hakmem/core/box/front_gate_box.h

// front_gate_box.h - Front Gate Box (SFC/SLL priority and helpers)
#pragma once
#include <stddef.h>
#include "hakmem_tiny.h"

// Try to pop a block from Front Gate (SFC -> TLS SLL).
// Returns 1 on success and stores the pointer to *out_ptr, else 0.
int front_gate_try_pop(int class_idx, void** out_ptr);

// After backend refill, optionally cascade some blocks SLL -> SFC.
// Intended to keep SFC warm without extra backend calls.
void front_gate_after_refill(int class_idx, int refilled_count);

// Push a block to TLS freelist (SLL). Used by free fast path.
void front_gate_push_tls(int class_idx, hak_base_ptr_t ptr);