我需要处理各个QThread
上的传入TCP连接。
成功的客户端身份验证后,相应的套接字应存储在QList
对象中。
[简化的主/服务器端应用程序]
class Server : public QObject
{
Q_OBJECT
public:
Server();
private:
QList<QTcpSocket*> m_connections;
QTcpServer m_server;
void handleIncomingConnection();
void handleWaiterThread();
private slots:
void treatFinishedWaiterThread();
}
[根据功能定义]
handleIncomingConnection()
插槽与服务器对象的(m_server)newConnection()
信号连接。void Server::handleIncomingConnection()
{
QThread *waiter = new QThread();
connect(waiter, SIGNAL(started()), this, SLOT(handleWaiterThread()));
connect(waiter, SIGNAL(finished()), this, SLOT(treatFinishedWaiterThread()));
moveToThread(waiter);
waiter->start();
}
void Server::handleWaiterThread()
{
// fetch requesting socket
QTcpSocket *socket = m_server->nextPendingConnection();
// HANDLE PASSWORD AUTHENTICATION HERE ...
// IF SUCCESSFUL, CONTINUE
connect(socket, SIGNAL(disconnected()), this, SLOT(clientDisconnected()));
// add to list
m_connections.append(socket);
}
void Server::treatFinishedWaiterThread()
{
QThread *caller = qobject_cast<QThread*>(sender());
caller->deleteLater();
}
如果我尝试运行此线程,则会创建线程,但完成后不会发出任何SIGNAL信号,因此以后无法删除线程。另外,我收到此消息:
QObject :: moveToThread:不能将小部件移动到新线程
如何解决这个问题?
[01.06.2016]
根据QTcpServer::nextPendingConnection()它说:
返回的QTcpSocket对象不能从另一个线程使用。如果要使用来自另一个线程的传入连接,则需要重写传入连接()。
因此,最后我必须创建另一个从
QTcpServer
继承的类。[01.07.2016#1]
我修改了代码,并添加了自定义服务器和服务程序线程类。
[自定义服务器类]
class CustomServer : public QTcpServer
{
Q_OBJECT
public:
WServer(QObject* = nullptr) : QTcpServer(parent) {}
signals:
void connectionRequest(qintptr);
protected:
void incomingConnection(qintptr socketDescriptor)
{
emit connectionRequest(socketDescriptor);
}
};
[自定义线程类]
class Waiter : public QThread
{
Q_OBJECT
public:
Waiter(qintptr socketDescriptor, QObject *parent = nullptr)
: QThread(parent)
{
// Create socket
m_socket = new QTcpSocket(this);
m_socket->setSocketDescriptor(socketDescriptor);
}
signals:
void newSocket(QTcpSocket*);
protected:
void run()
{
// DO STUFF HERE
msleep(2500);
emit newSocket(m_socket);
}
private:
QTcpSocket *m_socket;
};
[新主班]
class ServerGUI : public QWidget
{
Q_OBJECT
public:
Server(QObject*);
private:
QList<QTcpSocket*> m_connections;
CustomServer m_server;
private slots:
void handleConnectionRequest(qintptr);
void handleNewSocket(QTcpSocket*);
}
void CustomServer::handleConnectionRequest(qintptr socketDescriptor)
{
Waiter *nextWaiter = new Waiter(socketDescriptor, this);
connect(nextWaiter, SIGNAL(newSocket(QTcpSocket*)), this, SLOT(handleNewSocket(QTcpSocket*)));
connect(nextWaiter, SIGNAL(finished()), this, SLOT(deleteLater()));
nextWaiter->start();
}
void CustomServer::handleNewSocket(QTcpSocket *socket)
{
// DO STUFF HERE ...
connect(socket, SIGNAL(disconnected()), this, SLOT(clientDisconnected()));
// FINALLY ADD TO ACTIVE-CLIENT LIST ...
