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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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 java.io.IOException;
import java.net.ServerSocket;
import java.net.URI;
import jdk.incubator.http.HttpClient;
import jdk.incubator.http.HttpRequest;
import jdk.incubator.http.HttpResponse;
import jdk.incubator.http.HttpTimeoutException;
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;
import static jdk.incubator.http.HttpResponse.BodyHandler.discard;

/**
 * @test
 * @bug 8178147
 * @summary Ensures that small timeouts do not cause hangs due to race conditions
 * @run main/othervm SmallTimeout
 */

// 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<HttpRequest> queue = new LinkedBlockingQueue<>();

    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, discard(null))
                    .whenComplete((HttpResponse<Object> r, Throwable t) -> {
                        if (r != null) {
                            out.println("Unexpected response: " + r);
                            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();
                                error = true;
                            } else {
                                out.println("Caught expected timeout: " + t.getCause());
                            }
                        }
                        if (t == null && r == null) {
                            out.println("Both response and throwable are null!");
                            error = true;
                        }
                        queue.add(req);
                    });
            }
            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(() -> {
                    try {
                        client.send(req, discard(null));
                    } catch (HttpTimeoutException e) {
                        out.println("Caught expected timeout: " + e);
                        queue.offer(req);
                    } catch (IOException | InterruptedException ee) {
                        Throwable c = ee.getCause() == null ? ee : ee.getCause();
                        c.printStackTrace();
                        error = true;
                    }
                });
            }
            System.out.println("All requests submitted. Waiting ...");

            checkReturn(requests);

            executor.shutdownNow();

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

        } finally {
            ((ExecutorService) client.executor()).shutdownNow();
        }
    }

    static void checkReturn(HttpRequest[] requests) throws InterruptedException {
        // wait for exceptions and check order
        for (int j = 0; j < TIMEOUTS.length; j++) {
            HttpRequest req = queue.take();
            out.println("Got request from queue " + req + ", order: " + getRequest(req, requests));
        }
        out.println("Return ok");
    }

    /** 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);
    }
}