hakmem/core/box/hak_core_init.inc.h

// hak_core_init.inc.h — Box: init/shutdown
#ifndef HAK_CORE_INIT_INC_H
#define HAK_CORE_INIT_INC_H

#include <signal.h>
#ifdef __GLIBC__
#include <execinfo.h>
#endif
#include "hakmem_phase7_config.h"  // Phase 7 Task 3

// Debug-only SIGSEGV handler (gated by HAKMEM_DEBUG_SEGV)
static void hakmem_sigsegv_handler(int sig) {
#ifdef __GLIBC__
    void* bt[64]; int n = backtrace(bt, 64);
    fprintf(stderr, "\n[HAKMEM][SIGSEGV] dumping backtrace (%d frames)\n", n);
    backtrace_symbols_fd(bt, n, fileno(stderr));
#else
    (void)sig;
    fprintf(stderr, "\n[HAKMEM][SIGSEGV] (execinfo unavailable)\n");
#endif
}

// Phase 7 Task 3: Pre-warm TLS cache helper
// Pre-allocate blocks to reduce first-allocation miss penalty
// Note: This function is defined later in hakmem.c after sll_refill_small_from_ss is available
// (moved out of header to avoid linkage issues)

static void hak_init_impl(void);
static pthread_once_t g_init_once = PTHREAD_ONCE_INIT;

void hak_init(void) {
    (void)pthread_once(&g_init_once, hak_init_impl);
}

static void hak_init_impl(void) {
    g_initializing = 1;

    // Phase 6.X P0 FIX (2025-10-24): Initialize Box 3 (Syscall Layer) FIRST!
    // This MUST be called before ANY allocation (Tiny/Mid/Large/Learner)
    // dlsym() initializes function pointers to real libc (bypasses LD_PRELOAD)
    hkm_syscall_init();

    // Optional: one-shot SIGSEGV backtrace for early crash diagnosis
    do {
        const char* dbg = getenv("HAKMEM_DEBUG_SEGV");
        if (dbg && atoi(dbg) != 0) {
            struct sigaction sa; memset(&sa, 0, sizeof(sa));
            sa.sa_flags = SA_RESETHAND;
            sa.sa_handler = hakmem_sigsegv_handler;
            sigaction(SIGSEGV, &sa, NULL);
        }
    } while (0);

    // NEW Phase 6.11.1: Initialize debug timing
    hkm_timing_init();

    // NEW Phase 6.11.1: Initialize whale fast-path cache
    hkm_whale_init();

    // NEW Phase Hybrid: Initialize Mid Range MT allocator (8-32KB, mimalloc-style)
    mid_mt_init();

    // NEW Phase 6.8: Initialize configuration system (replaces init_free_policy + init_thp_policy)
    hak_config_init();

    // Phase 6.16: Initialize FrozenPolicy (SACS-3)
    hkm_policy_init();

    // Phase 6.15 P0.3: Configure EVO sampling from environment variable
    // HAKMEM_EVO_SAMPLE: 0=disabled (default), N=sample every 2^N calls
    // Example: HAKMEM_EVO_SAMPLE=10 → sample every 1024 calls
    //          HAKMEM_EVO_SAMPLE=16 → sample every 65536 calls
    char* evo_sample_str = getenv("HAKMEM_EVO_SAMPLE");
    if (evo_sample_str && atoi(evo_sample_str) > 0) {
        int freq = atoi(evo_sample_str);
        if (freq >= 64) {
            fprintf(stderr, "[hakmem] Warning: HAKMEM_EVO_SAMPLE=%d too large, using 63\n", freq);
            freq = 63;
        }
        g_evo_sample_mask = (1ULL << freq) - 1;
        HAKMEM_LOG("EVO sampling enabled: every 2^%d = %llu calls\n",
                   freq, (unsigned long long)(g_evo_sample_mask + 1));
    } else {
        g_evo_sample_mask = 0;  // Disabled by default
        HAKMEM_LOG("EVO sampling disabled (HAKMEM_EVO_SAMPLE not set or 0)\n");
    }

#ifdef __linux__
    // Record baseline KPIs
    memset(g_latency_histogram, 0, sizeof(g_latency_histogram));
    g_latency_samples = 0;

    get_page_faults(&g_baseline_soft_pf, &g_baseline_hard_pf);
    g_baseline_rss_kb = get_rss_kb();

    HAKMEM_LOG("Baseline: soft_pf=%lu, hard_pf=%lu, rss=%lu KB\n",
           (unsigned long)g_baseline_soft_pf,
           (unsigned long)g_baseline_hard_pf,
           (unsigned long)g_baseline_rss_kb);
#endif

    HAKMEM_LOG("Initialized (PoC version)\n");
    HAKMEM_LOG("Sampling rate: 1/%d\n", SAMPLING_RATE);
    HAKMEM_LOG("Max sites: %d\n", MAX_SITES);

