Enum Shed 

pub enum Shed {
    Concurrency {
        limit: usize,
        in_flight: usize,
    },
    LaneFull {
        lane: Lane,
        ceiling: usize,
        limit: usize,
    },
    Reserved {
        occupied: usize,
        limit: usize,
        reserve: usize,
    },
    Memory {
        class: OpClass,
        wanted: u64,
        reserved: u64,
        budget: u64,
    },
}

Why the governor shed an operation.

Variants

Concurrency

Gate 1: the governed concurrency limit is full.

Fields

limit: usize

The limit in force at the moment of the refusal — the governed one, which is not the configured one and moves on its own. Reported rather than assumed, or an operator reads a number in a log that matches nothing in a config file.

in_flight: usize

How many operations were in flight.

LaneFull

Gate 1b: this operation’s lane is full, though the server as a whole is not. The other lanes’ floors are what is holding the slots; see Lane::floor.

Fields

lane: Lane

The lane that was full.

ceiling: usize

What that lane may hold under the governed limit right now.

limit: usize

The governed server-wide limit.

Reserved

Gate 1c: the claim asked for a slot the caller had told this governor to hold back (Governor::claim_reserving), though the server as a whole is not full.

Its own variant rather than Shed::Concurrency with a smaller limit in it, because reporting a reduced limit as the limit is the exact failure the unbounded listener is about: an operator would read limit: 2 out of a log on a box configured for 256 and conclude the gate was broken. Both numbers travel, and the caller that supplied the reserve is the one that gets to name the rule.

Fields

occupied: usize

Operations in flight when the claim failed.

limit: usize

The governed server-wide limit — the real one, unreduced.

reserve: usize

How many slots of it the caller asked to be held back from this claim.

Memory

Gate 2: the memory budget is spoken for.

Fields

class: OpClass

The class whose estimate did not fit.

wanted: u64

What [OpClass::estimated_bytes] asked for.

reserved: u64

What was already reserved.

budget: u64

The budget.

Trait Implementations

impl Clone for Shed

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 Shed

impl Debug for Shed

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

Formats the value using the given formatter.

impl Eq for Shed

impl PartialEq for Shed

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Shed