Struct std::sync::mpmc::list::Channel

pub(crate) struct Channel<T> {
    head: CachePadded<Position<T>>,
    tail: CachePadded<Position<T>>,
    receivers: SyncWaker,
    _marker: PhantomData<T>,
}

Unbounded channel implemented as a linked list.

Each message sent into the channel is assigned a sequence number, i.e. an index. Indices are represented as numbers of type usize and wrap on overflow.

Consecutive messages are grouped into blocks in order to put less pressure on the allocator and improve cache efficiency.

Fields

head: CachePadded<Position<T>>

The head of the channel.

tail: CachePadded<Position<T>>

The tail of the channel.

receivers: SyncWaker

Receivers waiting while the channel is empty and not disconnected.

_marker: PhantomData<T>

Indicates that dropping a Channel<T> may drop messages of type T.

Implementations

impl<T> Channel<T>

pub(crate) fn new() -> Self

Creates a new unbounded channel.

fn start_send(&self, token: &mut Token) -> bool

Attempts to reserve a slot for sending a message.

pub(crate) unsafe fn write(&self, token: &mut Token, msg: T) -> Result<(), T>

Writes a message into the channel.

fn start_recv(&self, token: &mut Token) -> bool

Attempts to reserve a slot for receiving a message.

pub(crate) unsafe fn read(&self, token: &mut Token) -> Result<T, ()>

Reads a message from the channel.

pub(crate) fn try_send(&self, msg: T) -> Result<(), TrySendError<T>>

Attempts to send a message into the channel.

pub(crate) fn send( &self, msg: T, _deadline: Option<Instant> ) -> Result<(), SendTimeoutError<T>>

Sends a message into the channel.

pub(crate) fn try_recv(&self) -> Result<T, TryRecvError>

Attempts to receive a message without blocking.

pub(crate) fn recv( &self, deadline: Option<Instant> ) -> Result<T, RecvTimeoutError>

Receives a message from the channel.

pub(crate) fn len(&self) -> usize

Returns the current number of messages inside the channel.

pub(crate) fn capacity(&self) -> Option<usize>

Returns the capacity of the channel.

pub(crate) fn disconnect_senders(&self) -> bool

Disconnects senders and wakes up all blocked receivers.

Returns true if this call disconnected the channel.

pub(crate) fn disconnect_receivers(&self) -> bool

Disconnects receivers.

Returns true if this call disconnected the channel.

fn discard_all_messages(&self)

Discards all messages.

This method should only be called when all receivers are dropped.

pub(crate) fn is_disconnected(&self) -> bool

Returns true if the channel is disconnected.

pub(crate) fn is_empty(&self) -> bool

Returns true if the channel is empty.

pub(crate) fn is_full(&self) -> bool

Returns true if the channel is full.

Trait Implementations

impl<T> Drop for Channel<T>

fn drop(&mut self)

Executes the destructor for this type.