(ByteBufferReference[] buffers)

        @Override

        HttpConnection.DetachedConnectionChannel detachChannel() {

            return error();

        }

        @Override

        FlowTube getConnectionFlow() {return flow;}

        @Override public SSLParameters sslParameters() {return error();}

        @Override public Optional<Executor> executor() {return error();}

                HttpResponse.MultiSubscriber<U, T> multiSubscriber) {