qt tcp server 的正确姿势

63 阅读 0 评论 42 点赞

我是靠谱客的博主慈祥皮卡丘，最近开发中收集的这篇文章主要介绍qt tcp server 的正确姿势，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

qt 作为桌面应用本来不应该用来做 tcp server的，但是架不住甲方的需求太奇葩，只能忍了。

第一版：

// 初始化
{
...
m_pTcpServer = new QTcpServer(this);
connect(m_pTcpServer, &QTcpServer::newConnection, this, &tcpSer::ConnCli);
connect(m_pTcpServer, &QTcpServer::acceptError, this, &tcpSer::displayError);
...
}
// 客户端连接后起线程读写数据
void tcpSer::ConnCli()
{
//获取与客户端通信的socket
QTcpSocket* pClientConnection = m_pTcpServer->nextPendingConnection();
//从客户端读数据
//
QString key = pClientConnection->peerAddress().toString() + pClientConnection->peerPort();
m_pCliVec.append(pClientConnection);
std::thread cliThread = std::thread(&tcpSer::cliThread, this, pClientConnection);
cliThread.detach();
}
// 读写连接的客户端数据
void tcpSer::cliThread(QTcpSocket*
cli)
{
QString key = cli->peerAddress().toString() + cli->peerPort();
qDebug() << "tcpSer::client conn " << key;
bool loop = true;
connect(cli, &QTcpSocket::disconnected, this, [&]{
loop = false;
});
connect(cli, &QIODevice::readyRead, this, [&](){
QByteArray recvMsg = cli->readAll();
if(recvMsg.size() == 0){
return;
}
commHandle(recvMsg.toStdString());
});
while(loop){
QThread::sleep(5);
}
qDebug() << "tcpSer::client disconn " << key;
pthread_detach(pthread_self());
}

存在的问题：

readyRead 当有连续数据的时候，只触发一次，导致接收多个数据单只读了一包，后面再来数据之后，又形成了粘包。

第二版：

void tcpSer::cliThread(QTcpSocket*
cli)
{
QString key = cli->peerAddress().toString() + cli->peerPort();
qDebug() << "tcpSer::client conn " << key;
bool loop = true;
connect(cli, &QTcpSocket::disconnected, this, [&]{
loop = false;
});
while(loop){
if(!iotConn->waitForConnected(1000)){
std::cout<< "reconnect iotHub" << std::endl;
}
if(iotConn->waitForReadyRead(1000) == false){
continue;
}
QByteArray recvMsg = iotConn->readAll();
commHandle(recvMsg.toStdString());
}
qDebug() << "tcpSer::client disconn " << key;
pthread_detach(pthread_self());
}

问题更可怕，当客户端连上发了一包数据马上断开后，直接程序段错误挂了。

最终版：

void tcpSer::cliThread(QTcpSocket*
cli)
{
QString key = cli->peerAddress().toString() + cli->peerPort();
qDebug() << "tcpSer::client conn " << key;
bool loop = true;
connect(cli, &QTcpSocket::disconnected, this, [&]{
loop = false;
});
while(loop){
QByteArray recvInfo = cli->read(BUFF_SIZE);
if(recvInfo.size() == 0){
QThread::msleep(100);
continue;
}
m_DataRecv.append(recvInfo);
commHandle(recvMsg.toStdString());
}
qDebug() << "tcpSer::client disconn " << key;
pthread_detach(pthread_self());
}

最终版暴力断开连接多次，都抗住了，没有发生异常。