LithosAnanake/include/starkernel/vm/stadium_words.h

/*
  StarForth — Steady-State Virtual Machine Runtime

  Copyright (c) 2023–2025 Robert A. James
  All rights reserved.

  This file is part of the StarForth project.

  Licensed under the StarForth License, Version 1.0 (the "License");
  you may not use this file except in compliance with the License.

  You may obtain a copy of the License at:
      https://github.com/star.4th@proton.me/StarForth/LICENSE.txt

  This software is provided "AS IS", WITHOUT WARRANTY OF ANY KIND,
  express or implied, including but not limited to the warranties of
  merchantability, fitness for a particular purpose, and noninfringement.

 See the License for the specific language governing permissions and
 limitations under the License.

 */

/**
 * stadium_words.h - Word patrons on the Stadium (FABRIC-0.md §17.3/§17.7,
 * punch list item 4.1)
 *
 * The word-specific layer on top of the generic L0 engine (stadium.h).
 * Nothing in stadium.c/.h knows a word patron exists -- it only ever sees
 * cell_index, VMUuid, and StadiumPatronHeader. This file is where "word"
 * becomes a concrete meaning: a word_id -> cell_index map (kernel-side,
 * deliberately NOT a DictEntry field, decided 2026-08-05), the starter-grant
 * admission rule (Option B), and the reservoir-quantum touch/cool that feed
 * and drain a resident word's Stadium heat.
 *
 * `execution_heat` and `dict_hash` are untouched by anything in this file
 * (§17.7) -- this is a second, independent conserved quantity living in the
 * Stadium cell's `heat` field, not a representation of the first.
 */

#ifndef STARKERNEL_VM_STADIUM_WORDS_H
#define STARKERNEL_VM_STADIUM_WORDS_H

#ifdef __STARKERNEL__

#include <stdint.h>
#include "starkernel/vm_uuid.h"

/*
 * stadium_words_init - Allocates and zeroes the word_id -> cell_index map
 * (DICTIONARY_SIZE entries per VM quota slot, stadium_max_vm_count() slots,
 * kmalloc'd -- was a flat static array before 2026-08-15, when the VM count
 * bound became RAM-derived rather than a compile-time constant). Must be
 * called after stadium_boot_init() and stadium_birth_hera(), before any word
 * ever dispatches. NOT safe to call twice -- unlike the old zero-only
 * version, a second call would kmalloc a second set of tables and leak the
 * first; guarded internally as a no-op if already initialized. Nothing
 * calls it twice today.
 *
 * item 4.2 (FABRIC-0.md §25.5): the map is keyed by quota slot, not just
 * word_id -- word_id is assigned per-VM (vm->next_word_id), not globally
 * unique, so a single shared word_id -> cell_index map aliased different
 * VMs' words onto each other's Stadium cells and reservoirs the moment a
 * second VM (Hermes) held a quota. One system-wide init call still covers
 * every slot; no per-VM init call is needed.
 */
void stadium_words_init(void);

/*
 * stadium_word_dispatch - The per-dispatch entry point (FABRIC-0.md §17.7),
 * called once per DictEntry touched at each of vm_core.c's three
 * physics_execution_heat_increment() call sites -- deliberately mirroring
 * that function's existing call pattern 1:1, including the entry != canon
 * double-touch case, rather than inventing a different shape.
 *
 * If word_id is already resident: applies the redirected Loop #3 cooling
 * (fraction of the cell's own current heat, scaled by elapsed_ticks since
 * this word's own last touch -- STADIUM_WORD_COOL_RATE_Q48) crediting the
 * cooled amount back to vm_id's reservoir, then pulls
 * STADIUM_WORD_HEAT_QUANTUM from the reservoir into the cell -- clamped to
 * what the reservoir actually holds AND to a floor of Q48_ONE / 3 that
 * word-execution admission alone may never dip the reservoir below
 * (FABRIC-0.md §25.7, Captain Bob's ruling 2026-08-06: this pull fires on
 * EVERY dispatch, not just first admission, and without a floor exhausts a
 * VM's entire reservoir in ~32 dispatches, starving any application-level
 * economy -- e.g. item 4.2's Hermes -- sharing the same VM's reservoir).
 * Application-level pulls (stadium_reservoir_pull() called directly) are
 * not subject to this floor.
 *
 * If word_id is not resident (or the map's entry is stale -- self-healing
 * check against the cell's discriminator bit and identity, covers both a
 * prior eviction and a FORGET/redefine word_id reuse this function did not
 * itself clear): attempts Option B starter-grant admission -- pulls
 * STADIUM_WORD_HEAT_QUANTUM from the reservoir (same floor as above),
 * builds an unpinned COOL candidate, calls stadium_admit(). On refusal,
 * pushes the pulled quantum back (rollback, preserves conservation across
 * the failed attempt). On success, records the mapping and increments the
 * promotion counter.
 *
 * No-op if word_id == WORD_ID_INVALID, word_id >= DICTIONARY_SIZE, or vm_id
 * holds no Stadium quota.
 *
 * @param vm_id           Owning VM -- vm->stadium_vm_id at every call site.
 *                        Scopes the word_id -> cell_index lookup to this
 *                        VM's own quota slot (item 4.2, FABRIC-0.md §25.5) so
 *                        two VMs' independently-numbered word_ids cannot
 *                        alias onto each other's cells/reservoirs.
 * @param word_id         The dispatching DictEntry's stable word_id.
 * @param heartbeat_ticks Current vm->heartbeat.tick_count (virtual tick,
 *                        never wall-clock -- same convention as every other
 *                        decay computation in this tree).
 */
void stadium_word_dispatch(VMUuid vm_id, uint32_t word_id, uint64_t heartbeat_ticks);

