Struct Snapshot 

#[non_exhaustive]
pub struct Snapshot {

    pub rx_datagrams: u64,
    pub rx_receives: u64,
    pub rx_enobufs: u64,
    pub rx_exhausted: u64,
    pub tx_datagrams: u64,
    pub tx_sends: u64,
    pub tx_stalls: u64,
    pub submissions: u64,
    pub completions: u64,
    pub enters: u64,
    pub parks: u64,
    pub wakes: u64,
    pub timers_armed: u64,
    pub timers_fired: u64,
    pub timers_cancelled: u64,
}

A reading of one worker’s counters, all cumulative since it started.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

rx_datagrams: u64

UDP datagrams received, counting each UDP_GRO coalesced segment.

rx_receives: u64

Receive completions that delivered datagrams. rx_datagrams over this is the GRO coalescing actually achieved.

rx_enobufs: u64

Receives the kernel ended with ENOBUFS: the provided-buffer ring was empty, so no buffer could be selected and the receive was never performed. The datagram stays in the socket queue, so this is receive-side backpressure rather than a confirmed loss; sustained, it becomes one, once the socket buffer fills. The first thing to look at when throughput sags.

rx_exhausted: u64

Re-arms that found no free receive buffer at all, so the socket was left unarmed until a packet released one. The pool is at its ceiling and every buffer is held by an unread packet.

tx_datagrams: u64

UDP datagrams sent, counting each UDP_SEGMENT segment of a GSO train.

tx_sends: u64

sendmsg operations staged. tx_datagrams over this is the GSO batching actually achieved.

tx_stalls: u64

Times the send-buffer pool became drained at its ceiling and an acquisition had to wait. Send-side backpressure.

submissions: u64

Submission queue entries the kernel accepted.

completions: u64

Completion queue entries dispatched.

enters: u64

io_uring_enter calls. Datagrams over this is the syscall amortization the runtime exists for.

parks: u64

Times the worker parked in io_uring_enter with nothing left to poll.

wakes: u64

futex wakes another thread had to issue because the worker was parked.

timers_armed: u64

Timers armed, re-arms included (a re-arm is a cancel plus an arm).

timers_fired: u64

Timers that reached their deadline.

timers_cancelled: u64

Timers dropped or re-armed before their deadline.

Implementations

impl Snapshot

pub fn timers_active(&self) -> u64

Timers currently in the heap: armed, less those fired and cancelled.

Trait Implementations

impl Clone for Snapshot

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Snapshot

impl Debug for Snapshot

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

Formats the value using the given formatter.

impl Default for Snapshot

fn default() -> Self

Returns the “default value” for a type.

impl Eq for Snapshot

impl PartialEq for Snapshot

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Snapshot