无论CyclicBarrier如何,一个线程都会过早停止

时间:2011-02-11 01:51:51

标签: java multithreading socketchannel cyclicbarrier

我知道以下代码可能看起来很粗俗,但我是这些东西的新手,只是尝试了一切以使其工作..

问题:即使我使用(可能以错误的方式)一个CyclicBarrier,一个 - 似乎总是相同 - 线程停止太快并打印出他的向量,留下11个中的1个“传入连接“消息缺席。我的循环的最后一次迭代可能有一些非常严重的错误,但我似乎无法找到究竟是什么......现在程序只是循环等待处理最后一次连接。

public class VectorClockClient implements Runnable {
/*
 * Attributes
 */

/*
 * The client number is store to provide fast
 * array access when, for example, a thread's own
 * clock simply needs to be incremented.
 */
private int clientNumber;
private File configFile, inputFile;
int[] vectorClock;

/*
 * Constructor
 * @param
 * - File config
 * - int line
 * - File input
 * - int clients
 */
public VectorClockClient(File config, int line, File input, int clients) {
    /*
     * Make sure that File handles aren't null and that
     * the line number is valid.
     */
    if (config != null && line >= 0 && input != null) {
        configFile = config;
        inputFile = input;
        clientNumber = line;
        /*
         * Set the array size to the number of lines found in the
         * config file and initialize with zero values.
         */
        vectorClock = new int[clients];
        for (int i = 0; i < vectorClock.length; i++) {
            vectorClock[i] = 0;
        }
    }
}

private int parsePort() {
    int returnable = 0;
    try {
        FileInputStream fstream = new FileInputStream(configFile.getName());
        DataInputStream in = new DataInputStream(fstream);
        BufferedReader br = new BufferedReader(new InputStreamReader(in));
        String strLine = "";
        for (int i = 0; i < clientNumber + 1; i++) {
            strLine = br.readLine();
        }
        String[] tokens = strLine.split(" ");
        returnable = Integer.parseInt(tokens[1]);
    }
    catch (Exception e) {
        e.printStackTrace();
    }
    System.out.println("[" + clientNumber + "] returned with " + returnable + ".");
    return returnable;
}

private int parsePort(int client) {
    int returnable = 0;
    try {
        FileInputStream fstream = new FileInputStream(configFile.getName());
        DataInputStream in = new DataInputStream(fstream);
        BufferedReader br = new BufferedReader(new InputStreamReader(in));
        String strLine = "";
        for (int i = 0; i < client; i++) {
            strLine = br.readLine();
        }
        String[] tokens = strLine.split(" ");
        returnable = Integer.parseInt(tokens[1]);
    }
    catch (Exception e) {
        e.printStackTrace();
    }
    return returnable;
}

private int parseAction(String s) {
    int returnable = -1;
    try {
        FileInputStream fstream = new FileInputStream(configFile.getName());
        DataInputStream in = new DataInputStream(fstream);
        BufferedReader br = new BufferedReader(new InputStreamReader(in));
        String[] tokens = s.split(" ");
        if (!(Integer.parseInt(tokens[0]) == this.clientNumber + 1)) {
            return -1;
        }
        else {
            if (tokens[1].equals("L")) {
                vectorClock[clientNumber] += Integer.parseInt(tokens[2]);
            }
            else {
                returnable = Integer.parseInt(tokens[2]);
            }
        }
    }
    catch (Exception e) {
        e.printStackTrace();
    }
    return returnable;
}

/*
 * Do the actual work.
 */
public void run() {
    try {
        InitClients.barrier.await();
    }
    catch (Exception e) {
        System.out.println(e);
    }
    int port = parsePort();
    String hostname = "localhost";
    String strLine;
    ServerSocketChannel ssc;
    SocketChannel sc;
    FileInputStream fstream;
    DataInputStream in;
    BufferedReader br;
    boolean eof = false;
    try {
        ssc = ServerSocketChannel.open();
        ssc.socket().bind(new InetSocketAddress(hostname, port));
        ssc.configureBlocking(false);
        fstream = new FileInputStream("input_vector.txt");
        in = new DataInputStream(fstream);
        br = new BufferedReader(new InputStreamReader(in));

        try {
            InitClients.barrier.await();
        }
        catch (Exception e) {
            System.out.println(e);
        }

        while (true && (eof == false)) {
            sc = ssc.accept();

            if (sc == null) {
                if ((strLine = br.readLine()) != null) {
                    int result = parseAction(strLine);
                    if (result >= 0) {
                        //System.out.println("[" + (clientNumber + 1)
                        //+ "] Send a message to " + result + ".");
                        try {
                            SocketChannel client = SocketChannel.open();
                            client.configureBlocking(true);
                            client.connect(
                                    new InetSocketAddress("localhost",
                                    parsePort(result)));
                            //ByteBuffer buf = ByteBuffer.allocateDirect(32);
                            //buf.put((byte)0xFF);
                            //buf.flip();
                            //vectorClock[clientNumber] += 1;
                            //int numBytesWritten = client.write(buf);
                            String obj = Integer.toString(clientNumber+1);
                            ObjectOutputStream oos = new 
                                    ObjectOutputStream(
                                    client.socket().getOutputStream());
                            oos.writeObject(obj);
                            oos.close();
                        }
                        catch (Exception e) {
                            e.printStackTrace();
                        }
                    }
                }
                else {
                    eof = true;
                }
            }
            else {
                ObjectInputStream ois = new 
                        ObjectInputStream(sc.socket().getInputStream());
                String clientNumberString = (String)ois.readObject();
                System.out.println("At {Client[" + (clientNumber + 1)
                        + "]}Incoming connection from: "
                        + sc.socket().getRemoteSocketAddress()
                        + " from {Client[" + clientNumberString + "]}");
                sc.close();
            }
            try {
                InitClients.barrier.await();
            }
            catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
    catch (Exception e) {
        e.printStackTrace();
    }
    printVector();
}

private void printVector() {
    System.out.print("{Client[" + (clientNumber + 1) + "]}{");
    for (int i = 0; i < vectorClock.length; i++) {
        System.out.print(vectorClock[i] + "\t");
    }
    System.out.println("}");
}

}
为了澄清,这里是使用的文件的格式。 Config包含作为线程的客户端使用的主机名和端口,输入文件的行表示“此客户端向该客户端发送消息”或“此客户端将其逻辑时钟递增一些常量值”。

1 M 2(M表示发送信息)
2 M 3
3 M 4
2 L 7(L表示递增时钟)
2 M 1
 ...
127.0.0.1 9000
127.0.0.1 9001
127.0.0.1 9002
127.0.0.1 9003
    ...

1 个答案:

答案 0 :(得分:0)

我会看一下与期望传入套接字连接相关的逻辑。从您的问题看起来您期望一定数量的传入套接字连接(可能是每个传出消息后的传入连接?)。由于您在传入套接字上使用非阻塞I / O,因此while语句始终可以在建立传入套接字之前循环。因此,线程将能够继续并从文件中读取下一行而不接收连接。由于在到达文件末尾时达到了结束状态,因此可能会错过传入的套接字连接。

我会添加一些简单的打印输出,当您从文件中读取,发送消息和接收传入连接时显示。这应该快速告诉您特定线程是否缺少预期的传入连接。如果问题是由于非阻塞I / O引起的,那么当您期望传入套接字或实现一个跟踪您期望的传入套接字数量的控件时,您可能需要禁用非阻塞I / O.并一直持续到达到目标。

希望这有帮助。