    // Bench preset: Tiny-only (disable non-essential subsystems)
    {
        char* bt = getenv("HAKMEM_BENCH_TINY_ONLY");
        if (bt && atoi(bt) != 0) {
            g_bench_tiny_only = 1;
        }
    }

    // Under LD_PRELOAD, enforce safer defaults for Tiny path unless overridden
    {
        char* ldpre = getenv("LD_PRELOAD");
        if (ldpre && strstr(ldpre, "libhakmem.so")) {
            g_ldpreload_mode = 1;
            // Default LD-safe mode if not set: 1 (Tiny-only)
            char* lds = getenv("HAKMEM_LD_SAFE");
            if (lds) { /* NOP used in wrappers */ } else { setenv("HAKMEM_LD_SAFE", "1", 0); }
            if (!getenv("HAKMEM_TINY_TLS_SLL")) {
                setenv("HAKMEM_TINY_TLS_SLL", "0", 0);  // disable TLS SLL by default
            }
            if (!getenv("HAKMEM_TINY_USE_SUPERSLAB")) {
                setenv("HAKMEM_TINY_USE_SUPERSLAB", "0", 0);  // disable SuperSlab path by default
            }
        }
    }

    // Runtime safety toggle
    char* safe_free_env = getenv("HAKMEM_SAFE_FREE");
    if (safe_free_env && atoi(safe_free_env) != 0) {
        g_strict_free = 1;
        HAKMEM_LOG("Strict free safety enabled (HAKMEM_SAFE_FREE=1)\n");
    } else {
        // Heuristic: if loaded via LD_PRELOAD, enable strict free by default
        char* ldpre = getenv("LD_PRELOAD");
        if (ldpre && strstr(ldpre, "libhakmem.so")) {
            g_ldpreload_mode = 1;
            g_strict_free = 1;
            HAKMEM_LOG("Strict free safety auto-enabled under LD_PRELOAD\n");
        }
    }

    // Invalid free logging toggle (default off to avoid spam under LD_PRELOAD)
    char* invlog = getenv("HAKMEM_INVALID_FREE_LOG");
    if (invlog && atoi(invlog) != 0) {
        g_invalid_free_log = 1;
        HAKMEM_LOG("Invalid free logging enabled (HAKMEM_INVALID_FREE_LOG=1)\n");
    }

    // Phase 7.4: Cache HAKMEM_INVALID_FREE to eliminate 44% CPU overhead
    // Perf showed getenv() on hot path consumed 43.96% CPU time (26.41% strcmp + 17.55% getenv)
    char* inv = getenv("HAKMEM_INVALID_FREE");
    if (inv && strcmp(inv, "fallback") == 0) {
        g_invalid_free_mode = 0;  // fallback mode: route invalid frees to libc
        HAKMEM_LOG("Invalid free mode: fallback to libc (HAKMEM_INVALID_FREE=fallback)\n");
    } else {
        // Under LD_PRELOAD, prefer safety: default to fallback unless explicitly overridden
        char* ldpre = getenv("LD_PRELOAD");
        if (ldpre && strstr(ldpre, "libhakmem.so")) {
            g_ldpreload_mode = 1;
            g_invalid_free_mode = 0;
            HAKMEM_LOG("Invalid free mode: fallback to libc (auto under LD_PRELOAD)\n");
        } else {
            g_invalid_free_mode = 1;  // default: skip invalid-free check
            HAKMEM_LOG("Invalid free mode: skip check (default)\n");
        }
    }

    // NEW Phase 6.8: Feature-gated initialization (check g_hakem_config flags)
    if (HAK_ENABLED_ALLOC(HAKMEM_FEATURE_POOL)) {
        hak_pool_init();
    }

    // NEW Phase 6.13: L2.5 LargePool (64KB-1MB allocations)
    hak_l25_pool_init();

    if (!g_bench_tiny_only && HAK_ENABLED_CACHE(HAKMEM_FEATURE_BIGCACHE)) {
        hak_bigcache_init();
        hak_bigcache_set_free_callback(bigcache_free_callback);
    }

    if (!g_bench_tiny_only && HAK_ENABLED_LEARNING(HAKMEM_FEATURE_ELO)) {
        hak_elo_init();
        // Phase 6.11.4 P0-2: Initialize cached strategy to default (strategy 0)
        atomic_store(&g_cached_strategy_id, 0);
    }

    if (!g_bench_tiny_only && HAK_ENABLED_MEMORY(HAKMEM_FEATURE_BATCH_MADVISE)) {
        hak_batch_init();
    }

    if (!g_bench_tiny_only && HAK_ENABLED_LEARNING(HAKMEM_FEATURE_EVOLUTION)) {
        hak_evo_init();
    }

    if (!g_bench_tiny_only) {
        // Phase 6.16: Initialize ACE stats (sampling) – default off
        hkm_ace_stats_init();
        // Phase 6.16: Initialize sampling profiler – default off
        hkm_prof_init();
        // Size histogram sampling (optional)
        hkm_size_hist_init();
    }

    if (!g_bench_tiny_only) {
        // Start CAP learner (optional, env-gated)
        hkm_learner_init();
    }

