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diff --git a/examples/network/doc/src/threadedfortuneserver.qdoc b/examples/network/doc/src/threadedfortuneserver.qdoc new file mode 100644 index 0000000000..33b6892363 --- /dev/null +++ b/examples/network/doc/src/threadedfortuneserver.qdoc @@ -0,0 +1,107 @@ +/**************************************************************************** +** +** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies). +** Contact: http://www.qt-project.org/ +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:FDL$ +** GNU Free Documentation License +** Alternatively, this file may be used under the terms of the GNU Free +** Documentation License version 1.3 as published by the Free Software +** Foundation and appearing in the file included in the packaging of +** this file. +** +** Other Usage +** Alternatively, this file may be used in accordance with the terms +** and conditions contained in a signed written agreement between you +** and Nokia. +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! + \example threadedfortuneserver + \title Threaded Fortune Server Example + + The Threaded Fortune Server example shows how to create a server for a + simple network service that uses threads to handle requests from different + clients. It is intended to be run alongside the Fortune Client example. + + \image threadedfortuneserver-example.png + + The implementation of this example is similar to that of the + \l{fortuneserver}{Fortune Server} example, but here we will + implement a subclass of QTcpServer that starts each connection in a + different thread. + + For this we need two classes: FortuneServer, a QTcpServer subclass, and + FortuneThread, which inherits QThread. + + \snippet threadedfortuneserver/fortuneserver.h 0 + + FortuneServer inherits QTcpServer and reimplements + QTcpServer::incomingConnection(). We also use it for storing the list of + random fortunes. + + \snippet threadedfortuneserver/fortuneserver.cpp 0 + + We use FortuneServer's constructor to simply generate the list of + fortunes. + + \snippet threadedfortuneserver/fortuneserver.cpp 1 + + Our implementation of QTcpServer::incomingConnection() creates a + FortuneThread object, passing the incoming socket descriptor and a random + fortune to FortuneThread's constructor. By connecting FortuneThread's + finished() signal to QObject::deleteLater(), we ensure that the thread + gets deleted once it has finished. We can then call QThread::start(), + which starts the thread. + + \snippet threadedfortuneserver/fortunethread.h 0 + + Moving on to the FortuneThread class, this is a QThread subclass whose job + is to write the fortune to the connected socket. The class reimplements + QThread::run(), and it has a signal for reporting errors. + + \snippet threadedfortuneserver/fortunethread.cpp 0 + + FortuneThread's constructor simply stores the socket descriptor and + fortune text, so that they are available for run() later on. + + \snippet threadedfortuneserver/fortunethread.cpp 1 + + The first thing our run() function does is to create a QTcpSocket object + on the stack. What's worth noticing is that we are creating this object + inside the thread, which automatically associates the socket to the + thread's event loop. This ensures that Qt will not try to deliver events + to our socket from the main thread while we are accessing it from + FortuneThread::run(). + + \snippet threadedfortuneserver/fortunethread.cpp 2 + + The socket is initialized by calling QTcpSocket::setSocketDescriptor(), + passing our socket descriptor as an argument. We expect this to succeed, + but just to be sure, (although unlikely, the system may run out of + resources,) we catch the return value and report any error. + + \snippet threadedfortuneserver/fortunethread.cpp 3 + + As with the \l{fortuneserver}{Fortune Server} example, we encode + the fortune into a QByteArray using QDataStream. + + \snippet threadedfortuneserver/fortunethread.cpp 4 + + But unlike the previous example, we finish off by calling + QTcpSocket::waitForDisconnected(), which blocks the calling thread until + the socket has disconnected. Because we are running in a separate thread, + the GUI will remain responsive. + + \sa {Fortune Server Example}, {Fortune Client Example}, {Blocking Fortune + Client Example} +*/ |