LithosAnanke/kernel/tests/test_stadium_words.c

/* SPDX-License-Identifier: LicenseRef-Starship-1.0
 * Copyright (c) 2023-2026 Robert A. James
 */
/* test_stadium_words.c -- stadium_words_charge on the host (#189, plan 2026-11-13-engine-step4-phase2,
 * Task 4): a v4 node's words charged to the Stadium once a heartbeat tick (Captain Bob, 2026-11-13: "Per
 * heartbeat tick"). N calls of a word are N of stadium_word_dispatch's dispatches -- the same quantum,
 * the same floor left in the reservoir, the same cooling by the ticks since -- and when the words
 * called want more than there is, what there is is shared by their calls, not taken by whichever is
 * charged first. Conservation holds throughout.
 */
#include "harness.h"
#include "starkernel/vm/stadium.h"
#include "starkernel/vm/stadium_words.h"
#include "starkernel/session.h"
#include "starkernel/vm_uuid.h"
#include "starkernel/kmalloc.h"
#include "starkernel/q48_16.h"
#include "starforth_config.h"
#include <stdarg.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>

void *kmalloc(size_t size) { return calloc(1, size); }
void kfree(void *ptr) { free(ptr); }
kmalloc_stats_t kmalloc_get_stats(void)
{
    kmalloc_stats_t s;
    memset(&s, 0, sizeof s);
    s.free_bytes = 512u * 1024u * 1024u;
    return s;
}
void log_message(int level, const char *fmt, ...) { (void)level; (void)fmt; }
void sk_hal_panic(const char *message) { printf("PANIC: %s\n", message); exit(2); }
int blk_flush(uint32_t block_num) { (void)block_num; return 0; }

int main(void)
{
    VMUuid a = stadium_node_key(10);
    uint64_t q = (uint64_t)STADIUM_WORD_HEAT_QUANTUM, r0, pullable;
    uint32_t ids[3];
    uint64_t calls[3];

    CHECK(stadium_boot_init_for(a) == 0 && session_boot_init() == 0 && stadium_birth_node(a, "Hera") == 0,
          "a Stadium with the node born in it");
    stadium_words_init();

    /* the same as that many dispatches: word 7 charged five calls, word 8 dispatched five times */
    ids[0] = 7; calls[0] = 5;
    r0 = stadium_reservoir_peek(a);
    stadium_words_charge(a, ids, calls, 1, 2);
    CHECK(stadium_reservoir_peek(a) == r0 - 5u * q && stadium_words_resident_heat(a) == 5u * q,
          "five calls of word 7 pull five quanta, and it holds them: %llu", (unsigned long long)(r0 - stadium_reservoir_peek(a)));
    {
        unsigned k;
        r0 = stadium_reservoir_peek(a);
        for (k = 0; k < 5; k++) stadium_word_dispatch(a, 8, 2);
        CHECK(stadium_reservoir_peek(a) == r0 - 5u * q && stadium_words_resident_heat(a) == 10u * q,
              "the same as five dispatches of a word");
    }
    CHECK(stadium_conserved(a), "conservation holds");
    /* a resident word cools by the ticks since, once, then takes its calls: as its dispatches would */
    {
        uint64_t before = stadium_words_resident_heat(a);
        ids[0] = 7; calls[0] = 2;
        stadium_words_charge(a, ids, calls, 1, 12);
        ids[0] = 8; calls[0] = 1;
        stadium_word_dispatch(a, 8, 12); stadium_word_dispatch(a, 8, 12);
        CHECK(stadium_words_resident_heat(a) < before + 4u * q, "ten ticks on, both cooled before they took their calls");
        CHECK(stadium_conserved(a), "conservation holds");
    }

    /* no calls, nothing */
    ids[0] = 9; calls[0] = 0;
    r0 = stadium_reservoir_peek(a);
    stadium_words_charge(a, ids, calls, 1, 3);
    CHECK(stadium_reservoir_peek(a) == r0, "a word with no calls is not charged");

    /* more wanted than there is: shared by calls, the floor left */
    pullable = stadium_reservoir_peek(a) - Q48_ONE / 3;
    ids[0] = 20; calls[0] = 3 * (pullable / q);
    ids[1] = 21; calls[1] = 1 * (pullable / q);
    stadium_words_charge(a, ids, calls, 2, 4);
    CHECK(stadium_reservoir_peek(a) >= Q48_ONE / 3 && stadium_reservoir_peek(a) - Q48_ONE / 3 < 4u,
          "the reservoir is left at its third");
    CHECK(stadium_conserved(a), "conservation holds when the calls want more than there is");


    return DONE();
}