Struct FeedbackVector 

pub struct FeedbackVector { /* private fields */ }

Runtime feedback vector for a single function activation.

A FeedbackVector is created from a FeedbackMetadata at runtime (once per function object, not once per call). The interpreter reads and writes InlineCacheState entries to record what types it has seen at each instruction site.

Slot transitions

Slots start at InlineCacheState::Uninitialized and can only move forward through the ordering Uninitialized → Monomorphic → Polymorphic → Megamorphic. Use FeedbackVector::transition to advance a slot while respecting this invariant.

Implementations

impl FeedbackVector

pub fn new(metadata: &FeedbackMetadata) -> Self

Create a new FeedbackVector from compile-time metadata.

All slots start at InlineCacheState::Uninitialized.

pub fn slot_count(&self) -> u32

The total number of slots in this vector.

pub fn kind_of(&self, slot: u32) -> Option<FeedbackSlotKind>

Return the FeedbackSlotKind for slot, or None if out of range.

pub fn get_state(&self, slot: u32) -> Option<InlineCacheState>

Return the current InlineCacheState for slot, or None if out of range.

pub fn set_state(&mut self, slot: u32, state: InlineCacheState) -> bool

Unconditionally set the InlineCacheState for slot.

Returns true if the slot existed (state was updated), false otherwise.

pub fn transition(&mut self, slot: u32, new_state: InlineCacheState) -> bool

Advance the slot to new_state only if new_state is strictly higher in the ordering than the current state.

Returns true if the state was advanced, false otherwise (including when the slot index is out of range).

Trait Implementations

impl Clone for FeedbackVector

fn clone(&self) -> FeedbackVector

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FeedbackVector

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

Formats the value using the given formatter.