QUnixSocketServer Class Reference

The QUnixSocketServer class provides a Unix domain socket based server. More...

#include <qunixsocketserver_p.h>

Inheritance diagram for QUnixSocketServer:

Public Types
enum	ServerError {   NoError, InvalidPath, ResourceError, BindError,   ListenError }
	The ServerError enumeration represents the errors that can occur during server establishment. More...

Public Functions
void	close ()
	Stop listening for incoming connections and resets the Unix socket server's state. More...
bool	isListening () const
	Returns true if this server is listening for incoming connections, false otherwise. More...
bool	listen (const QByteArray &path)
	Tells the server to listen for incoming connections on path. More...
int	maxPendingConnections () const
	Returns the maximum length the queue of pending connections may grow to. More...
	QUnixSocketServer (QObject *parent=0)
	Create a new Unix socket server with the given parent. More...
QByteArray	serverAddress () const
	Returns the Unix path on which this server is listening. More...
ServerError	serverError () const
	Returns the last server error. More...
void	setMaxPendingConnections (int numConnections)
	Sets the maximum length the queue of pending connections may grow to numConnections. More...
int	socketDescriptor () const
virtual	~QUnixSocketServer ()
	Stops listening for incoming connection and destroys the Unix socket server. More...
Public Functions inherited from QObject
bool	blockSignals (bool b)
	If block is true, signals emitted by this object are blocked (i.e., emitting a signal will not invoke anything connected to it). More...
const QObjectList &	children () const
	Returns a list of child objects. More...
bool	connect (const QObject *sender, const char *signal, const char *member, Qt::ConnectionType type=Qt::AutoConnection) const
bool	disconnect (const char *signal=0, const QObject *receiver=0, const char *member=0)
bool	disconnect (const QObject *receiver, const char *member=0)
void	dumpObjectInfo ()
	Dumps information about signal connections, etc. More...
void	dumpObjectTree ()
	Dumps a tree of children to the debug output. More...
QList< QByteArray >	dynamicPropertyNames () const
	Returns the names of all properties that were dynamically added to the object using setProperty(). More...
virtual bool	event (QEvent *)
	This virtual function receives events to an object and should return true if the event e was recognized and processed. More...
virtual bool	eventFilter (QObject *, QEvent *)
	Filters events if this object has been installed as an event filter for the watched object. More...
template<typename T >
T	findChild (const QString &aName=QString()) const
	Returns the child of this object that can be cast into type T and that is called name, or 0 if there is no such object. More...
template<typename T >
QList< T >	findChildren (const QString &aName=QString()) const
	Returns all children of this object with the given name that can be cast to type T, or an empty list if there are no such objects. More...
template<typename T >
QList< T >	findChildren (const QRegExp &re) const
bool	inherits (const char *classname) const
	Returns true if this object is an instance of a class that inherits className or a QObject subclass that inherits className; otherwise returns false. More...
void	installEventFilter (QObject *)
	Installs an event filter filterObj on this object. More...
bool	isWidgetType () const
	Returns true if the object is a widget; otherwise returns false. More...
void	killTimer (int id)
	Kills the timer with timer identifier, id. More...
virtual const QMetaObject *	metaObject () const
	Returns a pointer to the meta-object of this object. More...
void	moveToThread (QThread *thread)
	Changes the thread affinity for this object and its children. More...
QString	objectName () const
QObject *	parent () const
	Returns a pointer to the parent object. More...
QVariant	property (const char *name) const
	Returns the value of the object's name property. More...
Q_INVOKABLE	QObject (QObject *parent=0)
	Constructs an object with parent object parent. More...
void	removeEventFilter (QObject *)
	Removes an event filter object obj from this object. More...
void	setObjectName (const QString &name)
void	setParent (QObject *)
	Makes the object a child of parent. More...
bool	setProperty (const char *name, const QVariant &value)
	Sets the value of the object's name property to value. More...
void	setUserData (uint id, QObjectUserData *data)
bool	signalsBlocked () const
	Returns true if signals are blocked; otherwise returns false. More...
int	startTimer (int interval)
	Starts a timer and returns a timer identifier, or returns zero if it could not start a timer. More...
QThread *	thread () const
	Returns the thread in which the object lives. More...
QObjectUserData *	userData (uint id) const
virtual	~QObject ()
	Destroys the object, deleting all its child objects. More...

