Struct SubmissionQueue 

pub struct SubmissionQueue<'a, E: EntryMarker = Entry> { /* private fields */ }

An io_uring instance’s submission queue. This is used to send I/O requests to the kernel.

Implementations

impl<E: EntryMarker> SubmissionQueue<'_, E>

pub fn sync(&self)

Synchronize this type with the real submission queue.

This will flush any entries added by push or push_multiple and will update the queue’s length if the kernel has consumed some entries in the meantime.

pub fn need_wakeup(&self) -> bool

When is_setup_sqpoll is set, whether the kernel threads has gone to sleep and requires a system call to wake it up.

A result of false is only meaningful if the function was called after the latest update to the queue head. Other interpretations could lead to a race condition where the kernel concurrently put the device to sleep and no further progress is made.

pub fn need_wakeup_after_intermittent_seqcst(&self) -> bool

The effect of Self::need_wakeup, after synchronization work performed by the caller.

This function should only be called if the caller can guarantee that a SeqCst fence has been inserted after the last write to the queue’s head. The function is then a little more efficient by avoiding to perform one itself.

Failure to uphold the precondition can result in an effective dead-lock due to a sleeping device.

pub fn dropped(&self) -> u32

The number of invalid submission queue entries that have been encountered in the ring buffer.

pub fn cq_overflow(&self) -> bool

Returns true if the completion queue ring is overflown.

pub fn taskrun(&self) -> bool

Returns true if completions are pending that should be processed. Only relevant when used in conjuction with the setup_taskrun_flag function. Available since 5.19.

pub fn capacity(&self) -> usize

Get the total number of entries in the submission queue ring buffer.

pub fn len(&self) -> usize

Get the number of submission queue events in the ring buffer.

pub fn is_empty(&self) -> bool

Returns true if the submission queue ring buffer is empty.

pub fn is_full(&self) -> bool

Returns true if the submission queue ring buffer has reached capacity, and no more events can be added before the kernel consumes some.

pub unsafe fn push_inline<F>(&self, f: F) -> Result<(), PushError>

where F: FnOnce(&mut E),

Attempts to push an entry into the queue. If the queue is full, an error is returned.

Safety

Developers must ensure that parameters of the entry (such as buffer) are valid and will be valid for the entire duration of the operation, otherwise it may cause memory problems.

pub unsafe fn push(&self, entry: &E) -> Result<(), PushError>

Attempts to push an entry into the queue. If the queue is full, an error is returned.

Safety

Developers must ensure that parameters of the entry (such as buffer) are valid and will be valid for the entire duration of the operation, otherwise it may cause memory problems.

pub unsafe fn push_multiple(&self, entries: &[E]) -> Result<(), PushError>

Attempts to push several entries into the queue. If the queue does not have space for all of the entries, an error is returned.

Safety

Developers must ensure that parameters of all the entries (such as buffer) are valid and will be valid for the entire duration of the operation, otherwise it may cause memory problems.

Trait Implementations

impl<'a, E: Clone + EntryMarker> Clone for SubmissionQueue<'a, E>

fn clone(&self) -> SubmissionQueue<'a, E>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'a, E: EntryMarker> Copy for SubmissionQueue<'a, E>

impl<E: EntryMarker> Debug for SubmissionQueue<'_, E>

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

Formats the value using the given formatter.