hakmem/core/hakmem_ace.c

#include "hakmem_ace.h"
#include "hakmem_pool.h"
#include "hakmem_l25_pool.h"
#include "hakmem_ace_stats.h"
#include "hakmem_policy.h"
#include "hakmem_debug.h"

// Map size to MidPool/LargePool and allocate.
// Phase 6.21: Bridge classes (40KB, 52KB) now hardcoded, DYN1/DYN2 disabled
static inline size_t round_to_mid_class(size_t s, double wmax, const FrozenPolicy* pol) {
    // Build candidate set: 2/4/8/16/32/40/52 KiB (Bridge classes now fixed)
    size_t cand[7] = {
        POOL_CLASS_2KB, POOL_CLASS_4KB, POOL_CLASS_8KB, POOL_CLASS_16KB, POOL_CLASS_32KB,
        POOL_CLASS_40KB, POOL_CLASS_52KB  // Phase 6.21: Bridge classes
    };
    // Legacy: DYN1/DYN2 support (currently disabled in Phase 6.21)
    // Note: If DYN classes are re-enabled, they should override Bridge classes
    if (pol) {
        if (pol->mid_dyn1_bytes >= POOL_MIN_SIZE && pol->mid_dyn1_bytes <= POOL_MAX_SIZE) cand[5] = (size_t)pol->mid_dyn1_bytes;
        if (pol->mid_dyn2_bytes >= POOL_MIN_SIZE && pol->mid_dyn2_bytes <= POOL_MAX_SIZE) cand[6] = (size_t)pol->mid_dyn2_bytes;
    }
    // Choose the smallest c >= s that also satisfies c ≤ wmax*s
    size_t best = 0; // 0 = not found
    for (int i = 0; i < 7; i++) {
        size_t c = cand[i];
        if (c == 0) continue;
        if (c < s) continue;
        if ((double)c > wmax * (double)s) continue;
        if (best == 0 || c < best) best = c;
    }
    return best;
}

static inline size_t round_to_large_class(size_t s, double wmax) {
    const size_t classes[L25_NUM_CLASSES] = {
        L25_CLASS_64KB, L25_CLASS_128KB, L25_CLASS_256KB, L25_CLASS_512KB, L25_CLASS_1MB
    };
    for (int i = 0; i < L25_NUM_CLASSES; i++) {
        size_t c = classes[i];
        if (s <= c) {
            if ((double)c <= wmax * (double)s) return c;
            return 0; // not allowed → fallback
        }
    }
    return 0; // above 1MB
}

void* hkm_ace_alloc(size_t size, uintptr_t site_id, const FrozenPolicy* pol) {
    double wmax_mid = (pol ? pol->w_max_mid : 1.33);
    double wmax_large = (pol ? pol->w_max_large : 1.25);

    // MidPool: 2–52KiB (Phase 6.21: with Bridge classes for W_MAX rounding)
    if (size <= POOL_MAX_SIZE) {
        size_t r = round_to_mid_class(size, wmax_mid, pol);
        if (r != 0) {
            HKM_TIME_START(t_mid_get);
            void* p = hak_pool_try_alloc(r, site_id);
            HKM_TIME_END(HKM_CAT_POOL_GET, t_mid_get);
            hkm_ace_stat_mid_attempt(p != NULL);
            if (p) return p;
        }
        // If rounding not allowed or miss, fallthrough to large class rounding below
    }

    // LargePool: 64KiB–1MiB (with W_MAX rounding)
    if (size <= L25_MAX_SIZE) {
        size_t r = round_to_large_class(size, wmax_large);
        if (r != 0) {
            HKM_TIME_START(t_l25_get);
            void* p = hak_l25_pool_try_alloc(r, site_id);
            HKM_TIME_END(HKM_CAT_L25_GET, t_l25_get);
            hkm_ace_stat_large_attempt(p != NULL);
            if (p) return p;
        }
    } else if (size > POOL_MAX_SIZE && size < L25_MIN_SIZE) {
        // Gap 32–64KiB: try rounding up to 64KiB if permitted
        size_t r = round_to_large_class(L25_MIN_SIZE, wmax_large); // check 64KiB vs size
        if ((double)L25_MIN_SIZE <= wmax_large * (double)size) {
            HKM_TIME_START(t_l25_get2);
            void* p = hak_l25_pool_try_alloc(L25_MIN_SIZE, site_id);
            HKM_TIME_END(HKM_CAT_L25_GET, t_l25_get2);
            hkm_ace_stat_large_attempt(p != NULL);
            if (p) return p;
        }
    }

    hkm_ace_stat_l1_fallback();
    return NULL;  // Miss: let caller fallback to malloc
}