Protected Functions
virtual void	incomingConnection (int socketDescriptor)=0
	This method is invoked each time a new incoming connection is established with the server. More...
Protected Functions inherited from QObject
virtual void	childEvent (QChildEvent *)
	This event handler can be reimplemented in a subclass to receive child events. More...
virtual void	connectNotify (const char *signal)
	This virtual function is called when something has been connected to signal in this object. More...
virtual void	customEvent (QEvent *)
	This event handler can be reimplemented in a subclass to receive custom events. More...
virtual void	disconnectNotify (const char *signal)
	This virtual function is called when something has been disconnected from signal in this object. More...
	QObject (QObjectPrivate &dd, QObject *parent=0)
int	receivers (const char *signal) const
	Returns the number of receivers connected to the signal. More...
QObject *	sender () const
	Returns a pointer to the object that sent the signal, if called in a slot activated by a signal; otherwise it returns 0. More...
int	senderSignalIndex () const
virtual void	timerEvent (QTimerEvent *)
	This event handler can be reimplemented in a subclass to receive timer events for the object. More...

Private Functions
QUnixSocketServer &	operator= (const QUnixSocketServer &)
	QUnixSocketServer (const QUnixSocketServer &)

Properties
QUnixSocketServerPrivate *	d

Friends
class	QUnixSocketServerPrivate

Additional Inherited Members
Public Slots inherited from QObject
void	deleteLater ()
	Schedules this object for deletion. More...
Signals inherited from QObject
void	destroyed (QObject *=0)
	This signal is emitted immediately before the object obj is destroyed, and can not be blocked. More...
Static Public Functions inherited from QObject
static bool	connect (const QObject *sender, const char *signal, const QObject *receiver, const char *member, Qt::ConnectionType=Qt::AutoConnection)
	Creates a connection of the given type from the signal in the sender object to the method in the receiver object. More...
static bool	connect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &method, Qt::ConnectionType type=Qt::AutoConnection)
static bool	disconnect (const QObject *sender, const char *signal, const QObject *receiver, const char *member)
	Disconnects signal in object sender from method in object receiver. More...
static bool	disconnect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &member)
static uint	registerUserData ()
static QString	tr (const char *sourceText, const char *comment=0, int n=-1)
static QString	trUtf8 (const char *sourceText, const char *comment=0, int n=-1)
Static Public Variables inherited from QObject
static const QMetaObject	staticMetaObject
	This variable stores the meta-object for the class. More...
Protected Variables inherited from QObject
QScopedPointer< QObjectData >	d_ptr
Static Protected Variables inherited from QObject
static const QMetaObject	staticQtMetaObject
Related Functions inherited from QObject
T	qFindChildqFindChildren (const QObject *obj, const QString &name)()
QList< T >	qFindChildrenqFindChildren (const QObject *obj, const QString &name)()
QList< T >	qFindChildrenqFindChildren (const QObject *obj, const QRegExp &regExp)()
T *	qobject_cast (QObject *object)
	QObjectList
void *	qt_find_obj_child (QObject *parent, const char *type, const QString &name)
	Returns a pointer to the object named name that inherits type and with a given parent. More...

Detailed Description

The QUnixSocketServer class provides a Unix domain socket based server.

Warning

This function is not part of the public interface.

This function is not part of the public interface. :: :: ::

This class makes it possible to accept incoming Unix domain socket connections. Call QUnixSocketServer::listen() to have the server listen for incoming connections on a specified path. The pure virtual QUnixSocketServer::incomingConnection() is called each time a new connection is established. Users must inherit from QUnixSocketServer and implement this method.

If an error occurs, QUnixSocketServer::serverError() returns the type of error. Errors can only occur during server establishment - that is, during a call to QUnixSocketServer::listen() . Calling QUnixSocketServer::close() causes QUnixSocketServer to stop listening for connections and reset its state.

QUnixSocketServer is often used in conjunction with the QUnixSocket class.

See also

QUnixSocket

Definition at line 61 of file qunixsocketserver_p.h.

Enumerations

ServerError

enum QUnixSocketServer::ServerError

The ServerError enumeration represents the errors that can occur during server establishment.

The most recent error can be retrieved through a call to QUnixSocketServer::serverError() .