}
信号和插槽特定设置:
由于
CustomServer
被定义为我的主窗口小部件类(处理GUI;称为ServerGUI
)中的类成员(m_server),m_server的
connectionRequest(qintptr)
信号与handleConnectionRequest(qintptr)
实例的ServerGUI
插槽连接。但是现在我的应用程序启动后立即崩溃,在调试窗口中显示以下消息:
HEAP [qtapp.exe]:指定给RtlValidateHeap(000002204F430000,0000006E0090F4C0)的无效地址
这可能是什么原因?
[01.10.2016#2]
我根据user2014561的答案修改了我的代码。
对于
CustomServer
类class CustomServer : public QTcpServer
{
Q_OBJECT
public:
WServer(QHostAddress, quint16, quint16, QObject* = nullptr);
~WServer();
void kickAll();
void kickClient(qintptr);
QHostAddress localAddress() const;
quint16 serverPort() const;
bool isReady() const;
bool alreadyConnected(qintptr) const;
bool clientLimitExhausted() const;
signals:
void clientConnected(qintptr);
void clientDisconnected(qintptr);
private slots:
void destroyedfunc(QObject*);
// JUST FOR TESTING PURPOSES
void waiterFinished();
private:
QList<ServerPeer*> m_connections;
quint16 m_maxAllowedClients;
bool m_readyState;
void incomingConnection(qintptr);
};
对于
kickAll()
:void WServer::kickAll()
{
while (!m_connections.isEmpty())
{
ServerPeer *peer = m_connections.first();
QEventLoop loop;
connect(peer->thread(), SIGNAL(destroyed()), &loop, SLOT(quit())); // ### PROBLEM ENCOUNTERED HERE
QMetaObject::invokeMethod(peer, "deleteLater", Qt::QueuedConnection);
loop.exec();
}
}
对于
kickClient(qintptr)
:void WServer::kickClient(qintptr client_id)
{
foreach (ServerPeer *peer, m_connections)
{
bool peerState;
QMetaObject::invokeMethod(peer, "hasSocket", Qt::BlockingQueuedConnection,
Q_RETURN_ARG(bool, peerState), Q_ARG(qintptr, client_id));
if (peerState)
{
QEventLoop loop;
connect(peer->thread(), SIGNAL(destroyed()), &loop, SLOT(quit()));
QMetaObject::invokeMethod(peer, "deleteLater", Qt::QueuedConnection);
loop.exec();
break;
}
}
}
对于
destroyedfunc(QObject*)
:void CustomServer::destroyedfunc(QObject *obj)
{
ServerPeer *peer = static_cast<ServerPeer*>(obj);
m_connections.removeAll(peer);
}
对于
incomingConnection(qintptr)
:void WServer::incomingConnection(qintptr handle)
{
ServerPeer *peer = new ServerPeer();
QThread *waiter = new QThread();
m_connections.append(peer); // add to list
peer->moveToThread(waiter);
// notify about client connect
connect(peer, SIGNAL(connected(qintptr)), this, SIGNAL(clientConnected(qintptr)));
// stop waiter thread by indirectly raising finished() signal
connect(peer, SIGNAL(finished()), waiter, SLOT(quit()));
// notify about client disconnect
connect(peer, SIGNAL(disconnected(qintptr)), this, SIGNAL(clientDisconnected(qintptr)));
// remove client from list
connect(peer, SIGNAL(destroyed(QObject*)), this, SLOT(destroyedfunc(QObject*)));
// notify about finished waiter thread; only for debug purposes
connect(waiter, SIGNAL(finished()), this, SLOT(waiterFinished()));
// remove waiter thread when finished
