| 1 | /****************************************************************************
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| 2 | **
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| 3 | ** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
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| 4 | ** All rights reserved.
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| 5 | ** Contact: Nokia Corporation ([email protected])
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| 6 | **
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| 7 | ** This file is part of the documentation of the Qt Toolkit.
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| 8 | **
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| 9 | ** $QT_BEGIN_LICENSE:FDL$
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| 10 | ** Commercial Usage
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| 11 | ** Licensees holding valid Qt Commercial licenses may use this file in
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| 12 | ** accordance with the Qt Commercial License Agreement provided with the
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| 13 | ** Software or, alternatively, in accordance with the terms contained in a
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| 14 | ** written agreement between you and Nokia.
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| 15 | **
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| 16 | ** GNU Free Documentation License
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| 17 | ** Alternatively, this file may be used under the terms of the GNU Free
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| 18 | ** Documentation License version 1.3 as published by the Free Software
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| 19 | ** Foundation and appearing in the file included in the packaging of this
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| 20 | ** file.
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| 21 | **
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| 22 | ** If you have questions regarding the use of this file, please contact
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| 23 | ** Nokia at [email protected].
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| 24 | ** $QT_END_LICENSE$
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| 25 | **
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| 26 | ****************************************************************************/
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| 27 |
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| 28 | /*!
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| 29 | \page ipc.html
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| 30 | \title Inter-Process Communication in Qt
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| 31 | \brief Inter-Process communication in Qt applications.
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| 32 |
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| 33 | \ingroup technology-apis
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| 34 | \ingroup qt-basic-concepts
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| 35 | \ingroup qt-network
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| 36 |
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| 37 | Qt provides several ways to implement Inter-Process Communication
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| 38 | (IPC) in Qt applications.
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| 39 |
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| 40 | \section1 TCP/IP
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| 41 |
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| 42 | The cross-platform \l{QtNetwork} module provides classes that make
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| 43 | network programming portable and easy. It offers high-level
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| 44 | classes (e.g., QNetworkAccessManager, QFtp) that communicate using
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| 45 | specific application-level protocols, and lower-level classes
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| 46 | (e.g., QTcpSocket, QTcpServer, QSslSocket) for implementing
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| 47 | protocols.
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| 48 |
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| 49 | \section1 Shared Memory
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| 50 |
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| 51 | The cross-platform shared memory class, QSharedMemory, provides
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| 52 | access to the operating system's shared memory implementation.
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| 53 | It allows safe access to shared memory segments by multiple threads
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| 54 | and processes. Additionally, QSystemSemaphore can be used to control
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| 55 | access to resources shared by the system, as well as to communicate
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| 56 | between processes.
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| 57 |
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| 58 | \section1 D-Bus
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| 59 |
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| 60 | The \l{QtDBus} module is a Unix-only library you can use to
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| 61 | implement IPC using the D-Bus protocol. It extends Qt's
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| 62 | \l{signalsandslots.html} {Signals and Slots} mechanism to the IPC
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| 63 | level, allowing a signal emitted by one process to be connected to
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| 64 | a slot in another process. This \l {D-Bus} page has detailed
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| 65 | information on how to use the \l{QtDBus} module.
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| 66 |
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| 67 | \section1 Qt COmmunications Protocol (QCOP)
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| 68 |
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| 69 | The QCopChannel class implements a protocol for transferring messages
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| 70 | between client processes across named channels. QCopChannel is
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| 71 | only available in \l{Qt for Embedded Linux}. Like the \l{QtDBus}
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| 72 | module, QCOP extends Qt's \l{Signals and Slots} mechanism to the
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| 73 | IPC level, allowing a signal emitted by one process to be
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| 74 | connected to a slot in another process, but unlike QtDBus, QCOP
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| 75 | does not depend on a third party library.
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| 76 | */
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