• NoError No error has occurred.
• InvalidPath An invalid path endpoint was passed to QUnixSocketServer::listen() . As defined by unix(7), invalid paths include an empty path, or what more than 107 characters long.
• ResourceError An error acquiring or manipulating the system's socket resources occurred. For example, if the process runs out of available socket descriptors, a ResourceError will occur.
• BindError The server was unable to bind to the specified path.
• ListenError The server was unable to listen on the specified path for incoming connections.

Enumerator
NoError
InvalidPath
ResourceError
BindError
ListenError

Definition at line 65 of file qunixsocketserver_p.h.

                     { NoError, InvalidPath, ResourceError, BindError,
                       ListenError };

Constructors and Destructors

QUnixSocketServer() [1/2]

QUnixSocketServer::QUnixSocketServer

(

QObject *

parent = 0

)

Create a new Unix socket server with the given parent.

Definition at line 141 of file qunixsocketserver.cpp.

: QObject(parent), d(0)
{
}

~QUnixSocketServer()

QUnixSocketServer::~QUnixSocketServer ( )

virtual

Stops listening for incoming connection and destroys the Unix socket server.

Definition at line 149 of file qunixsocketserver.cpp.

{
    close();
    if(d)
        delete d;
}

QUnixSocketServer() [2/2]

QUnixSocketServer::QUnixSocketServer ( const QUnixSocketServer &  )

private

Functions

close()

void QUnixSocketServer::close

(

)

Stop listening for incoming connections and resets the Unix socket server's state.

Calling this method while QUnixSocketServer::isListening(){not listening } for incoming connections is a no-op.

See also

QUnixSocketServer::listen()

Definition at line 162 of file qunixsocketserver.cpp.

Referenced by listen(), and ~QUnixSocketServer().

{
    if(!d)
        return;

    if(d->acceptNotifier) {
        d->acceptNotifier->setEnabled(false);
        delete d->acceptNotifier;
    }
    d->acceptNotifier = 0;

    if(-1 != d->fd) {
#ifdef QUNIXSOCKET_DEBUG
        int closerv =
#endif
            ::close(d->fd);
#ifdef QUNIXSOCKET_DEBUG
        if(0 != closerv) {
            qDebug() << "QUnixSocketServer: Unable to close socket ("
                     << strerror(errno) << ')';
        }
#endif
    }
    d->fd = -1;
    d->address = QByteArray();
    d->error = NoError;
}

incomingConnection()

void QUnixSocketServer::incomingConnection ( int  socketDescriptor )

protectedpure virtual

This method is invoked each time a new incoming connection is established with the server.

Clients must reimplement this function in their QUnixSocketServer derived class to handle the connection.

A common approach to handling the connection is to pass socketDescriptor to a QUnixSocket instance.

See also

QUnixSocket

isListening()

bool QUnixSocketServer::isListening

(

)

const

Returns true if this server is listening for incoming connections, false otherwise.

See also

QUnixSocketServer::listen()

Definition at line 213 of file qunixsocketserver.cpp.

{
    if(!d)
        return false;

    return (-1 != d->fd);
}

listen()

bool QUnixSocketServer::listen

(

const QByteArray &

path

)

Tells the server to listen for incoming connections on path.

Returns true if it successfully initializes, false otherwise. In the case of failure, the QUnixSocketServer::serverError() error status is set accordingly.

Calling this method while the server is already running will result in the server begin reset, and then attempting to listen on path. This will not affect connections established prior to the server being reset, but further incoming connections on the previous path will be refused.

The server can be explicitly reset by a call to QUnixSocketServer::close() .

See also

QUnixSocketServer::close()

Definition at line 235 of file qunixsocketserver.cpp.

Referenced by QWSServerSocket::init().

{
    if(d) {
        close(); // Any existing server is destroyed
    } else {
        d = new QUnixSocketServerPrivate(this);
    }

    if(path.isEmpty() || path.size() > UNIX_PATH_MAX) {
        d->error = InvalidPath;
        return false;
    }
    unlink( path );  // ok if this fails

    // Create the socket
    d->fd = ::socket(PF_UNIX, SOCK_STREAM, 0);
    if(-1 == d->fd) {
#ifdef QUNIXSOCKETSERVER_DEBUG
        qDebug() << "QUnixSocketServer: Unable to create socket ("
                 << strerror(errno) << ')';
#endif
        close();
        d->error = ResourceError;
        return false;
    }

