Struct zircon_object::ipc::Fifo

pub struct Fifo { /* private fields */ }

First-In First-Out inter-process queue.

SYNOPSIS

FIFOs are intended to be the control plane for shared memory transports. Their read and write operations are more efficient than sockets or channels, but there are severe restrictions on the size of elements and buffers.

Implementations

impl Fifo

pub fn create(elem_count: usize, elem_size: usize) -> (Arc<Self>, Arc<Self>)

Create a FIFO.

pub fn write(&self, elem_size: usize, data: &[u8], count: usize) -> ZxResult<usize>

Write data to the FIFO.

This attempts to write up to count elements (count * elem_size bytes) from data to the fifo.

Fewer elements may be written than requested if there is insufficient room in the fifo to contain all of them.

The number of elements actually written is returned.

count must be nonzero.

pub fn read(
    &self,
    elem_size: usize,
    data: &mut [u8],
    count: usize
) -> ZxResult<usize>

Read data from the FIFO.

This attempts to read up to count elements from the fifo into data.

Fewer elements may be read than requested if there are insufficient elements in the fifo to fulfill the entire request. The number of elements actually read is returned.

The elem_size must match the element size that was passed into Fifo::create().

data must have a size of count * elem_size bytes.

count must be nonzero.

Trait Implementations

impl Debug for Fifo

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

Formats the value using the given formatter.

impl Drop for Fifo

fn drop(&mut self)

Executes the destructor for this type.

impl KernelObject for Fifo

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.