如何在单个应用程序中正确使用 Qt 中的多个 QUdpSocket

Question

我创建了一个使用 UDP 协议的服务器和客户端类。在我的应用程序中，我用不同的端口实例化了 4 个服务器对象和 4 个客户端对象。

问题是我同时从 4 个客户端向 4 个服务器发送数据，但是每个服务器只有在前一个服务器完成工作时才接收它的数据...

为什么会这样？

这是我的代码：

主要：

std::thread thread;

client cl1(4235),cl2(4245),cl3(4255),cl4(4265);

void handler()
{
    while(1){

        cl1.SendData("HI1",4230);
        cl2.SendData("HI2",4240);
        cl3.SendData("HI3",4250);
        cl4.SendData("HI4",4260);
        std::this_thread::sleep_for(std::chrono::seconds(50));
    }
}

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    server s1(4230);
    server s2(4240);
    server s3(4250);
    server s4(4260);
    thread = std::thread(handler);
    return a.exec();
}

服务器类：

class server : public QObject
{
    Q_OBJECT
public :
    server(int port)
    {
        this->port = port;
        udpSocket = new QUdpSocket();
            udpSocket->bind(QHostAddress::LocalHost, port);

            connect(udpSocket, SIGNAL(readyRead()),
                    this, SLOT(readPendingDatagrams()));
    };
   public  slots:
    void readPendingDatagrams()
    {
        while (udpSocket->hasPendingDatagrams()) {
            QByteArray datagram;
            datagram.resize(udpSocket->pendingDatagramSize());
            QHostAddress sender;
            quint16 senderPort;

            udpSocket->readDatagram(datagram.data(), datagram.size(),
                                    &sender, &senderPort);

            //processTheDatagram(datagram);
            QDateTime dateTime;
            dateTime = dateTime.currentDateTime();
            qDebug() << QString::number(dateTime.time().hour()).rightJustified(2, '0') + ":" +//hour
                        QString::number(dateTime.time().minute()).rightJustified(2, '0') + ":" +//minute
                        QString::number(dateTime.time().second()).rightJustified(2, '0');//seconds
            qDebug() << "\t\tdata received from:" << sender.toString() <<":"<<senderPort << "  data:" << datagram;


            std::this_thread::sleep_for(std::chrono::seconds(5));

            qDebug() << QString::number(dateTime.time().hour()).rightJustified(2, '0') + ":" +//hour
                        QString::number(dateTime.time().minute()).rightJustified(2, '0') + ":" +//minute
                        QString::number(dateTime.time().second()).rightJustified(2, '0');//seconds
            qDebug () << "Sending Response";
            udpSocket->writeDatagram(("HI back from" + QString::number(port)).toUtf8(),sender,senderPort);
        }
    };

private:
    QUdpSocket * udpSocket;
    int port;
};

客户端类：

class client : public QObject
{
    Q_OBJECT
   public:
    client(int port) {
        this->port = port;
        udpSocket = new QUdpSocket();
            udpSocket->bind(QHostAddress::LocalHost, port);

            connect(udpSocket, SIGNAL(readyRead()),
                    this, SLOT(readPendingDatagrams()));
    }
    void SendData(QString Data,int serverport)
    {
        QDateTime dateTime;
        dateTime = dateTime.currentDateTime();


        udpSocket->writeDatagram(Data.toUtf8(),QHostAddress::LocalHost,serverport);
        qDebug() << QString::number(dateTime.time().hour()).rightJustified(2, '0') + ":" +//hour
                    QString::number(dateTime.time().minute()).rightJustified(2, '0') + ":" +//minute
                    QString::number(dateTime.time().second()).rightJustified(2, '0')//sec
                 << "\tclient : " <<port << " sending data to server:" << Data;
    }
   public  slots:
    void readPendingDatagrams()
    {
        while (udpSocket->hasPendingDatagrams()) {
            QByteArray datagram;
            datagram.resize(udpSocket->pendingDatagramSize());
            QHostAddress sender;
            quint16 senderPort;

            udpSocket->readDatagram(datagram.data(), datagram.size(),
                                    &sender, &senderPort);

            //processTheDatagram(datagram);
            QDateTime dateTime;
            dateTime = dateTime.currentDateTime();
            qDebug() << QString::number(dateTime.time().hour()).rightJustified(2, '0') + ":" +//hour
                        QString::number(dateTime.time().minute()).rightJustified(2, '0') + ":" +//minute
                        QString::number(dateTime.time().second()).rightJustified(2, '0');//seconds
            qDebug() << "\t\tclient : " <<port << " data received from:" << sender.toString() <<":"<<senderPort << "  data:" << datagram;
        }
    }

private:
    QUdpSocket * udpSocket;
    int port;
};

这是我的输出数据：

"18:50:07"  client :  4235  sending data to server: "HI1"
"18:50:07"  client :  4245  sending data to server: "HI2"
"18:50:07"  client :  4255  sending data to server: "HI3"
"18:50:07"  client :  4265  sending data to server: "HI4"
"18:50:07"
        data received from: "127.0.0.1" : 4235   data: "HI1"
"18:50:07"
Sending Response
"18:50:12"
        data received from: "127.0.0.1" : 4245   data: "HI2"
"18:50:12"
Sending Response
"18:50:17"
        data received from: "127.0.0.1" : 4255   data: "HI3"
"18:50:17"
Sending Response
"18:50:22"
        data received from: "127.0.0.1" : 4265   data: "HI4"
"18:50:22"
Sending Response

Answer 1

std::this_thread::sleep_for(std::chrono::seconds(5)); 

正在阻塞您当前的线程。看看你的 main()，这也阻塞了主应用程序线程。因此，您的应用程序将不会从操作系统接收有关传入数据包的消息。 如果要并行处理数据，则不应在连接到 readyRead 信号的插槽内使用睡眠函数。