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Branched from the monolithic repo, Qt master branch, at commit
896db169ea224deb96c59ce8af800d019de63f12

1 files changed, 323 insertions, 0 deletions

diff --git a/src/corelib/kernel/qsocketnotifier.cpp b/src/corelib/kernel/qsocketnotifier.cpp
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+/****************************************************************************
+**
+** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qsocketnotifier.h"
+
+#include "qplatformdefs.h"
+
+#include "qabstracteventdispatcher.h"
+#include "qcoreapplication.h"
+
+#include "qobject_p.h"
+#include <private/qthread_p.h>
+
+QT_BEGIN_NAMESPACE
+
+/*!
+    \class QSocketNotifier
+    \brief The QSocketNotifier class provides support for monitoring
+    activity on a file descriptor.
+
+    \ingroup network
+    \ingroup io
+
+    The QSocketNotifier makes it possible to integrate Qt's event
+    loop with other event loops based on file descriptors. For
+    example, the \l{CORBA Framework} uses it to process CORBA
+    events.  File descriptor action is detected in Qt's main event
+    loop (QCoreApplication::exec()).
+
+    \target write notifiers
+
+    Once you have opened a device using a low-level (usually
+    platform-specific) API, you can create a socket notifier to
+    monitor the file descriptor. The socket notifier is enabled by
+    default, i.e. it emits the activated() signal whenever a socket
+    event corresponding to its type occurs. Connect the activated()
+    signal to the slot you want to be called when an event
+    corresponding to your socket notifier's type occurs.
+
+    There are three types of socket notifiers: read, write, and
+    exception. The type is described by the \l Type enum, and must be
+    specified when constructing the socket notifier. After
+    construction it can be determined using the type() function. Note
+    that if you need to monitor both reads and writes for the same
+    file descriptor, you must create two socket notifiers. Note also
+    that it is not possible to install two socket notifiers of the
+    same type (\l Read, \l Write, \l Exception) on the same socket.
+
+    The setEnabled() function allows you to disable as well as enable
+    the socket notifier. It is generally advisable to explicitly
+    enable or disable the socket notifier, especially for write
+    notifiers. A disabled notifier ignores socket events (the same
+    effect as not creating the socket notifier). Use the isEnabled()
+    function to determine the notifier's current status.
+
+    Finally, you can use the socket() function to retrieve the
+    socket identifier.  Although the class is called QSocketNotifier,
+    it is normally used for other types of devices than sockets.
+    QTcpSocket and QUdpSocket provide notification through signals, so
+    there is normally no need to use a QSocketNotifier on them.
+
+    \section1 Notes for Windows Users
+
+    The socket passed to QSocketNotifier will become non-blocking, even if
+    it was created as a blocking socket.
+    The activated() signal is sometimes triggered by high general activity
+    on the host, even if there is nothing to read. A subsequent read from
+    the socket can then fail, the error indicating that there is no data
+    available (e.g., \c{WSAEWOULDBLOCK}). This is an operating system
+    limitation, and not a bug in QSocketNotifier.
+
+    To ensure that the socket notifier handles read notifications correctly,
+    follow these steps when you receive a notification:
+
+    \list 1
+    \o Disable the notifier.
+    \o Read data from the socket.
+    \o Re-enable the notifier if you are interested in more data (such as after
+       having written a new command to a remote server).
+    \endlist
+
+    To ensure that the socket notifier handles write notifications correctly,
+    follow these steps when you receive a notification:
+
+    \list 1
+    \o Disable the notifier.
+    \o Write as much data as you can (before \c EWOULDBLOCK is returned).
+    \o Re-enable notifier if you have more data to write.
+    \endlist
+
+    \bold{Further information:}
+    On Windows, Qt always disables the notifier after getting a notification,
+    and only re-enables it if more data is expected. For example, if data is
+    read from the socket and it can be used to read more, or if reading or
+    writing is not possible because the socket would block, in which case
+    it is necessary to wait before attempting to read or write again.
+
+    \sa QFile, QProcess, QTcpSocket, QUdpSocket
+*/
+
+/*!
+    \enum QSocketNotifier::Type
+
+    This enum describes the various types of events that a socket
+    notifier can recognize. The type must be specified when
+    constructing the socket notifier.
+
+    Note that if you need to monitor both reads and writes for the
+    same file descriptor, you must create two socket notifiers. Note
+    also that it is not possible to install two socket notifiers of
+    the same type (Read, Write, Exception) on the same socket.
+
+    \value Read      There is data to be read.
+    \value Write      Data can be written.
+    \value Exception  An exception has occurred. We recommend against using this.
+
+    \sa QSocketNotifier(), type()
+*/
+
+/*!
+    Constructs a socket notifier with the given \a parent. It enables
+    the \a socket, and watches for events of the given \a type.
