class Session
Defined at line 7614 of file fidling/gen/sdk/fidl/fuchsia.hardware.network/fuchsia.hardware.network/hlcpp/fuchsia/hardware/network/cpp/fidl.h
Represents a session with a Network device.
A session has a data plane and a control plane. The `Session` protocol
represents the control plane of the session and the FIFOs and VMOs exchanged
during the [`Device.OpenSession`] call are the data plane. Lifetime of the
session is controlled by a `Session` protocol handle.
Sessions must attach to ports of interest to start receiving and sending
data. Sessions are always created with no ports attached.
If a port is destroyed from the underlying device, it is automatically
detached from the session.
Inbound traffic is dispatched to all open sessions. Devices typically
operate with a single primary session, see [`SessionFlags.PRIMARY`]. Each
additional open session to the same device causes data copy overhead on the
device's data path.
The session is closed with an error epitaph if an invalid buffer descriptor
is sent over either the tx or rx FIFOs. Invalid descriptors include:
- Descriptor index larger than [`SessionInfo.descriptor_count`].
- Descriptor chains larger than [`MAX_DESCRIPTOR_CHAIN`].
- rx buffers smaller than [`Info.min_rx_buffer_length`].
- tx buffers smaller than [`Info.min_tx_buffer_length`].
- tx buffers not respecting [`Info.min_tx_buffer_head`] or
[`Info.min_tx_buffer_tail`].
Public Methods
void ~Session ()void Attach (::fuchsia::hardware::network::PortId port, ::std::vector< ::fuchsia::hardware::network::FrameType> rx_frames, AttachCallback callback)Attaches the session to `port`.
Once attached, the session starts to receive the subscribed frames over
the data FIFOs and it may send frames destined to the specified `port`.
+ request `port` port to subscribe to.
+ request `rx_frames` Frame types of interest on the port.
* error `ZX_ERR_NOT_FOUND` if `port` is not valid.
* error `ZX_ERR_INVALID_ARGS` if `rx_frames` is not a subset of the
port's supported frames.
* error `ZX_ERR_ALREADY_BOUND` if `port` is already attached.
void Detach (::fuchsia::hardware::network::PortId port, DetachCallback callback)Detaches the session from `port`.
Once detached, the session stops receiving frames from `port`. Frames
sent to a detached port may be returned with an error. It is not
necessary to call `Detach` on ports that are removed from the device,
doing so causes `ZX_ERR_NOT_FOUND` to be returned.
+ request `port` port to subscribe to.
* error `ZX_ERR_NOT_FOUND` if the session is not currently attached to
the port.
void Close ()Cleanly closes a session.
This will cause the session to send a `ZX_ERR_CANCELLED` epitaph and
proceed to close the Session channel. Clients may only assume that they
own all the buffers that are currently owned by the session (sent over
either the rx or tx FIFOs) once the epitaph is received. Closing the rx
or tx FIFO is equivalent to calling `Close`.
void WatchDelegatedRxLease (WatchDelegatedRxLeaseCallback callback)Watchers for delegated receive wakeup leases.
Calls block until a lease is delegated by the device. If a call to
`WatchDelegatedRxLease` is made while a previous call is blocking, the
session is closed with `ZX_ERR_BAD_STATE`. Will never yield any values
for sessions created without [`SessionFlags.RECEIVE_RX_POWER_LEASES`].
Given a single lease is assumed sufficient to keep the system awake, the
server only keeps a single lease in its buffer. If a new delegated lease
becomes available and the client hasn't popped the previous one with a
call to `WatchDelegatedRxLease`, the server drops the previously pending
lease.
See [`DelegatedRxLease`] for how to handle delegated leases.