    // NEW Phase 6.10: Site Rules (MVP: always ON)
    // MT note: default disabled unless HAKMEM_SITE_RULES=1
    char* sr_env = getenv("HAKMEM_SITE_RULES");
    g_site_rules_enabled = (sr_env && atoi(sr_env) != 0);
    if (!g_bench_tiny_only && g_site_rules_enabled) {
        hak_site_rules_init();
    }

    // NEW Phase 6.12: Tiny Pool (≤1KB allocations)
    hak_tiny_init();

    // Env: optional Tiny flush on exit (memory efficiency evaluation)
    {
        char* tf = getenv("HAKMEM_TINY_FLUSH_ON_EXIT");
        if (tf && atoi(tf) != 0) {
            g_flush_tiny_on_exit = 1;
        }
        char* ud = getenv("HAKMEM_TINY_ULTRA_DEBUG");
        if (ud && atoi(ud) != 0) {
            g_ultra_debug_on_exit = 1;
        }
        // Register exit hook if any of the debug/flush toggles are on
        // or when path debug is requested.
        if (g_flush_tiny_on_exit || g_ultra_debug_on_exit || getenv("HAKMEM_TINY_PATH_DEBUG")) {
            atexit(hak_flush_tiny_exit);
        }
    }

    // NEW Phase ACE: Initialize Adaptive Control Engine
    hkm_ace_controller_init(&g_ace_controller);
    if (g_ace_controller.enabled) {
        hkm_ace_controller_start(&g_ace_controller);
        HAKMEM_LOG("ACE Learning Layer enabled and started\n");
    }

    // Phase 7 Task 3: Pre-warm TLS cache (reduce first-allocation miss penalty)
#if HAKMEM_TINY_PREWARM_TLS
    // Forward declaration from hakmem_tiny.c
    extern void hak_tiny_prewarm_tls_cache(void);
    hak_tiny_prewarm_tls_cache();
    HAKMEM_LOG("TLS cache pre-warmed for %d classes\n", TINY_NUM_CLASSES);
#endif

    g_initializing = 0;
    // Publish that initialization is complete
    atomic_thread_fence(memory_order_seq_cst);
    g_initialized = 1;
}

void hak_shutdown(void) {
    if (!g_initialized) return;

    // NEW Phase ACE: Shutdown Adaptive Control Engine FIRST (before other subsystems)
    hkm_ace_controller_destroy(&g_ace_controller);

    if (!g_bench_tiny_only) {
        printf("[hakmem] Shutting down...\n");
        hak_print_stats();
    }

    // NEW Phase 6.9: Shutdown L2 Pool
    if (!g_bench_tiny_only) hak_pool_shutdown();

    // NEW Phase 6.13: Shutdown L2.5 LargePool
    if (!g_bench_tiny_only) hak_l25_pool_shutdown();

    // NEW: Shutdown BigCache Box
    if (!g_bench_tiny_only) hak_bigcache_shutdown();

    // NEW Phase 6.2: Shutdown ELO Strategy Selection
    if (!g_bench_tiny_only) hak_elo_shutdown();

    // NEW Phase 6.3: Shutdown madvise Batching
    if (!g_bench_tiny_only) hak_batch_shutdown();

    // NEW Phase 6.10: Shutdown Site Rules
    if (!g_bench_tiny_only) hak_site_rules_shutdown();

    // NEW Phase 6.12: Print Tiny Pool statistics
    if (!g_bench_tiny_only) hak_tiny_print_stats();

    // NEW Phase 6.11.1: Print whale cache statistics
    if (!g_bench_tiny_only) {
        hkm_whale_dump_stats();
        // NEW Phase 6.11.1: Shutdown whale cache
        hkm_whale_shutdown();
    }

    // NEW Phase 6.11.1: Shutdown debug timing (must be last!)
    if (!g_bench_tiny_only) hkm_timing_shutdown();

    // Phase 6.16: Dump sampling profiler
    if (!g_bench_tiny_only) hkm_prof_shutdown();

    // Stop learner thread
    if (!g_bench_tiny_only) hkm_learner_shutdown();

    // Stop Tiny background components (e.g., Intelligence Engine)
    hak_tiny_shutdown();

    g_initialized = 0;
}



#endif // HAK_CORE_INIT_INC_H