/*

 * Copyright (c) 2015, 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

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 */

import java.io.IOException;

import java.net.ServerSocket;

import java.net.URI;

import java.time.Duration;

import java.util.concurrent.CompletableFuture;

import java.util.concurrent.ExecutorService;

import java.util.concurrent.Executors;

import java.util.concurrent.LinkedBlockingQueue;

import static java.lang.System.out;

/**

 * @test

 * @bug 8178147

 * @summary Ensures that small timeouts do not cause hangs due to race conditions

 */

// To enable logging use. Not enabled by default as it changes the dynamics

// of the test.

// @run main/othervm -Djdk.httpclient.HttpClient.log=all,frames:all SmallTimeout

public class SmallTimeout {

    static int[] TIMEOUTS = {2, 1, 3, 2, 100, 1};

    // A queue for placing timed out requests so that their order can be checked.

    static LinkedBlockingQueue<HttpResult> queue = new LinkedBlockingQueue<>();

    static final class HttpResult {

         final HttpRequest request;

         final Throwable   failed;

         HttpResult(HttpRequest request, Throwable   failed) {

             this.request = request;

             this.failed = failed;

         }

         static HttpResult of(HttpRequest request) {

             return new HttpResult(request, null);

         }

         static HttpResult of(HttpRequest request, Throwable t) {

             return new HttpResult(request, t);

         }

    }

    static volatile boolean error;

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

        HttpClient client = HttpClient.newHttpClient();

        try (ServerSocket ss = new ServerSocket(0, 20)) {

            int port = ss.getLocalPort();

            URI uri = new URI("http://127.0.0.1:" + port + "/");

            HttpRequest[] requests = new HttpRequest[TIMEOUTS.length];

            out.println("--- TESTING Async");

            for (int i = 0; i < TIMEOUTS.length; i++) {

                requests[i] = HttpRequest.newBuilder(uri)

                                         .timeout(Duration.ofMillis(TIMEOUTS[i]))

                                         .GET()

                                         .build();

                final HttpRequest req = requests[i];

                CompletableFuture<HttpResponse<Object>> response = client

                    .sendAsync(req, replace(null))

                    .whenComplete((HttpResponse<Object> r, Throwable t) -> {

                        Throwable cause = null;

                        if (r != null) {

                            out.println("Unexpected response: " + r);

                            cause = new RuntimeException("Unexpected response");

                            error = true;

                        }

                        if (t != null) {

                            if (!(t.getCause() instanceof HttpTimeoutException)) {

                                out.println("Wrong exception type:" + t.toString());

                                Throwable c = t.getCause() == null ? t : t.getCause();

                                c.printStackTrace();

                                cause = c;

                                error = true;

                            } else {

                                out.println("Caught expected timeout: " + t.getCause());

                            }

                        }

                        if (t == null && r == null) {

                            out.println("Both response and throwable are null!");

                            cause = new RuntimeException("Both response and throwable are null!");

                            error = true;

                        }

                        queue.add(HttpResult.of(req,cause));

                    });

            }

            System.out.println("All requests submitted. Waiting ...");

            checkReturn(requests);

            if (error)

                throw new RuntimeException("Failed. Check output");

            // Repeat blocking in separate threads. Use queue to wait.

            out.println("--- TESTING Sync");

            // For running blocking response tasks

            ExecutorService executor = Executors.newCachedThreadPool();

            for (int i = 0; i < TIMEOUTS.length; i++) {

                requests[i] = HttpRequest.newBuilder(uri)

                                         .timeout(Duration.ofMillis(TIMEOUTS[i]))

                                         .GET()

                                         .build();

                final HttpRequest req = requests[i];

                executor.execute(() -> {

                    Throwable cause = null;

                    try {

                        client.send(req, replace(null));

                    } catch (HttpTimeoutException e) {

                        out.println("Caught expected timeout: " + e);

                    } catch (Throwable ee) {

                        Throwable c = ee.getCause() == null ? ee : ee.getCause();

                        c.printStackTrace();

                        cause = c;

                        error = true;

                    } finally {

                        queue.offer(HttpResult.of(req, cause));

                    }

                });

            }

            System.out.println("All requests submitted. Waiting ...");

            checkReturn(requests);

            executor.shutdownNow();

            if (error)

                throw new RuntimeException("Failed. Check output");

        }

    }

    static void checkReturn(HttpRequest[] requests) throws InterruptedException {

        // wait for exceptions and check order

        boolean ok = true;

        for (int j = 0; j < TIMEOUTS.length; j++) {

            HttpResult res = queue.take();

            HttpRequest req = res.request;

            out.println("Got request from queue " + req + ", order: " + getRequest(req, requests)

                         + (res.failed == null ? "" : " failed: " + res.failed));

            ok = ok && res.failed == null;

        }

        out.println("Return " + (ok ? "ok" : "nok"));

    }

    /** Returns the index of the request in the array. */

    static String getRequest(HttpRequest req, HttpRequest[] requests) {

        for (int i=0; i<requests.length; i++) {

            if (req == requests[i]) {

                return "r" + i;

            }

        }

        throw new AssertionError("Unknown request: " + req);

    }

}