connect(waiter, SIGNAL(finished()), waiter, SLOT(deleteLater()));
QMetaObject::invokeMethod(peer, "start", Qt::QueuedConnection,
Q_ARG(qintptr, handle));
waiter->start();
}
对于
ServerPeer
类class ServerPeer : public QObject
{
Q_OBJECT
public:
ServerPeer(QObject* = nullptr);
~ServerPeer();
bool hasSocket(qintptr) const;
signals:
void connected(qintptr);
void disconnected(qintptr);
void finished();
public slots:
void start(qintptr);
void disconnect();
private slots :
void notifyConnect();
void notifyDisconnect();
private:
QTcpSocket *m_peer;
qintptr m_id;
};
对于
ServerPeer(QObject*)
:ServerPeer::ServerPeer(QObject *parent) : QObject(parent), m_peer(nullptr)
{
}
对于
~ServerPeer()
:ServerPeer::~ServerPeer()
{
disconnect();
}
对于
start(qintptr)
:void ServerPeer::start(qintptr handle)
{
qDebug() << "New waiter thread has been started.";
m_peer = new QTcpSocket(this);
if (!m_peer->setSocketDescriptor(handle))
{
this->deleteLater();
return;
}
if (true /*verification here*/)
{
connect(m_peer, SIGNAL(disconnected()), this, SLOT(notifyDisconnect()));
connect(m_peer, SIGNAL(disconnected()), this, SLOT(deleteLater()));
// manually do connected notification
QTimer::singleShot(0, this, SLOT(notifyConnect()));
}
else
{
this->deleteLater();
}
emit finished();
}
对于
disconnect()
:void ServerPeer::disconnect()
{
if (m_peer != nullptr)
{
if (m_peer->state() != QAbstractSocket::SocketState::ClosingState
&& m_peer->state() != QAbstractSocket::SocketState::UnconnectedState)
m_peer->abort();
delete m_peer;
m_peer = nullptr;
}
}
对于
notifyConnect()
:void ServerPeer::notifyConnect()
{
emit connected(m_peer);
}
对于
notifyDisconnect()
:void ServerPeer::notifyDisconnect()
{
emit disconnected(m_peer);
}
对于
ServerGUI
类class ServerGUI : public QWidget
{
Q_OBJECT
public:
ServerGUI(QWidget* = nullptr);
private:
Ui::ServerWindow ui;
CustomServer *m_server;
private slots:
// For further handling, e.g. updating client view
void handleNewClient(qintptr);
void handleRemovedClient(qintptr);
}
对于
ServerGUI(QWidget*)
:ServerGUI::ServerGUI(QWidget *parent) : QWidget(parent)
{
// initialize gui elements;
// GENERATED WITH ACCORDING *.ui FILE
ui.setupUi(this);
m_server = new WServer(QHostAddress::LocalHost, 1234, 2, this);
if (!m_server->isReady())
{
qDebug() << "Server could not start!";
delete m_server;
m_server = nullptr;
return;
}
connect(m_server, SIGNAL(clientConnected(qintptr)), this, SLOT(handleNewClient(qintptr)));
connect(m_server, SIGNAL(clientDisconnected(qintptr)), this, SLOT(handleRemovedClient(qintptr)));
}
这是我的主要功能:
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
ServerGUI w;
w.show();
return a.exec();
}
使用给定的代码,如果我尝试踢一个(选定的)客户端,则会弹出以下消息:
QMetaObject :: invokeMethod:没有这样的方法ServerPeer :: hasSocket(qintptr)
QObject :: connect:无法将(null):: destroyed()连接到QEventLoop :: quit()
如何解决这个问题?
