Struct iou::SubmissionQueue

pub struct SubmissionQueue<'ring> { /* fields omitted */ }

The queue of pending IO events.

Each element is a SQE. By default, events are processed in parallel after being submitted. You can modify this behavior for specific events using event SubmissionFlags.

Examples

Consider a read event that depends on a successful write beforehand.

We reify this relationship by using IO_LINK to link these events.

let mut write_event = sq.prepare_sqe().unwrap();

// -- write event prep elided

// set IO_LINK to link the next event to this one
write_event.set_flags(SubmissionFlags::IO_LINK);

let mut read_event = sq.prepare_sqe().unwrap();

// -- read event prep elided

// read_event only occurs if write_event was successful
sq.submit()?;

Implementations

impl<'ring> SubmissionQueue<'ring>

pub fn prepare_sqe<'a>(&'a mut self) -> Option<SQE<'a>>

Returns new SQEs until the queue size is reached. After that, will return None.

let mut ring = IoUring::new(ring_size)?;

let mut counter = 0;

while let Some(event) = ring.prepare_sqe() {
    counter += 1;
}

assert_eq!(counter, ring_size);
assert!(ring.prepare_sqe().is_none());

pub fn prepare_sqes<'a>(&'a mut self, count: u32) -> Option<SQEs<'a>>

pub fn submit(&mut self) -> Result<u32>

Submit all events in the queue. Returns the number of submitted events.

If this function encounters any IO errors an io::Error variant is returned.

pub fn submit_and_wait(&mut self, wait_for: u32) -> Result<u32>

pub fn submit_and_wait_with_timeout(
    &mut self,
    wait_for: u32,
    duration: Duration
) -> Result<u32>

pub fn ready(&self) -> u32

pub fn space_left(&self) -> u32

Trait Implementations

impl<'_> Debug for SubmissionQueue<'_>

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

Formats the value using the given formatter.

impl<'ring> Send for SubmissionQueue<'ring>

impl<'ring> Sync for SubmissionQueue<'ring>