    // Construct our unix address
    struct ::sockaddr_un addr;
    addr.sun_family = AF_UNIX;
    ::memcpy(addr.sun_path, path.data(), path.size());
    if(path.size() < UNIX_PATH_MAX)
        addr.sun_path[path.size()] = '\0';

    // Attempt to bind
    if(-1 == ::bind(d->fd, (sockaddr *)&addr, sizeof(sockaddr_un))) {
#ifdef QUNIXSOCKETSERVER_DEBUG
        qDebug() << "QUnixSocketServer: Unable to bind socket ("
                 << strerror(errno) << ')';
#endif
        close();
        d->error = BindError;
        return false;
    }

    // Listen to socket
    if(-1 == ::listen(d->fd, d->maxConns)) {
#ifdef QUNIXSOCKETSERVER_DEBUG
        qDebug() << "QUnixSocketServer: Unable to listen socket ("
                 << strerror(errno) << ')';
#endif
        close();
        d->error = ListenError;
        return false;
    }

    // Success!
    d->address = path;
    d->acceptNotifier = new QSocketNotifier(d->fd, QSocketNotifier::Read, d);
    d->acceptNotifier->setEnabled(true);
    QObject::connect(d->acceptNotifier, SIGNAL(activated(int)),
                     d, SLOT(acceptActivated()));

    return true;
}

maxPendingConnections()

int QUnixSocketServer::maxPendingConnections

(

)

const

Returns the maximum length the queue of pending connections may grow to.

That is, the maximum number of clients attempting to connect for which the Unix socket server has not yet accepted and passed to QUnixSocketServer::incomingConnection() . If a connection request arrives with the queue full, the client may receive a connection refused notification.

By default a queue length of 30 is used.

See also

QUnixSocketServer::setMaxPendingConnections()

Definition at line 330 of file qunixsocketserver.cpp.

{
    if(!d)
        return 30;

    return d->maxConns;
}

operator=()

QUnixSocketServer& QUnixSocketServer::operator= ( const QUnixSocketServer &  )

private

serverAddress()

QByteArray QUnixSocketServer::serverAddress

(

)

const

Returns the Unix path on which this server is listening.

If this server is not listening, and empty address will be returned.

Definition at line 304 of file qunixsocketserver.cpp.

{
    if(!d)
        return QByteArray();
    return d->address;
}

serverError()

QUnixSocketServer::ServerError QUnixSocketServer::serverError

(

)

const

Returns the last server error.

Errors may only occur within a call to QUnixSocketServer::listen() , and only when such a call fails.

This method is not destructive, so multiple calls to QUnixSocketServer::serverError() will return the same value. The error is only reset by an explicit call to QUnixSocketServer::close() or by further calls to QUnixSocketServer::listen() .

Definition at line 199 of file qunixsocketserver.cpp.

{
    if(!d)
        return NoError;

    return d->error;
}

setMaxPendingConnections()

void QUnixSocketServer::setMaxPendingConnections

(

int

numConnections

)

Sets the maximum length the queue of pending connections may grow to numConnections.

This value will only apply to QUnixSocketServer::listen() calls made following the value change - it will not be retroactively applied.

See also

QUnixSocketServer::maxPendingConnections()

Definition at line 346 of file qunixsocketserver.cpp.

{
    Q_ASSERT(numConnections >= 1);
    if(!d)
        d = new QUnixSocketServerPrivate(this);

    d->maxConns = numConnections;
}

socketDescriptor()

int QUnixSocketServer::socketDescriptor

(

)

const

Definition at line 311 of file qunixsocketserver.cpp.

{
    if (!d)
        return -1;
    return d->fd;
}

Friends and Related Functions

QUnixSocketServerPrivate

friend class QUnixSocketServerPrivate

friend

Definition at line 91 of file qunixsocketserver_p.h.

Referenced by listen(), and setMaxPendingConnections().

Properties

d

QUnixSocketServerPrivate* QUnixSocketServer::d

private

Definition at line 92 of file qunixsocketserver_p.h.

Referenced by close(), isListening(), listen(), maxPendingConnections(), serverAddress(), serverError(), setMaxPendingConnections(), socketDescriptor(), and ~QUnixSocketServer().

---

The documentation for this class was generated from the following files:

• /src/gui/embedded/qunixsocketserver_p.h
• /src/gui/embedded/qunixsocketserver.cpp