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Description
A GSocketControlMessage is a special-purpose utility message that can be sent to or received from a GSocket. These types of messages are often called "ancillary data".
The message can represent some sort of special instruction to or information from the socket or can represent a special kind of transfer to the peer (for example, sending a file descriptor over a UNIX socket).
These messages are sent with g_socket_send_message() and received
with g_socket_receive_message().
To extend the set of control message that can be sent, subclass this class and override the get_size, get_level, get_type and serialize methods.
To extend the set of control messages that can be received, subclass
this class and implement the deserialize method. Also, make sure your
class is registered with the GType typesystem before calling
g_socket_receive_message() to read such a message.
Functions
g_socket_control_message_deserialize ()
GSocketControlMessage * g_socket_control_message_deserialize (int level,int type,gsize size,gpointer data);
Tries to deserialize a socket control message of a given
level
and type
. This will ask all known (to GType) subclasses
of GSocketControlMessage if they can understand this kind
of message and if so deserialize it into a GSocketControlMessage.
If there is no implementation for this kind of control message, NULL
will be returned.
Parameters
level |
a socket level |
|
type |
a socket control message type for the given |
|
size |
the size of the data in bytes |
|
data |
pointer to the message data. |
[array length=size][element-type guint8] |
Since 2.22
g_socket_control_message_get_level ()
int
g_socket_control_message_get_level (GSocketControlMessage *message);
Returns the "level" (i.e. the originating protocol) of the control message. This is often SOL_SOCKET.
Since 2.22
g_socket_control_message_get_msg_type ()
int
g_socket_control_message_get_msg_type (GSocketControlMessage *message);
Returns the protocol specific type of the control message. For instance, for UNIX fd passing this would be SCM_RIGHTS.
Since 2.22
g_socket_control_message_get_size ()
gsize
g_socket_control_message_get_size (GSocketControlMessage *message);
Returns the space required for the control message, not including headers or alignment.
Since 2.22
g_socket_control_message_serialize ()
void g_socket_control_message_serialize (GSocketControlMessage *message,gpointer data);
Converts the data in the message to bytes placed in the message.
data
is guaranteed to have enough space to fit the size
returned by g_socket_control_message_get_size() on this
object.
Since 2.22
Types and Values
GSocketControlMessage
typedef struct _GSocketControlMessage GSocketControlMessage;
Base class for socket-type specific control messages that can be sent and received over GSocket.