Struct SsmStatePool 

pub struct SsmStatePool { /* private fields */ }

A free-list pool of SequenceSlots for SSM-based models.

Pre-allocates capacity slots at construction time. Slots are identified by their index into the internal slots vector.

Free slots are tracked by a free_list: Vec<usize>. alloc pops from the list; release resets the slot and pushes back.

Implementations

impl SsmStatePool

pub fn from_forward_pass( forward_pass: &dyn ForwardPass, capacity: usize, max_context_length: usize, ) -> Self

Create a pool by calling ForwardPass::allocate_sequence_state for each slot.

This is the preferred construction path because it delegates state allocation to the architecture implementation, rather than hard-coding the state type at the call site. The runtime calls this once at model load time, after ForwardPass is available.

let pool = SsmStatePool::from_forward_pass(fwd_pass.as_ref(), capacity, max_ctx);

pub fn new<F>(capacity: usize, make_state: F) -> Self

where F: FnMut(usize) -> Box<dyn SequenceState>,

Create a new pool using a factory closure to produce each slot’s state.

The closure is called once per slot with the slot index. Use it to initialise arch-specific state (e.g. Mamba2SequenceState::new(...)).

let pool = SsmStatePool::new(8, |_| {
    Box::new(Mamba2SequenceState::new(24, 16, 256, 4096))
});

pub fn alloc(&mut self, request_id: u64) -> PoolResult<usize>

Allocate a free slot and bind it to request_id.

Returns Ok(slot_idx) on success.

Errors

Returns PoolError::Exhausted when no free slots are available.

pub fn release(&mut self, idx: usize) -> PoolResult<()>

Release slot idx back to the free list.

The slot’s state is reset (zeroed) and its request_id cleared.

Errors

Returns PoolError::InvalidSlot if idx is out of range or already free.

pub fn slot(&self, idx: usize) -> Option<&SequenceSlot>

Get a shared reference to slot idx.

Returns None if the slot has never been initialised (should not happen for a correctly-constructed pool) or the index is out of range.

pub fn slot_mut(&mut self, idx: usize) -> Option<&mut SequenceSlot>

Get a mutable reference to slot idx.

Returns None if the slot is uninitialised or out of range.

pub fn capacity(&self) -> usize

Total pool capacity (never changes).

pub fn free_count(&self) -> usize

Number of currently free (unallocated) slots.

pub fn used_count(&self) -> usize

Number of currently allocated (live) slots.