Qt實(shí)現(xiàn)UDP通信的示例代碼
設(shè)想有如下場景:若干的客戶端與服務(wù)器端建立連接,建立連接后,服務(wù)器端隨機(jī)發(fā)送字符串給客戶端,客戶端打印輸出。該節(jié)案例使用TCP編程。
服務(wù)器端-單線程
頭文件
#pragma once
//
//tcp服務(wù)端-單線程處理客戶端連接
#include <QAbstractSocket>
#include <QObject>
class QTcpServer;
class SimpleTcpSocketServerDemo : public QObject
{
Q_OBJECT
public:
SimpleTcpSocketServerDemo();
private slots:
void sendData();
void displayError(QAbstractSocket::SocketError socketError);
private:
QStringList m_oData;
QTcpServer *m_pTcpServer;
};
void testSimpleTcpSocketServerDemo();源文件
#include "SimpleTcpSocketServerDemo.h"
#include <assert.h>
#include <QTcpServer>
#include <QTcpSocket>
#include <QDebug>
#include <QDataStream>
SimpleTcpSocketServerDemo::SimpleTcpSocketServerDemo()
{
//初始換原始數(shù)據(jù)
m_oData << tr("You've been leading a dog's life. Stay off the furniture.")
<< tr("You've got to think about tomorrow.")
<< tr("You will be surprised by a loud noise.")
<< tr("You will feel hungry again in another hour.")
<< tr("You might have mail.")
<< tr("You cannot kill time without injuring eternity.")
<< tr("Computers are not intelligent. They only think they are.");
//1. 創(chuàng)建TCP對象
m_pTcpServer = new QTcpServer(this);
//2. 新連接、錯(cuò)誤信號
connect(m_pTcpServer, &QTcpServer::newConnection, this, &SimpleTcpSocketServerDemo::sendData);
connect(m_pTcpServer, &QTcpServer::acceptError, this, &SimpleTcpSocketServerDemo::displayError);
//3. 啟動(dòng)服務(wù)端
if (!m_pTcpServer->listen(QHostAddress::Any, 8888))
{
qDebug() << "m_pTcpServer->listen() error";
assert(false);
}
}
void SimpleTcpSocketServerDemo::sendData()
{
//獲取服務(wù)端數(shù)據(jù)
QString sWriteData = m_oData.at(qrand() % m_oData.size());
//獲取與客戶端通信的socket
QTcpSocket* pClientConnection = m_pTcpServer->nextPendingConnection();
//從客戶端讀數(shù)據(jù)
QString sReadData = pClientConnection->readAll();
qDebug() << "SimpleTcpSocketServerDemo::readDataFromClient " << pClientConnection;
//與客戶端寫數(shù)據(jù)
qDebug() << "SimpleTcpSocketServerDemo::writeDataToClient " << sWriteData;
pClientConnection->write(sWriteData.toUtf8());
// //與客戶端斷開連接
// connect(pClientConnection, &QTcpSocket::disconnected, this, &SimpleTcpSocketServerDemo::deleteLater);
// pClientConnection->disconnectFromHost();
}
void SimpleTcpSocketServerDemo::displayError(QAbstractSocket::SocketError socketError)
{
qDebug() << "SimpleTcpSocketServerDemo::displayError " << socketError;
}
void testSimpleTcpSocketServerDemo()
{
//這樣寫會(huì)內(nèi)存泄漏,如此寫方便測試。
SimpleTcpSocketServerDemo* pSimpleTcpSocketServer = new SimpleTcpSocketServerDemo;
}客戶端
頭文件
#pragma once
//
//客戶端
#include <QObject>
#include <QAbstractSocket>
#include <QRunnable>
#include <QThreadPool>
class QTcpSocket;
class SimpleTcpSocketClientDemo : public QObject
{
Q_OBJECT
public:
SimpleTcpSocketClientDemo();
private slots:
void connected();
void readyRead();
void error(QAbstractSocket::SocketError socketError);
private:
QTcpSocket* m_pTcpSocket;
};
class ClientRunnable : public QRunnable
