Struct zircon_object::ipc::Channel

pub struct Channel { /* private fields */ }

Bidirectional interprocess communication

SYNOPSIS

A channel is a bidirectional transport of messages consisting of some amount of byte data and some number of handles.

DESCRIPTION

The process of sending a message via a channel has two steps. The first is to atomically write the data into the channel and move ownership of all handles in the message into this channel. This operation always consumes the handles: at the end of the call, all handles either are all in the channel or are all discarded. The second operation, channel read, is similar: on success all the handles in the next message are atomically moved into the receiving process’ handle table. On failure, the channel retains ownership.

Implementations

impl Channel

pub fn create() -> (Arc<Self>, Arc<Self>)

Create a channel and return a pair of its endpoints

pub fn check_and_read(
    &self,
    checker: impl FnOnce(&MessagePacket) -> ZxResult
) -> ZxResult<MessagePacket>

Read a packet from the channel if check is ok, otherwise the msg will keep.

pub fn read(&self) -> ZxResult<MessagePacket>

Read a packet from the channel

pub fn write(&self, msg: MessagePacket) -> ZxResult

Write a packet to the channel

pub async fn call(
    self: &Arc<Self>,
    msg: MessagePacket
) -> ZxResult<MessagePacket>

Send a message to a channel and await a reply.

The first four bytes of the written and read back messages are treated as a transaction ID. The kernel generates a txid for the written message, replacing that part of the message as read from userspace.

msg.data must have at lease a length of 4 bytes.

Trait Implementations

impl Debug for Channel

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Drop for Channel

fn drop(&mut self)

Executes the destructor for this type.

impl KernelObject for Channel

fn id(&self) -> KoID

Get object’s KoID.

fn type_name(&self) -> &str

Get the name of the type of the kernel object.

fn name(&self) -> String

Get object’s name.

fn set_name(&self, name: &str)

Set object’s name.

fn signal(&self) -> Signal

Get the signal status.

fn signal_set(&self, signal: Signal)

Assert signal.

fn signal_clear(&self, signal: Signal)

Deassert signal.

fn signal_change(&self, clear: Signal, set: Signal)

Change signal status: first clear then set indicated bits.

fn add_signal_callback(&self, callback: SignalHandler)

Add callback for signal status changes.

fn peer(&self) -> ZxResult<Arc<dyn KernelObject>>

Attempt to get the object’s peer.

fn related_koid(&self) -> KoID

If the object is related to another (such as the other end of a channel, or the parent of a job), returns the KoID of that object, otherwise returns zero.

fn get_child(&self, _id: KoID) -> ZxResult<Arc<dyn KernelObject>>

Attempt to find a child of the object with given KoID.

fn allowed_signals(&self) -> Signal

Get object’s allowed signals.