ae6ba06e55
QDoc generates warnings for images that do not have an alternate-text associated with it. Alt-text is required for to increase accessibilty options. This patch adds alt-text to images in the Qt Network Fixes: QTBUG-135122 Pick-to: 6.9 6.8 Change-Id: I690f1d381ef5a9052e189dd1f3906243df557da0 Reviewed-by: Topi Reiniö <topi.reinio@qt.io>
86 lines
3.6 KiB
Plaintext
86 lines
3.6 KiB
Plaintext
// Copyright (C) 2016 The Qt Company Ltd.
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// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GFDL-1.3-no-invariants-only
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/*!
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\example threadedfortuneserver
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\title Threaded Fortune Server
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\examplecategory {Networking}
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\meta tags {tcp,network,threading,server,synchronous-io}
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\ingroup examples-network
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\brief The Threaded Fortune Server example shows how to create a server for a
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simple network service that uses threads to handle requests from different
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clients. It is intended to be run alongside the Fortune Client example.
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\image threadedfortuneserver-example.png {This application creates a server that can a separate thread for each client}
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The implementation of this example is similar to that of the
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\l{fortuneserver}{Fortune Server} example, but here we will
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implement a subclass of QTcpServer that starts each connection in a
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different thread.
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For this we need two classes: FortuneServer, a QTcpServer subclass, and
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FortuneThread, which inherits QThread.
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\snippet threadedfortuneserver/fortuneserver.h 0
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FortuneServer inherits QTcpServer and reimplements
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QTcpServer::incomingConnection(). We also use it for storing the list of
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random fortunes.
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\snippet threadedfortuneserver/fortuneserver.cpp 0
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We use FortuneServer's constructor to simply generate the list of
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fortunes.
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\snippet threadedfortuneserver/fortuneserver.cpp 1
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Our implementation of QTcpServer::incomingConnection() creates a
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FortuneThread object, passing the incoming socket descriptor and a random
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fortune to FortuneThread's constructor. By connecting FortuneThread's
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finished() signal to QObject::deleteLater(), we ensure that the thread
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gets deleted once it has finished. We can then call QThread::start(),
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which starts the thread.
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\snippet threadedfortuneserver/fortunethread.h 0
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Moving on to the FortuneThread class, this is a QThread subclass whose job
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is to write the fortune to the connected socket. The class reimplements
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QThread::run(), and it has a signal for reporting errors.
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\snippet threadedfortuneserver/fortunethread.cpp 0
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FortuneThread's constructor simply stores the socket descriptor and
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fortune text, so that they are available for run() later on.
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\snippet threadedfortuneserver/fortunethread.cpp 1
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The first thing our run() function does is to create a QTcpSocket object
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on the stack. What's worth noticing is that we are creating this object
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inside the thread, which automatically associates the socket to the
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thread's event loop. This ensures that Qt will not try to deliver events
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to our socket from the main thread while we are accessing it from
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FortuneThread::run().
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\snippet threadedfortuneserver/fortunethread.cpp 2
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The socket is initialized by calling QTcpSocket::setSocketDescriptor(),
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passing our socket descriptor as an argument. We expect this to succeed,
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but just to be sure, (although unlikely, the system may run out of
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resources,) we catch the return value and report any error.
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\snippet threadedfortuneserver/fortunethread.cpp 3
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As with the \l{fortuneserver}{Fortune Server} example, we encode
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the fortune into a QByteArray using QDataStream.
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\snippet threadedfortuneserver/fortunethread.cpp 4
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But unlike the previous example, we finish off by calling
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QTcpSocket::waitForDisconnected(), which blocks the calling thread until
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the socket has disconnected. Because we are running in a separate thread,
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the GUI will remain responsive.
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\sa {Fortune Server}, {Fortune Client}, {Blocking Fortune Client}
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*/
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