--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/corelib/kernel/qsocketnotifier.cpp Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,323 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 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