/*
 * stadium_word_forget - Coherence hook for FORGET (word_id recycling).
 * vm_dictionary_untrack_entry() must call this BEFORE the word_id is pushed
 * onto vm->recycled_word_ids -- otherwise the next word assigned the same
 * recycled id would alias onto the forgotten word's still-resident cell and
 * its stale heat (same failure class as the 2026-08-02 block_words.c
 * aliasing bug). Evicts the cell if word_id is resident (crediting its heat
 * back to the reservoir via stadium_evict()'s own credit path) and clears
 * the map entry. No-op if word_id is not resident, out of range, or vm_id
 * holds no Stadium quota.
 *
 * @param vm_id    Owning VM -- vm->stadium_vm_id (item 4.2, FABRIC-0.md §25.5:
 *                 scopes the lookup to this VM's own word_slots, same
 *                 reason stadium_word_dispatch() takes it).
 * @param word_id  The DictEntry's word_id, about to be recycled.
 */
void stadium_word_forget(VMUuid vm_id, uint32_t word_id);

/*
 * stadium_words_resident_heat - Sum of heat held by vm_id's own
 * word-execution residents only (item 4.1's cells, tracked in this file's
 * own word_slots map) -- NOT messages/channels/other application residents,
 * which stadium_resident_sum() (stadium.h, item 4.2) mixes in alongside
 * everything else a VM owns. Exists so a VM's own application-level
 * conservation check (e.g. Hermes's HERMES-K, FABRIC-0.md §25.7, Captain
 * Bob's ruling 2026-08-06) can add this as an explicit term instead of
 * silently omitting word-execution heat it has no other way to see.
 *
 * Walks all DICTIONARY_SIZE word_slots for vm_id's quota slot; each
 * resident entry contributes its cell's current heat, verified live against
 * the discriminator bitmap (same self-healing pattern as
 * resolve_resident_cell() -- a stale map entry contributes 0, not garbage).
 *
 * @param vm_id  The VM whose word-execution residents to sum.
 */
uint64_t stadium_words_resident_heat(VMUuid vm_id);

/*
 * stadium_words_stats - Promotion/eviction counters (same shape as the old
 * cache's HotwordsStats.promotions/.evictions, not that struct -- §25.5's
 * acceptance for item 4.1). Promotion = a successful starter-grant
 * admission. Eviction = this word's cell was reaped by another admission's
 * eviction fallback (stadium_admit()'s density comparison), detected
 * lazily via the self-healing stale check in stadium_word_dispatch(), or
 * explicitly via stadium_word_forget(). Scoped to vm_id's own quota slot
 * (item 4.2) -- counters are no longer system-wide.
 */
void stadium_words_stats(VMUuid vm_id, uint64_t *promotions, uint64_t *evictions);

/*
 * stadium_words_print_boot_diagnostics - Console output satisfying item
 * 4.1's "observable via a diagnostic word or boot console output"
 * acceptance line. Prints promotions/evictions, then
 * Σ(resident heat) + reservoir against Q48_ONE as a conservation check --
 * not required by the acceptance text, but the mechanism proves nothing if
 * this silently doesn't hold. The heat sum is scoped to vm_id's own quota
 * (stadium_resident_sum(), item 4.2, FABRIC-0.md §25.5) so two VMs' checks
 * close independently instead of mixing both VMs' resident heat together.
 *
 * @param vm_id  The VM whose reservoir to read (vm_uuid_hera() today).
 */
void stadium_words_print_boot_diagnostics(VMUuid vm_id);

#endif /* __STARKERNEL__ */

#endif /* STARKERNEL_VM_STADIUM_WORDS_H */