Struct io_uring::squeue::Flags

pub struct Flags { /* fields omitted */ }

Submission flags

Implementations

impl Flags

pub const IO_DRAIN: Flags

When this flag is specified, the SQE will not be started before previously submitted SQEs have completed, and new SQEs will not be started before this one completes.

pub const IO_LINK: Flags

When this flag is specified, it forms a link with the next SQE in the submission ring. That next SQE will not be started before this one completes.

pub const IO_HARDLINK: Flags

Like IO_LINK, but it doesn’t sever regardless of the completion result.

pub const ASYNC: Flags

Normal operation for io_uring is to try and issue an sqe as non-blocking first, and if that fails, execute it in an async manner.

To support more efficient overlapped operation of requests that the application knows/assumes will always (or most of the time) block, the application can ask for an sqe to be issued async from the start.

pub const BUFFER_SELECT: Flags

Conceptually the kernel holds a set of buffers organized into groups. When you issue a request with this flag and set buf_group to a valid buffer group ID (e.g. buf_group on Read) then once the file descriptor becomes ready the kernel will try to take a buffer from the group.

If there are no buffers in the group, your request will fail with -ENOBUFS. Otherwise, the corresponding cqueue::Entry::flags will contain the chosen buffer ID, encoded with:

(buffer_id << IORING_CQE_BUFFER_SHIFT) | IORING_CQE_F_BUFFER

You can use buffer_select to take the buffer ID.

The buffer will then be removed from the group and won’t be usable by other requests anymore.

You can provide new buffers in a group with ProvideBuffers.

See also the LWN thread on automatic buffer selection.

Requires the unstable feature.

pub const fn empty() -> Flags

Returns an empty set of flags

pub const fn all() -> Flags

Returns the set containing all flags.

pub const fn bits(&self) -> u8

Returns the raw value of the flags currently stored.

pub fn from_bits(bits: u8) -> Option<Flags>

Convert from underlying bit representation, unless that representation contains bits that do not correspond to a flag.

pub const fn from_bits_truncate(bits: u8) -> Flags

Convert from underlying bit representation, dropping any bits that do not correspond to flags.

pub const unsafe fn from_bits_unchecked(bits: u8) -> Flags

Convert from underlying bit representation, preserving all bits (even those not corresponding to a defined flag).

pub const fn is_empty(&self) -> bool

Returns true if no flags are currently stored.

pub const fn is_all(&self) -> bool

Returns true if all flags are currently set.

pub const fn intersects(&self, other: Flags) -> bool

Returns true if there are flags common to both self and other.

pub const fn contains(&self, other: Flags) -> bool

Returns true all of the flags in other are contained within self.

pub fn insert(&mut self, other: Flags)

Inserts the specified flags in-place.

pub fn remove(&mut self, other: Flags)

Removes the specified flags in-place.

pub fn toggle(&mut self, other: Flags)

Toggles the specified flags in-place.

pub fn set(&mut self, other: Flags, value: bool)

Inserts or removes the specified flags depending on the passed value.

Trait Implementations

impl Binary for Flags

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

Formats the value using the given formatter.

impl BitAnd<Flags> for Flags

type Output = Flags

The resulting type after applying the & operator.

fn bitand(self, other: Flags) -> Flags

Returns the intersection between the two sets of flags.

impl BitAndAssign<Flags> for Flags

fn bitand_assign(&mut self, other: Flags)

Disables all flags disabled in the set.

impl BitOr<Flags> for Flags

type Output = Flags

The resulting type after applying the | operator.

fn bitor(self, other: Flags) -> Flags

Returns the union of the two sets of flags.

impl BitOrAssign<Flags> for Flags

fn bitor_assign(&mut self, other: Flags)

Adds the set of flags.

impl BitXor<Flags> for Flags

type Output = Flags

The resulting type after applying the ^ operator.

fn bitxor(self, other: Flags) -> Flags

Returns the left flags, but with all the right flags toggled.

impl BitXorAssign<Flags> for Flags

fn bitxor_assign(&mut self, other: Flags)

Toggles the set of flags.

impl Clone for Flags

fn clone(&self) -> Flags

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Copy for Flags

impl Debug for Flags

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

Formats the value using the given formatter.

impl Eq for Flags

impl Extend<Flags> for Flags

fn extend<T: IntoIterator<Item = Flags>>(&mut self, iterator: T)

Extends a collection with the contents of an iterator.

pub fn extend_one(&mut self, item: A)

🔬 This is a nightly-only experimental API. (extend_one)

Extends a collection with exactly one element.

pub fn extend_reserve(&mut self, additional: usize)

🔬 This is a nightly-only experimental API. (extend_one)

Reserves capacity in a collection for the given number of additional elements.

impl FromIterator<Flags> for Flags

fn from_iter<T: IntoIterator<Item = Flags>>(iterator: T) -> Flags

Creates a value from an iterator.

impl Hash for Flags

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

Feeds this value into the given Hasher.

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

Feeds a slice of this type into the given Hasher.

impl LowerHex for Flags

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

Formats the value using the given formatter.

impl Not for Flags

type Output = Flags

The resulting type after applying the ! operator.

fn not(self) -> Flags

Returns the complement of this set of flags.

impl Octal for Flags

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

Formats the value using the given formatter.

impl Ord for Flags

fn cmp(&self, other: &Flags) -> Ordering

This method returns an Ordering between self and other.

#[must_use]pub fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

#[must_use]pub fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

#[must_use]pub fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval.

impl PartialEq<Flags> for Flags

fn eq(&self, other: &Flags) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=.

impl PartialOrd<Flags> for Flags

fn partial_cmp(&self, other: &Flags) -> Option<Ordering>

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

#[must_use]pub fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

#[must_use]pub fn le(&self, other: &Rhs) -> bool

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

#[must_use]pub fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

#[must_use]pub fn ge(&self, other: &Rhs) -> bool

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

impl StructuralEq for Flags

impl StructuralPartialEq for Flags

impl Sub<Flags> for Flags

type Output = Flags

The resulting type after applying the - operator.

fn sub(self, other: Flags) -> Flags

Returns the set difference of the two sets of flags.

impl SubAssign<Flags> for Flags

fn sub_assign(&mut self, other: Flags)

Disables all flags enabled in the set.

impl UpperHex for Flags

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

Formats the value using the given formatter.