hakmem/core/tiny_route.h

// tiny_route.h - Route Fingerprint (Box-boundary tracing, ultra-light)
#pragma once

#include <stdint.h>
#include <stdlib.h>
#include <stdatomic.h>
#include "tiny_debug_ring.h"

// Bits (keep <= 63 to stay in one 64-bit word)
//  0: refill_enter
//  1/2: ready_try/ready_hit
//  3/4: mail_try/mail_hit
//  5/6: sticky_try/sticky_hit
//  7/8: hot_try/hot_hit
//  9/10: bench_try/bench_hit
// 11/12: reg_try/reg_hit
// 13/14: adopt_try/adopt_hit
// 15: mmap_path
// 16: free_enter
// 17: free_same_thread
// 18: free_remote_transition
// 19: first_free_transition
// 20: mailbox_publish

static __thread uint64_t g_route_fp __attribute__((unused));
static __thread uint32_t g_route_seq __attribute__((unused));
static __thread int g_route_active __attribute__((unused));
static int g_route_enable_env = -1;
static int g_route_sample_lg = -1;

static inline int route_enabled_runtime(void) {
    if (__builtin_expect(g_route_enable_env == -1, 0)) {
        const char* e = getenv("HAKMEM_ROUTE");
        g_route_enable_env = (e && *e && *e != '0') ? 1 : 0;
    }
    return g_route_enable_env;
}

static inline uint32_t route_sample_mask(void) {
    if (__builtin_expect(g_route_sample_lg == -1, 0)) {
        const char* e = getenv("HAKMEM_ROUTE_SAMPLE_LG");
        int lg = (e && *e) ? atoi(e) : 10; // 1/1024 既定
        if (lg < 0) lg = 0;
        if (lg > 24) lg = 24;
        g_route_sample_lg = lg;
    }
    return (g_route_sample_lg >= 31) ? 0xFFFFFFFFu : ((1u << g_route_sample_lg) - 1u);
}

#if HAKMEM_BUILD_RELEASE && !HAKMEM_ROUTE
  #define ROUTE_BEGIN(cls) do { (void)(cls); } while(0)
  #define ROUTE_MARK(bit)  do { (void)(bit); } while(0)
  #define ROUTE_COMMIT(cls, tag) do { (void)(cls); (void)(tag); } while(0)
  static inline void route_free_commit(int class_idx, uint64_t bits, uint16_t tag) {
      (void)class_idx; (void)bits; (void)tag;
  }
#else
  #define ROUTE_BEGIN(cls) do { \
      if (__builtin_expect(!route_enabled_runtime(), 1)) { g_route_active = 0; break; } \
      uint32_t m = route_sample_mask(); \
      uint32_t s = ++g_route_seq; \
      g_route_active = ((s & m) == 0u); \
      g_route_fp = 0ull; \
      (void)(cls); \
  } while(0)

  #define ROUTE_MARK(bit) do { if (__builtin_expect(g_route_active, 0)) { g_route_fp |= (1ull << (bit)); } } while(0)

  #define ROUTE_COMMIT(cls, tag) do { \
      if (__builtin_expect(g_route_active, 0)) { \
          uintptr_t aux = ((uintptr_t)(tag & 0xFFFF) << 48) | (uintptr_t)(g_route_fp & 0x0000FFFFFFFFFFFFull); \
          tiny_debug_ring_record(TINY_RING_EVENT_ROUTE, (uint16_t)(cls), (void*)(uintptr_t)g_route_fp, aux); \
          g_route_active = 0; \
      } \
  } while(0)

  static inline void route_free_commit(int class_idx, uint64_t bits, uint16_t tag) {
      if (!route_enabled_runtime()) return;
      uintptr_t aux = ((uintptr_t)(tag & 0xFFFF) << 48) | (uintptr_t)(bits & 0x0000FFFFFFFFFFFFull);
      tiny_debug_ring_record(TINY_RING_EVENT_ROUTE, (uint16_t)class_idx, (void*)(uintptr_t)bits, aux);
  }
#endif

// Note: Build-time gate removed to keep integration simple; runtime env controls activation.