最佳答案
如果我理解正确,那么您希望在单独的线程上运行服务器的每个对等方,如果可以,那么以下内容可能会对您有所帮助:
创建QTcpServer
的子类
重新实现incomingConnection()
方法
创建QThread
和ServerPeer
的实例(无父级)并启动线程
进行SIGNAL
-SLOT
连接以从列表中删除对等方,并删除线程和对等方实例
将ServerPeer
添加到您的QList
一旦开始,请进行凭据验证;如果拒绝它们,则中止连接
编辑,注意事项:
您没有connected
SIGNAL
,因为当您将socketDescriptor设置为已连接套接字时,您可以简单地假定setSocketDescriptor
之后已连接套接字并执行您想要的操作。
关于关闭时的错误,是由于您没有正确释放线程而发生的,请参见我的编辑该如何解决。
最后,QTcpSocket
绝对不能被不同的线程访问,如果您需要从另一个线程调用ServerPeer
,请使用QMetaObject::invokeMethod
和QueuedConnection
或BlockingQueuedConnection
和SIGNAL
SLOT
机制。
编辑2:
现在,服务器及其对等节点将在MainWindow::closeEvent
上删除,这样您就可以看到被断开的函数。我猜问题是根据删除类的顺序而发生的。
您可以与套接字进行交互,包括通过套接字发送数据,但是我相信将Qt方法用于已经提到的跨线程调用将很轻松。在我的示例中,您可以轻松地写入特定对等方或所有对等方。
customserver.h:
//Step 1
#include <QtCore>
#include <QtNetwork>
#include "serverpeer.h"
class CustomServer : public QTcpServer
{
Q_OBJECT
public:
explicit CustomServer(const QHostAddress &host, quint16 port, quint16 maxconnections, QObject *parent = nullptr);
~CustomServer();
void kickAll();
void kickClient(qintptr id);
void writeData(const QByteArray &data, qintptr id);
void writeData(const QByteArray &data);
QHostAddress localAddress();
quint16 serverPort();
bool isReady();
signals:
void clientConnected(qintptr);
void clientDisconnected(qintptr);
private slots:
void destroyedfunc(QObject *obj);
private:
void incomingConnection(qintptr handle);
QList<ServerPeer*> m_connections;
int m_maxAllowedClients;
};
customserver.cpp:
#include "customserver.h"
CustomServer::CustomServer(const QHostAddress &host, quint16 port, quint16 maxconnections, QObject *parent) :
m_maxAllowedClients(maxconnections), QTcpServer(parent)
{
listen(host, port);
}
CustomServer::~CustomServer()
{
kickAll();
}
//Step 2
void CustomServer::incomingConnection(qintptr handle)
{
// handle client limit
if (m_connections.size() >= m_maxAllowedClients)
{
qDebug() << "Can't allow new connection: client limit reached!";
QTcpSocket *socket = new QTcpSocket();
socket->setSocketDescriptor(handle);
socket->abort();
delete socket;
return;
}
//Step 3
ServerPeer *peer = new ServerPeer();
QThread *waiter = new QThread();
peer->moveToThread(waiter);
//Step 4
connect(peer, SIGNAL(connected(qintptr)), this, SIGNAL(clientConnected(qintptr)));
connect(peer, SIGNAL(disconnected(qintptr)), this, SIGNAL(clientDisconnected(qintptr)));
connect(peer, SIGNAL(destroyed()), waiter, SLOT(quit()));
connect(peer, SIGNAL(destroyed(QObject*)), this, SLOT(destroyedfunc(QObject*)));
connect(waiter, SIGNAL(finished()), waiter, SLOT(deleteLater()));
QMetaObject::invokeMethod(peer, "start", Qt::QueuedConnection, Q_ARG(qintptr, handle));
waiter->start();
//Step 5
m_connections.append(peer);
}
void CustomServer::kickAll()
{
while (!m_connections.isEmpty())
{
ServerPeer *peer = m_connections.first();
QEventLoop loop;
connect(peer->thread(), SIGNAL(destroyed()), &loop, SLOT(quit()));
QMetaObject::invokeMethod(peer, "deleteLater", Qt::QueuedConnection);
loop.exec();
}
}
void CustomServer::kickClient(qintptr id)
{
foreach (ServerPeer *peer, m_connections)
{
ServerPeer::State hassocket;
QMetaObject::invokeMethod(peer, "hasSocket", Qt::BlockingQueuedConnection, Q_RETURN_ARG(ServerPeer::State, hassocket), Q_ARG(qintptr, id));
if (hassocket == ServerPeer::MyTRUE)
{
QEventLoop loop;
connect(peer->thread(), SIGNAL(destroyed()), &loop, SLOT(quit()));
QMetaObject::invokeMethod(peer, "deleteLater", Qt::QueuedConnection);
loop.exec();
break;
}
}
}
void CustomServer::writeData(const QByteArray &data)
{
foreach (ServerPeer *peer, m_connections)