+
+    It is generally advisable to explicitly enable or disable the
+    socket notifier, especially for write notifiers.
+
+    \bold{Note for Windows users:} The socket passed to QSocketNotifier
+    will become non-blocking, even if it was created as a blocking socket.
+
+    \sa setEnabled(), isEnabled()
+*/
+
+QSocketNotifier::QSocketNotifier(int socket, Type type, QObject *parent)
+    : QObject(parent)
+{
+    if (socket < 0)
+        qWarning("QSocketNotifier: Invalid socket specified");
+    sockfd = socket;
+    sntype = type;
+    snenabled = true;
+
+    Q_D(QObject);
+    if (!d->threadData->eventDispatcher) {
+        qWarning("QSocketNotifier: Can only be used with threads started with QThread");
+    } else {
+        d->threadData->eventDispatcher->registerSocketNotifier(this);
+    }
+}
+
+#ifdef QT3_SUPPORT
+/*!
+    \obsolete
+
+    Use the QSocketNotifier() constructor combined with the
+    QObject::setObjectName() function instead.
+
+    \oldcode
+        QSocketNotifier *notifier = new QSocketNotifier(socket, type, parent, name);
+    \newcode
+        QSocketNotifier *notifier = new QSocketNotifier(socket, type, parent);
+        notifier->setObjectName(name);
+    \endcode
+*/
+
+QSocketNotifier::QSocketNotifier(int socket, Type type, QObject *parent,
+                                  const char *name)
+    : QObject(parent)
+{
+    setObjectName(QString::fromAscii(name));
+    if (socket < 0)
+        qWarning("QSocketNotifier: Invalid socket specified");
+    sockfd = socket;
+    sntype = type;
+    snenabled = true;
+
+    Q_D(QObject);
+    if (!d->threadData->eventDispatcher) {
+        qWarning("QSocketNotifier: Can only be used with threads started with QThread");
+    } else {
+        d->threadData->eventDispatcher->registerSocketNotifier(this);
+    }
+}
+#endif
+/*!
+    Destroys this socket notifier.
+*/
+
+QSocketNotifier::~QSocketNotifier()
+{
+    setEnabled(false);
+}
+
+
+/*!
+    \fn void QSocketNotifier::activated(int socket)
+
+    This signal is emitted whenever the socket notifier is enabled and
+    a socket event corresponding to its \l {Type}{type} occurs.
+
+    The socket identifier is passed in the \a socket parameter.
+
+    \sa type(), socket()
+*/
+
+
+/*!
+    \fn int QSocketNotifier::socket() const
+
+    Returns the socket identifier specified to the constructor.
+
+    \sa type()
+*/
+
+/*!
+    \fn Type QSocketNotifier::type() const
+
+    Returns the socket event type specified to the constructor.
+
+    \sa socket()
+*/
+
+
+/*!
+    \fn bool QSocketNotifier::isEnabled() const
+
+    Returns true if the notifier is enabled; otherwise returns false.
+
+    \sa setEnabled()
+*/
+
+/*!
+    If \a enable is true, the notifier is enabled; otherwise the notifier
+    is disabled.
+
+    The notifier is enabled by default, i.e. it emits the activated()
+    signal whenever a socket event corresponding to its
+    \l{type()}{type} occurs. If it is disabled, it ignores socket
+    events (the same effect as not creating the socket notifier).
+
+    Write notifiers should normally be disabled immediately after the
+    activated() signal has been emitted
+
+    \sa isEnabled(), activated()
+*/
+
+void QSocketNotifier::setEnabled(bool enable)
+{
+    if (sockfd < 0)
+        return;
+    if (snenabled == enable)                        // no change
+        return;
+    snenabled = enable;
+
+    Q_D(QObject);
+    if (!d->threadData->eventDispatcher) // perhaps application/thread is shutting down
+        return;
+    if (snenabled)
+        d->threadData->eventDispatcher->registerSocketNotifier(this);
+    else
+        d->threadData->eventDispatcher->unregisterSocketNotifier(this);
+}
+
+
+/*!\reimp
+*/
+bool QSocketNotifier::event(QEvent *e)
+{
+    // Emits the activated() signal when a QEvent::SockAct is
+    // received.
+    if (e->type() == QEvent::ThreadChange) {
+        if (snenabled) {
+            QMetaObject::invokeMethod(this, "setEnabled", Qt::QueuedConnection,
+                                      Q_ARG(bool, snenabled));
+            setEnabled(false);
+        }
+    }
+    QObject::event(e);                        // will activate filters
+    if (e->type() == QEvent::SockAct) {
+        emit activated(sockfd);
+        return true;
+    }
+    return false;
+}
+
+QT_END_NAMESPACE