/*
 * Copyright (c) 2005, 2023, 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.
 */

/*
 * @test
 * @bug 5045306 6356004 6993490 8255124
 * @library /test/lib
 * @run main/othervm B5045306
 * @summary Http keep-alive implementation is not efficient
 */

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.management.ManagementFactory;
import java.lang.management.ThreadInfo;
import java.lang.management.ThreadMXBean;
import java.net.HttpURLConnection;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.Proxy;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Executors;

import com.sun.net.httpserver.HttpExchange;
import com.sun.net.httpserver.HttpHandler;
import com.sun.net.httpserver.HttpServer;

/* Part 1:
 * The http client makes a connection to a URL whos content contains a lot of
 * data, more than can fit in the socket buffer. The client only reads
 * 1 byte of the data from the InputStream leaving behind more data than can
 * fit in the socket buffer. The client then makes a second call to the http
 * server. If the connection port used by the client is the same as for the
 * first call then that means that the connection is being reused.
 *
 * Part 2:
 * Test buggy webserver that sends less data than it specifies in its
 * Content-length header.
 */

public class B5045306 {
    static HttpServer server;

    public static void main(String[] args) {
        startHttpServer();
        clientHttpCalls();
    }

    public static void startHttpServer() {
        try {
            server = HttpServer.create(new InetSocketAddress(InetAddress.getLocalHost(), 0), 10, "/", new SimpleHttpTransactionHandler());
            server.setExecutor(Executors.newSingleThreadExecutor());
            server.start();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static void clientHttpCalls() {
        List<Throwable> uncaught = new ArrayList<>();
        Thread.setDefaultUncaughtExceptionHandler((t, ex) -> {
            uncaught.add(ex);
        });
        try {
            System.out.println("http server listen on: " + server.getAddress().getPort());
            String hostAddr =  InetAddress.getLocalHost().getHostAddress();
            if (hostAddr.indexOf(':') > -1) hostAddr = "[" + hostAddr + "]";
            String baseURLStr = "http://" + hostAddr + ":" + server.getAddress().getPort() + "/";

            URL bigDataURL = new URL (baseURLStr + "firstCall");
            URL smallDataURL = new URL (baseURLStr + "secondCall");

            HttpURLConnection uc = (HttpURLConnection)bigDataURL.openConnection(Proxy.NO_PROXY);

            //Only read 1 byte of response data and close the stream
            InputStream is = uc.getInputStream();
            byte[] ba = new byte[1];
            is.read(ba);
            is.close();

            // Allow the KeepAliveStreamCleaner thread to read the data left behind and cache the connection.
            try { Thread.sleep(2000); } catch (Exception e) {}

            uc = (HttpURLConnection)smallDataURL.openConnection(Proxy.NO_PROXY);
            uc.getResponseCode();

            if (SimpleHttpTransactionHandler.failed)
                throw new RuntimeException("Failed: Initial Keep Alive Connection is not being reused");

            // Part 2
            URL part2Url = new URL (baseURLStr + "part2");
            uc = (HttpURLConnection)part2Url.openConnection(Proxy.NO_PROXY);
            is = uc.getInputStream();
            is.close();

            // Allow the KeepAliveStreamCleaner thread to try and read the data left behind and cache the connection.
            try { Thread.sleep(2000); } catch (Exception e) {}

            ThreadMXBean threadMXBean = ManagementFactory.getThreadMXBean();
            if (threadMXBean.isThreadCpuTimeSupported()) {
                long[] threads = threadMXBean.getAllThreadIds();
                ThreadInfo[] threadInfo = threadMXBean.getThreadInfo(threads);
                for (int i=0; i<threadInfo.length; i++) {
                    if (threadInfo[i].getThreadName().equals("Keep-Alive-SocketCleaner"))  {
                        System.out.println("Found Keep-Alive-SocketCleaner thread");
                        long threadID = threadInfo[i].getThreadId();
                        long before = threadMXBean.getThreadCpuTime(threadID);
                        try { Thread.sleep(2000); } catch (Exception e) {}
                        long after = threadMXBean.getThreadCpuTime(threadID);

                        if (before ==-1 || after == -1)
                            break;  // thread has died, OK

                        // if Keep-Alive-SocketCleaner consumes more than 50% of cpu then we
                        // can assume a recursive loop.
                        long total = after - before;
                        if (total >= 1000000000)  // 1 second, or 1 billion nanoseconds
                            throw new RuntimeException("Failed: possible recursive loop in Keep-Alive-SocketCleaner");
                    }
                }
            }

        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            server.stop(1);
        }
        if (!uncaught.isEmpty()) {
            throw new RuntimeException("Unhandled exception:", uncaught.get(0));
        }
    }
}

class SimpleHttpTransactionHandler implements HttpHandler
{
    static volatile boolean failed = false;

    // Need to have enough data here that is too large for the socket buffer to hold.
    // Also http.KeepAlive.remainingData must be greater than this value, default is 256K.
    static final int RESPONSE_DATA_LENGTH = 128 * 1024;

    int port1;

    public void handle(HttpExchange trans) {
        try {
            String path = trans.getRequestURI().getPath();
            if (path.equals("/firstCall")) {
                port1 = trans.getRemoteAddress().getPort();
                System.out.println("First connection on client port = " + port1);

                byte[] responseBody = new byte[RESPONSE_DATA_LENGTH];
                for (int i=0; i<responseBody.length; i++)
                    responseBody[i] = 0x41;
                trans.sendResponseHeaders(200, responseBody.length);
                try (OutputStream os = trans.getResponseBody()) {
                    os.write(responseBody);
                }
            } else if (path.equals("/secondCall")) {
                int port2 = trans.getRemoteAddress().getPort();
                System.out.println("Second connection on client port = " + port2);

                if (port1 != port2)
                    failed = true;

                 /* Force the server to not respond for more that the timeout
                  * set by the keepalive cleaner (5000 millis). This ensures the
                  * timeout is correctly resets the default read timeout,
                  * infinity. See 6993490. */
                System.out.println("server sleeping...");
                try {Thread.sleep(6000); } catch (InterruptedException e) {}
                trans.sendResponseHeaders(200, -1);
            } else if(path.equals("/part2")) {
                System.out.println("Call to /part2");
                byte[] responseBody = new byte[RESPONSE_DATA_LENGTH];
                for (int i=0; i<responseBody.length; i++)
                    responseBody[i] = 0x41;
                // override the Content-length header to be greater than the actual response body
                trans.sendResponseHeaders(200, responseBody.length+1);
                OutputStream os = trans.getResponseBody();
                os.write(responseBody);
                // now close the socket
                // closing the stream here would throw; close the exchange instead
                trans.close();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}