{
public:
void run();
};
void testSimpleTcpSocketClientDemo();源文件
#include "SimpleTcpSocketClientDemo.h"
#include <QTcpSocket>
#include <QDebug>
SimpleTcpSocketClientDemo::SimpleTcpSocketClientDemo()
{
//1. 創(chuàng)建TCP套接字對象
m_pTcpSocket = new QTcpSocket(this);
//2. 已連接、數(shù)據(jù)可讀、失敗信號連接
connect(m_pTcpSocket, &QTcpSocket::connected, this, &SimpleTcpSocketClientDemo::connected);
connect(m_pTcpSocket, &QIODevice::readyRead, this, &SimpleTcpSocketClientDemo::readyRead);
typedef void (QAbstractSocket::*QAbstractSocketErrorSignal)(QAbstractSocket::SocketError);
connect(m_pTcpSocket, static_cast<QAbstractSocketErrorSignal>(&QTcpSocket::error), this, &SimpleTcpSocketClientDemo::error);
//3. 與服務(wù)器端建立連接
m_pTcpSocket->connectToHost("127.0.0.1", 8888);
//4. 同步處理-等待數(shù)據(jù)可讀
m_pTcpSocket->waitForReadyRead();
}
void SimpleTcpSocketClientDemo::readyRead()
{
qDebug() << "SimpleTcpSocketClientDemo::readyRead " << m_pTcpSocket->readAll();
}
void SimpleTcpSocketClientDemo::connected()
{
qDebug() << "SimpleTcpSocketClientDemo::connected successfully";
}
void SimpleTcpSocketClientDemo::error(QAbstractSocket::SocketError socketError)
{
qDebug() << "SimpleTcpSocketClientDemo::error " << socketError;
}
void ClientRunnable::run()
{
//這樣寫會(huì)內(nèi)存泄漏,如此寫方便測試。
SimpleTcpSocketClientDemo* pSimpleTcpSocketClient = new SimpleTcpSocketClientDemo;
}
#define CLINET_COUNT 2000 //客戶端的數(shù)量
void testSimpleTcpSocketClientDemo()
{
QTime oTime;
oTime.start();
//同步線程池的方式模擬多個(gè)客戶端與服務(wù)器端交互
for (int nIndex = 0; nIndex < CLINET_COUNT; ++nIndex)
{
ClientRunnable* pRunnable = new ClientRunnable;
pRunnable->setAutoDelete(false);
QThreadPool::globalInstance()->start(pRunnable);
}
QThreadPool::globalInstance()->waitForDone(30 * 1000);
qDebug() << "connect count: " << CLINET_COUNT << "total time: " << (double)oTime.elapsed() / double(1000) << "s";
}測試結(jié)果-單線程
服務(wù)器端
SimpleTcpSocketServerDemo::readDataFromClient QTcpSocket(0x2f27f308)
SimpleTcpSocketServerDemo::writeDataToClient "You will feel hungry again in another hour."
SimpleTcpSocketServerDemo::readDataFromClient QTcpSocket(0x2eb61cf0)
SimpleTcpSocketServerDemo::writeDataToClient "You might have mail."
.........
客戶端
SimpleTcpSocketClientDemo::connected successfully
SimpleTcpSocketClientDemo::readyRead "You might have mail."
SimpleTcpSocketClientDemo::connected successfully
SimpleTcpSocketClientDemo::readyRead "You will feel hungry again in another hour."
.........
connect count: 2000 total time: 3.926 s
通過測試輸出,可以看到服務(wù)器端與客戶端建立了正確的連接并且數(shù)據(jù)交換。
– 實(shí)際測試數(shù)據(jù):2000個(gè)連接,耗時(shí)4s左右,CPU使用率10%左右。
通過閱讀服務(wù)器端,發(fā)現(xiàn)單線程處理客戶端的連接效率較低。服務(wù)器端可修改為多線程處理客戶端連接,代碼如下:
服務(wù)器端-多線程
頭文件
#pragma once
//
//服務(wù)器端-多線程處理客戶端連接
#include <QTcpServer>
#include <QThread>
class MultiThreadTcpSocketServerDemo : public QTcpServer
{
public:
MultiThreadTcpSocketServerDemo();
//This virtual function is called by QTcpServer when a new connection is available.
