Struct SetReadiness

Source

pub struct SetReadiness { /* private fields */ }

Expand description

Updates the readiness state of the associated Registration.

See Registration for more documentation on using SetReadiness and Poll for high level polling documentation.

Implementations§

Source §

impl SetReadiness

Source

pub fn readiness(&self) -> Ready

Returns the registration’s current readiness.

§Note

There is no guarantee that readiness establishes any sort of memory ordering. Any concurrent data access must be synchronized using another strategy.

§Examples

use futures_net::driver::sys::Registration;
use futures_net::driver::sys::event::Ready;

let (registration, set_readiness) = Registration::new2();

assert!(set_readiness.readiness().is_empty());

set_readiness.set_readiness(Ready::readable())?;
assert!(set_readiness.readiness().is_readable());

Source

pub fn set_readiness(&self, ready: Ready) -> Result<()>

Set the registration’s readiness

If the associated Registration is registered with a Poll instance and has requested readiness events that include ready, then a future call to Poll::poll will receive a readiness event representing the readiness state change.

§Note

There is no guarantee that readiness establishes any sort of memory ordering. Any concurrent data access must be synchronized using another strategy.

There is also no guarantee as to when the readiness event will be delivered to poll. A best attempt will be made to make the delivery in a “timely” fashion. For example, the following is not guaranteed to work:

use futures_net::driver::sys::{Poll, Registration, Token};
use futures_net::driver::sys::event::{Events, Ready, PollOpt};

let poll = Poll::new()?;
let (registration, set_readiness) = Registration::new2();

poll.register(&registration,
              Token(0),
              Ready::readable(),
              PollOpt::edge())?;

// Set the readiness, then immediately poll to try to get the readiness
// event
set_readiness.set_readiness(Ready::readable())?;

let mut events = Events::with_capacity(1024);
poll.poll(&mut events, None)?;

// There is NO guarantee that the following will work. It is possible
// that the readiness event will be delivered at a later time.
let event = events.get(0).unwrap();
assert_eq!(event.token(), Token(0));
assert!(event.readiness().is_readable());

§Examples

A simple example, for a more elaborate example, see the Evented documentation.

use futures_net::driver::sys::Registration;
use futures_net::driver::sys::event::Ready;

let (registration, set_readiness) = Registration::new2();

assert!(set_readiness.readiness().is_empty());

set_readiness.set_readiness(Ready::readable())?;
assert!(set_readiness.readiness().is_readable());