Struct CoreRingManager 

pub struct CoreRingManager { /* private fields */ }

Per-core io_uring manager.

Manages a single core’s io_uring instance, buffer pool, and pending operations. Designed for integration with the thread-per-core architecture.

Implementations

impl CoreRingManager

pub fn new(core_id: usize, config: &IoUringConfig) -> Result<Self, IoUringError>

Create a new per-core ring manager.

Arguments

• core_id - The core ID this manager is for
• config - io_uring configuration

Errors

Returns an error if ring creation fails.

pub const fn core_id(&self) -> usize

Get the core ID.

pub const fn is_closed(&self) -> bool

Check if the ring is closed.

pub const fn mode(&self) -> RingMode

Get the main ring mode.

pub const fn uses_sqpoll(&self) -> bool

Check if SQPOLL is enabled.

pub fn has_iopoll_ring(&self) -> bool

Check if IOPOLL is enabled.

pub fn acquire_buffer(&mut self) -> Result<(u16, &mut [u8]), IoUringError>

Acquire a buffer from the main pool.

Errors

Returns an error if no buffers are available.

pub fn release_buffer(&mut self, buf_index: u16)

Release a buffer back to the main pool.

pub fn submit_read( &mut self, fd: RawFd, buf_index: u16, offset: u64, len: u32, ) -> Result<u64, IoUringError>

Submit a read operation using a registered buffer.

Errors

Returns an error if submission fails.

pub fn submit_write( &mut self, fd: RawFd, buf_index: u16, offset: u64, len: u32, ) -> Result<u64, IoUringError>

Submit a write operation using a registered buffer.

Errors

Returns an error if submission fails.

pub fn submit_sync( &mut self, fd: RawFd, datasync: bool, ) -> Result<u64, IoUringError>

Submit an fsync/fdatasync operation.

Arguments

• fd - File descriptor to sync
• datasync - If true, use fdatasync (don’t sync metadata)

Errors

Returns an error if submission fails.

pub fn submit_close(&mut self, fd: RawFd) -> Result<u64, IoUringError>

Submit a close operation.

Errors

Returns an error if submission fails.

pub fn submit(&mut self) -> Result<usize, IoUringError>

Submit pending operations to the kernel.

In SQPOLL mode, this is often a no-op since the kernel polls automatically.

Errors

Returns an error if submission fails.

pub fn submit_and_wait(&mut self, want: usize) -> Result<usize, IoUringError>

Submit and wait for at least one completion.

Errors

Returns an error if submission or wait fails.

pub fn poll_completions(&mut self) -> Vec<Completion>

Poll for completions without blocking.

Returns all available completions from both rings. Allocates a Vec per call — prefer Self::poll_completions_into on hot paths.

pub fn poll_completions_into(&mut self, out: &mut Vec<Completion>)

Poll for completions into a caller-provided buffer. Zero-alloc.

Appends completions to out. The caller should clear out between iterations to reuse capacity. Uses an internal scratch buffer for CQE data collection (pre-allocated at ring creation).

pub fn wait_for(&mut self, user_data: u64) -> Result<Completion, IoUringError>

Wait for a specific operation to complete.

Errors

Returns an error if the operation is not found or wait fails.

pub fn pending_count(&self) -> usize

Get the number of pending operations.

pub fn buffer_pool_stats(&self) -> Option<BufferPoolStats>

Get buffer pool statistics.

pub const fn metrics(&self) -> &RingMetrics

Get ring metrics.

pub fn close(&mut self)

Close the ring manager.

Drains all pending operations before closing to prevent in-flight operations from accessing freed memory.

Trait Implementations

impl Debug for CoreRingManager

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

Formats the value using the given formatter.

impl Drop for CoreRingManager

fn drop(&mut self)

Executes the destructor for this type.