//The socketDescriptor argument is the native socket descriptor for the accepted connection.
virtual void incomingConnection(qintptr handle);
private:
QStringList m_oData;
};
//處理線程
class ServerHandleThread : public QThread
{
Q_OBJECT
public:
ServerHandleThread(qintptr handle, const QString& sWriteData);
virtual void run();
private:
qintptr m_nHandle;
QString m_sWriteData;
};
void testMultiThreadTcpSocketServerDemo();//This virtual function is called by QTcpServer when a new connection is available. //The socketDescriptor argument is the native socket descriptor for the accepted connection. virtual void incomingConnection(qintptr handle); //該虛函數(shù)是重點(diǎn)
源文件
#include "MultiThreadTcpSocketServerDemo.h"
#include <QDebug>
#include <QTcpSocket>
MultiThreadTcpSocketServerDemo::MultiThreadTcpSocketServerDemo()
{
//初始換原始數(shù)據(jù)
m_oData << tr("You've been leading a dog's life. Stay off the furniture.")
<< tr("You've got to think about tomorrow.")
<< tr("You will be surprised by a loud noise.")
<< tr("You will feel hungry again in another hour.")
<< tr("You might have mail.")
<< tr("You cannot kill time without injuring eternity.")
<< tr("Computers are not intelligent. They only think they are.");
}
void MultiThreadTcpSocketServerDemo::incomingConnection(qintptr handle)
{
//獲取服務(wù)端數(shù)據(jù)
QString sWriteData = m_oData.at(qrand() % m_oData.size());
qDebug() << "MultiThreadTcpSocketServerDemo::incomingConnection" << handle;
ServerHandleThread* pThread = new ServerHandleThread(handle, sWriteData);
connect(pThread, &ServerHandleThread::finished, pThread, &ServerHandleThread::deleteLater);
pThread->start();
}
ServerHandleThread::ServerHandleThread(qintptr handle, const QString& sWriteData)
:m_sWriteData(sWriteData), m_nHandle(handle)
{
}
void ServerHandleThread::run()
{
//1. 建立與客戶端通信的TCP套接字
QTcpSocket oTcpSocket;
if (!oTcpSocket.setSocketDescriptor(m_nHandle))
{
qDebug() << "oTcpSocket.setSocketDescriptor error";
return;
}
//2. 向客戶端寫數(shù)據(jù)
qDebug() << "MultiThreadTcpSocketServerDemo::readDataFromClient" << &oTcpSocket;
qDebug() << "MultiThreadTcpSocketServerDemo::writeDataToClient" << m_sWriteData;
oTcpSocket.write(m_sWriteData.toUtf8());
oTcpSocket.disconnectFromHost();
oTcpSocket.waitForDisconnected();
}
void testMultiThreadTcpSocketServerDemo()
{
//1. 建立服務(wù)器端套接字
MultiThreadTcpSocketServerDemo* m_pTcpServer = new MultiThreadTcpSocketServerDemo();
//2. 啟動(dòng)服務(wù)端
if (!m_pTcpServer->listen(QHostAddress::Any, 8888))
{
qDebug() << "m_pTcpServer->listen() error";
}
}測試結(jié)果-多線程
客戶端
SimpleTcpSocketClientDemo::connected successfully
SimpleTcpSocketClientDemo::readyRead "You might have mail."
SimpleTcpSocketClientDemo::connected successfully
SimpleTcpSocketClientDemo::readyRead "You will feel hungry again in another hour."
.........
connect count: 2000 total time: 6.403 s
– 實(shí)際測試數(shù)據(jù):2000個(gè)連接,耗時(shí)6.5s左右,CPU使用率20%左右。
可見服務(wù)器端采用多線程可充分利用CPU,但是頻繁的切換線程也會(huì)性能下降(耗時(shí))。
通過本案例的代碼實(shí)現(xiàn)可以了解TCP服務(wù)器端/客戶端編程的基本思路。并且驗(yàn)證了服務(wù)器端單線程和多線程的效率對比。 在windows中,可通過IOCP提高服務(wù)期端的效率,后面會(huì)詳細(xì)講解。
到此這篇關(guān)于Qt實(shí)現(xiàn)UDP通信的示例代碼的文章就介紹到這了,更多相關(guān)Qt UDP通信內(nèi)容請搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關(guān)文章希望大家以后多多支持腳本之家!
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