Priority-2 ENV Cache: hakmem_debug.c (1変数追加、1箇所置換)

【追加ENV変数】
- HAKMEM_TIMING (default: 0)

【置換ファイル】
- core/hakmem_debug.c (1箇所 → ENV Cache)

【変更詳細】
1. ENV Cache (hakmem_env_cache.h):
   - 構造体に1変数追加 (47→48変数)
   - hakmem_env_cache_init()に初期化追加
   - アクセサマクロ追加
   - カウント更新: 47→48

2. hakmem_debug.c:
   - hkm_timing_init():
     getenv("HAKMEM_TIMING") + strcmp() → HAK_ENV_TIMING_ENABLED()
   - #include "hakmem_env_cache.h" 追加

【効果】
- デバッグタイミング初期化からgetenv()呼び出しを排除
- Cold pathだが、起動時のENV参照を削減

【テスト】
✅ make shared → 成功
✅ /tmp/test_mixed3_final → PASSED

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

core/hakmem_debug.c

@@ -4,6 +4,7 @@
 // Date: 2025-10-21
 
 #include "hakmem_debug.h"
+#include "hakmem_env_cache.h"  // Priority-2: ENV cache
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -150,11 +151,8 @@ void hkm_timing_init(void) {
     if (g_initialized) return;
 
 #if !HAKMEM_BUILD_RELEASE
-    // Check HAKMEM_TIMING environment variable (gated behind !HAKMEM_BUILD_RELEASE)
-    const char* env = getenv("HAKMEM_TIMING");
-    if (env && strcmp(env, "1") == 0) {
-        g_timing_enabled = 1;
-    }
+    // Priority-2: Use cached ENV (gated behind !HAKMEM_BUILD_RELEASE)
+    g_timing_enabled = HAK_ENV_TIMING_ENABLED();
 #else
     g_timing_enabled = 0;  // Always disabled in release builds
 #endif

core/hakmem_env_cache.h

@@ -84,6 +84,9 @@ typedef struct {
     // ===== Warm Path: SmallMid (1 variable) =====
     int smallmid_enable;             // HAKMEM_SMALLMID_ENABLE (default: 0)
 
+    // ===== Cold Path: Debug/Timing (1 variable) =====
+    int timing_enabled;              // HAKMEM_TIMING (default: 0)
+
 } HakEnvCache;
 
 // Global cache instance (initialized once at startup)
@@ -268,10 +271,17 @@ static inline void hakmem_env_cache_init(void) {
         g_hak_env_cache.smallmid_enable = (e && atoi(e) == 1) ? 1 : 0;  // default: 0 (OFF)
     }
 
+    // ===== Cold Path: Debug/Timing =====
+    {
+        const char* e;
+        e = getenv("HAKMEM_TIMING");
+        g_hak_env_cache.timing_enabled = (e && strcmp(e, "1") == 0) ? 1 : 0;  // default: 0 (OFF)
+    }
+
 #if !HAKMEM_BUILD_RELEASE
     // Debug: Print cache summary (stderr only)
     if (!g_hak_env_cache.quiet) {
-        fprintf(stderr, "[ENV_CACHE_INIT] Parsed %d ENV variables at startup\n", 47);
+        fprintf(stderr, "[ENV_CACHE_INIT] Parsed %d ENV variables at startup\n", 48);
         fprintf(stderr, "[ENV_CACHE_INIT] Hot path syscalls eliminated: ~2000/sec → 0/sec\n");
         fflush(stderr);
     }
@@ -334,4 +344,7 @@ static inline void hakmem_env_cache_init(void) {
 // Warm path: SmallMid
 #define HAK_ENV_SMALLMID_ENABLE()           (g_hak_env_cache.smallmid_enable)
 
+// Cold path: Debug/Timing
+#define HAK_ENV_TIMING_ENABLED()            (g_hak_env_cache.timing_enabled)
+
 #endif // HAKMEM_ENV_CACHE_H