Enum MissingStatsReason 

#[non_exhaustive]
pub enum MissingStatsReason {
    NoSchedulerBinary,
    NoScheduler {
        reason: String,
    },
    DuringFreeze,
    Cancelled,
    SchedulerError {
        errno: i32,
        args: Value,
    },
    MissingResp {
        args: Value,
    },
    RequestTooLarge {
        size: usize,
        max: usize,
    },
    ResponseTooLarge {
        size: usize,
        max: usize,
    },
    MutexPoisoned,
}

Why a sample’s stats slot is unavailable — carried on SnapshotError::MissingStats so operator diagnostics name the specific failure mode rather than the generic “stats absent”. Built by From<&crate::vmm::sched_stats::SchedStatsError> for the relay-failure path, plus dedicated variants for the pre-client gates that the crate::vmm::SchedStatsError enum doesn’t cover (no scheduler binary configured).

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

NoSchedulerBinary

No scheduler_binary was configured on the run, so the freeze coordinator never wired a crate::vmm::SchedStatsClient. Every periodic sample bypasses the stats request entirely and lands here.

NoScheduler

The guest relay never connected to the scheduler’s Unix socket (no scheduler running, or the scheduler refused the connection).

Fields

reason: String

DuringFreeze

The host-side coordinator marked the run as freezing while this stats request was in flight (or about to start); scx_stats responses are undefined while the scheduler’s userspace thread is paused.

Cancelled

The run-wide cancel flag was set (watchdog fired or the run is shutting down) while this stats request was in flight or about to start.

SchedulerError

The scheduler returned a non-zero errno in the typed crate::vmm::StatsResponse envelope. The args payload is preserved so operators can render the scheduler-side message.

Fields

errno: i32

args: Value

MissingResp

The typed envelope was decoded but the inner args map did not contain the expected "resp" key — protocol mismatch with the scheduler.

Fields

args: Value

RequestTooLarge

The caller passed a stats request larger than the client’s crate::vmm::sched_stats::MAX_REQUEST_BYTES cap.

Fields

size: usize

max: usize

ResponseTooLarge

The scheduler’s response grew past crate::vmm::sched_stats::MAX_RESPONSE_BYTES without ever emitting a newline.

Fields

size: usize

max: usize

MutexPoisoned

The shared response mutex was poisoned by a previous panic; the stats client cannot recover for this sample.

Trait Implementations

impl Clone for MissingStatsReason

fn clone(&self) -> MissingStatsReason

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MissingStatsReason

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for MissingStatsReason

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for MissingStatsReason

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

Formats the value using the given formatter.

impl From<&Error> for MissingStatsReason

fn from(e: &Error) -> Self

Downcast the anyhow chain to a typed crate::vmm::SchedStatsError when one is present (every SchedStatsClient failure path boxes a typed variant via anyhow::anyhow!(SchedStatsError::…), so the downcast succeeds on every well-formed sched_stats error). Falls back to MissingStatsReason::NoScheduler carrying the rendered display when the downcast fails — that covers serde / IO / other errors that didn’t originate inside crate::vmm::SchedStatsClient but still surface through the same Result<_, anyhow::Error> return.

impl Hash for MissingStatsReason

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

Feeds this value into the given Hasher.

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

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for MissingStatsReason

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for MissingStatsReason

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Eq for MissingStatsReason

impl StructuralPartialEq for MissingStatsReason