QMetaObject::invokeMethod(peer, "writeData", Qt::QueuedConnection, Q_ARG(QByteArray, data));
}
void CustomServer::writeData(const QByteArray &data, qintptr id)
{
foreach (ServerPeer *peer, m_connections)
{
ServerPeer::State hassocket;
QMetaObject::invokeMethod(peer, "hasSocket", Qt::BlockingQueuedConnection, Q_RETURN_ARG(ServerPeer::State, hassocket), Q_ARG(qintptr, id));
if (hassocket == ServerPeer::MyTRUE)
{
QMetaObject::invokeMethod(peer, "writeData", Qt::QueuedConnection, Q_ARG(QByteArray, data));
break;
}
}
}
QHostAddress CustomServer::localAddress()
{
return QTcpServer::serverAddress();
}
quint16 CustomServer::serverPort()
{
return QTcpServer::serverPort();
}
bool CustomServer::isReady()
{
return QTcpServer::isListening();
}
void CustomServer::destroyedfunc(QObject *obj)
{
ServerPeer *peer = static_cast<ServerPeer*>(obj);
m_connections.removeAll(peer);
}
serverpeer.h:
#include <QtCore>
#include <QtNetwork>
class ServerPeer : public QObject
{
Q_OBJECT
public:
explicit ServerPeer(QObject *parent = nullptr);
~ServerPeer();
enum State
{
MyTRUE,
MyFALSE
};
signals:
void connected(qintptr id);
void disconnected(qintptr id);
public slots:
ServerPeer::State hasSocket(qintptr id);
void start(qintptr handle);
void writeData(const QByteArray &data);
private slots:
void readyRead();
void notifyConnect();
void notifyDisconnect();
private:
QTcpSocket *m_peer;
qintptr m_id;
};
serverpeer.cpp:
#include "serverpeer.h"
ServerPeer::ServerPeer(QObject *parent) : QObject(parent), m_peer(nullptr)
{
}
ServerPeer::~ServerPeer()
{
if (m_peer)
m_peer->abort();
}
ServerPeer::State ServerPeer::hasSocket(qintptr id)
{
if (m_id == id)
return MyTRUE;
else
return MyFALSE;
}
void ServerPeer::start(qintptr handle)
{
m_peer = new QTcpSocket(this);
m_peer->setSocketDescriptor(handle);
//Step 6
if (true /*verification here*/)
{
m_id = handle;
QTimer::singleShot(0, this, SLOT(notifyConnect()));
connect(m_peer, SIGNAL(readyRead()), this, SLOT(readyRead()));
connect(m_peer, SIGNAL(disconnected()), this, SLOT(notifyDisconnect()));
connect(m_peer, SIGNAL(disconnected()), this, SLOT(deleteLater()));
}
else
{
m_peer->abort();
this->deleteLater();
}
}
void ServerPeer::readyRead()
{
qDebug() << m_peer->readAll() << QThread::currentThread();
}
void ServerPeer::writeData(const QByteArray &data)
{
m_peer->write(data);
m_peer->flush();
}
void ServerPeer::notifyConnect()
{
emit connected(m_id);
}
void ServerPeer::notifyDisconnect()
{
emit disconnected(m_id);
}
mainwindow.cpp:
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
qRegisterMetaType<qintptr>("qintptr");
m_server = new CustomServer(QHostAddress::LocalHost, 1024, 2, this);
if (!m_server->isReady())
{
qDebug() << "Server could not start!";
delete m_server;
m_server = nullptr;
return;
}
connect(m_server, SIGNAL(clientConnected(qintptr)), this, SLOT(handleNewClient(qintptr)));
connect(m_server, SIGNAL(clientDisconnected(qintptr)), this, SLOT(handleRemovedClient(qintptr)));
}
MainWindow::~MainWindow()
{
delete ui;
}
void MainWindow::closeEvent(QCloseEvent *)
{
if (m_server)
{
delete m_server;
m_server = nullptr;
}
}
void MainWindow::handleNewClient(qintptr id)
{
qDebug() << __FUNCTION__ << id;
m_server->writeData(QString("Hello client id: %0\r\n").arg(id).toLatin1(), id);
m_server->writeData(QString("New client id: %0\r\n").arg(id).toLatin1());
}
void MainWindow::handleRemovedClient(qintptr id)
{
qDebug() << __FUNCTION__ << id;
}
关于qt - 在另一个QThread中处理QTcpSocket,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/34641732/