Struct io_uring::Parameters
source · pub struct Parameters(_);
Expand description
The parameters that were used to construct an IoUring
.
Implementations§
source§impl Parameters
impl Parameters
sourcepub fn is_setup_sqpoll(&self) -> bool
pub fn is_setup_sqpoll(&self) -> bool
Whether a kernel thread is performing queue polling. Enabled with Builder::setup_sqpoll
.
sourcepub fn is_setup_iopoll(&self) -> bool
pub fn is_setup_iopoll(&self) -> bool
Whether waiting for completion events is done with a busy loop instead of using IRQs.
Enabled with Builder::setup_iopoll
.
sourcepub fn is_feature_single_mmap(&self) -> bool
pub fn is_feature_single_mmap(&self) -> bool
If this flag is set, the SQ and CQ rings were mapped with a single mmap(2)
call. This
means that only two syscalls were used instead of three.
sourcepub fn is_feature_nodrop(&self) -> bool
pub fn is_feature_nodrop(&self) -> bool
If this flag is set, io_uring supports never dropping completion events. If a completion event occurs and the CQ ring is full, the kernel stores the event internally until such a time that the CQ ring has room for more entries.
sourcepub fn is_feature_submit_stable(&self) -> bool
pub fn is_feature_submit_stable(&self) -> bool
If this flag is set, applications can be certain that any data for async offload has been consumed when the kernel has consumed the SQE.
sourcepub fn is_feature_rw_cur_pos(&self) -> bool
pub fn is_feature_rw_cur_pos(&self) -> bool
If this flag is set, applications can specify offset == -1 with Readv
,
Writev
, ReadFixed
,
WriteFixed
, Read
and Write
,
which behaves exactly like setting offset == -1 in preadv2(2)
and pwritev2(2)
: it’ll use
(and update) the current file position.
This obviously comes with the caveat that if the application has multiple reads or writes in flight, then the end result will not be as expected. This is similar to threads sharing a file descriptor and doing IO using the current file position.
sourcepub fn is_feature_cur_personality(&self) -> bool
pub fn is_feature_cur_personality(&self) -> bool
If this flag is set, then io_uring guarantees that both sync and async execution of
a request assumes the credentials of the task that called Submitter::enter
to queue the requests.
If this flag isn’t set, then requests are issued with the credentials of the task that originally registered the io_uring.
If only one task is using a ring, then this flag doesn’t matter as the credentials will always be the same.
Note that this is the default behavior, tasks can still register different personalities
through Submitter::register_personality
.
sourcepub fn is_feature_fast_poll(&self) -> bool
pub fn is_feature_fast_poll(&self) -> bool
Whether async pollable I/O is fast.
See the commit message that introduced it for more details.
sourcepub fn is_feature_poll_32bits(&self) -> bool
pub fn is_feature_poll_32bits(&self) -> bool
Whether poll events are stored using 32 bits instead of 16. This allows the user to use
EPOLLEXCLUSIVE
.
pub fn is_feature_sqpoll_nonfixed(&self) -> bool
pub fn is_feature_ext_arg(&self) -> bool
pub fn is_feature_native_workers(&self) -> bool
sourcepub fn sq_entries(&self) -> u32
pub fn sq_entries(&self) -> u32
The number of submission queue entries allocated.
sourcepub fn cq_entries(&self) -> u32
pub fn cq_entries(&self) -> u32
The number of completion queue entries allocated.
Trait Implementations§
source§impl Clone for Parameters
impl Clone for Parameters
source§fn clone(&self) -> Parameters
fn clone(&self) -> Parameters
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source
. Read more