Struct Fifo

pub struct Fifo<R = UnspecifiedFifoElement, W = R>(/* private fields */);

An object representing a Zircon fifo.

As essentially a subtype of Handle, it can be freely interconverted.

Encodes the element type in the type. Defaults to () for the entry type to allow for untyped IPC. Use Fifo::cast() to convert an IPC-transferred fifo to one of the specific type required that will support reads and writes.

Implementations

impl<R, W> Fifo<R, W>

where R: IntoBytes + FromBytes, W: IntoBytes + FromBytes,

pub fn create(elem_count: usize) -> Result<(Fifo<R, W>, Fifo<W, R>), Status>

Create a pair of fifos and return their endpoints. Writing to one endpoint enqueues an element into the fifo from which the opposing endpoint reads.

Wraps the zx_fifo_create syscall.

pub fn write(&self, buf: &[W]) -> Result<usize, Status>

Attempts to write some number of elements into the fifo. On success, returns the number of elements actually written.

Wraps zx_fifo_write.

pub fn write_one(&self, elem: &W) -> Result<(), Status>

Attempts to write a single element into the fifo.

Wraps zx_fifo_write.

pub unsafe fn write_raw( &self, buf: *const W, count: usize, ) -> Result<usize, Status>

Attempts to write some number of elements into the fifo. On success, returns the number of elements actually written.

Wraps zx_fifo_write.

Safety

The caller is responsible for ensuring buf is valid to write to for count elements.

pub fn read(&self, buf: &mut [R]) -> Result<usize, Status>

Attempts to read some elements out of the fifo. On success, returns the number of elements actually read.

Wraps zx_fifo_read.

pub fn read_one(&self) -> Result<R, Status>

Attempts to read a single element out of the fifo.

Wraps zx_fifo_read.

pub fn read_uninit( &self, bytes: &mut [MaybeUninit<R>], ) -> Result<&mut [R], Status>

Attempts to read some number of elements out of the fifo. On success, returns a slice of initialized elements.

Wraps zx_fifo_read.

pub unsafe fn read_raw( &self, buf: *mut R, count: usize, ) -> Result<usize, Status>

Attempts to read some number of elements out of the fifo. On success, returns the number of elements actually read.

Wraps zx_fifo_read.

Safety

The caller is responsible for ensuring bytes points to valid (albeit not necessarily initialized) memory at least len bytes long.

impl Fifo

pub fn cast<R2, W2>(self) -> Fifo<R2, W2>

Give a Fifo specific read/write types. The size of R2 and W2 must match the element size the underlying handle was created with for reads and writes to succeed.

impl<R, W> Fifo<R, W>

pub fn downcast(self) -> Fifo

Convert a fifo from having a specific element type to a fifo without any element type that will not support reads or writes.

Trait Implementations

impl<R, W> AsHandleRef for Fifo<R, W>

fn as_handle_ref(&self) -> Unowned<'_, Handle>

Get a reference to the handle. One important use of such a reference is for object_wait_many.

fn raw_handle(&self) -> u32

Interpret the reference as a raw handle (an integer type). Two distinct handles will have different raw values (so it can perhaps be used as a key in a data structure).

fn signal_handle( &self, clear_mask: Signals, set_mask: Signals, ) -> Result<(), Status>

Set and clear userspace-accessible signal bits on an object. Wraps the zx_object_signal syscall.

fn wait_handle( &self, signals: Signals, deadline: Instant<MonotonicTimeline>, ) -> Result<Signals, Status>

Waits on a handle. Wraps the zx_object_wait_one syscall.

fn wait_async_handle( &self, port: &Port, key: u64, signals: Signals, options: WaitAsyncOpts, ) -> Result<(), Status>

Causes packet delivery on the given port when the object changes state and matches signals. zx_object_wait_async syscall.

fn get_name(&self) -> Result<Name, Status>

Get the Property::NAME property for this object.

fn set_name(&self, name: &Name) -> Result<(), Status>

Set the Property::NAME property for this object.

fn basic_info(&self) -> Result<HandleBasicInfo, Status>

Wraps the zx_object_get_info syscall for the ZX_INFO_HANDLE_BASIC topic.

fn count_info(&self) -> Result<HandleCountInfo, Status>

Wraps the zx_object_get_info syscall for the ZX_INFO_HANDLE_COUNT topic.

fn get_koid(&self) -> Result<Koid, Status>

Returns the koid (kernel object ID) for this handle.

impl<R, W> Debug for Fifo<R, W>

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

Formats the value using the given formatter.

impl<R, W> From<Fifo<R, W>> for Fifo<R, W>

fn from(fifo: Fifo<R, W>) -> Fifo<R, W>

Converts to this type from the input type.

impl<R, W> From<Fifo<R, W>> for Handle

fn from(x: Fifo<R, W>) -> Handle

Converts to this type from the input type.

impl<R, W> From<Fifo> for Fifo<R, W>

where R: FromBytes + IntoBytes, W: FromBytes + IntoBytes,

fn from(untyped: Fifo) -> Fifo<R, W>

Converts to this type from the input type.

impl<R, W> From<Handle> for Fifo<R, W>

fn from(handle: Handle) -> Fifo<R, W>

Converts to this type from the input type.

impl<R, W> HandleBased for Fifo<R, W>

fn duplicate_handle(&self, rights: Rights) -> Result<Self, Status>

Duplicate a handle, possibly reducing the rights available. Wraps the zx_handle_duplicate syscall.

fn replace_handle(self, rights: Rights) -> Result<Self, Status>

Create a replacement for a handle, possibly reducing the rights available. This invalidates the original handle. Wraps the zx_handle_replace syscall.

fn into_handle(self) -> Handle

Converts the value into its inner handle.

fn into_raw(self) -> u32

Converts the handle into it’s raw representation.

fn from_handle(handle: Handle) -> Self

Creates an instance of this type from a handle.

fn into_handle_based<H>(self) -> H

where H: HandleBased,

Creates an instance of another handle-based type from this value’s inner handle.

fn from_handle_based<H>(h: H) -> Self

where H: HandleBased,

Creates an instance of this type from the inner handle of another handle-based type.

fn is_invalid_handle(&self) -> bool

impl<R, W> Hash for Fifo<R, W>

fn hash<H>(&self, state: &mut H)

where H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<R, W> Ord for Fifo<R, W>

fn cmp(&self, other: &Fifo<R, W>) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl<R, W> PartialEq for Fifo<R, W>

fn eq(&self, other: &Fifo<R, W>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<R, W> PartialOrd for Fifo<R, W>

fn partial_cmp(&self, other: &Fifo<R, W>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl<R, W> Eq for Fifo<R, W>