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

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

【置換ファイル】
- core/hakmem_batch.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 (48→49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: 48→49

2. hakmem_batch.c:
   - batch_init():
     getenv("HAKMEM_BATCH_BG") → HAK_ENV_BATCH_BG()
   - #include "hakmem_env_cache.h" 追加

【効果】
- Batch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_batch.c

@@ -10,6 +10,7 @@
 #include "hakmem_batch.h"
 #include "hakmem_sys.h"        // Phase 6.11.1: Syscall wrappers with timing
 #include "hakmem_whale.h"      // Phase 6.11.1: Whale fast-path cache
+#include "hakmem_env_cache.h"  // Priority-2: ENV cache
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
@@ -70,8 +71,8 @@ void hak_batch_init(void) {
     g_immediate_dontneed = 0;
 
     // Background worker toggle
-    const char* e_bg = getenv("HAKMEM_BATCH_BG");
-    if (e_bg) g_bg_enabled = (atoi(e_bg) != 0);
+    // Priority-2: Use cached ENV
+    g_bg_enabled = HAK_ENV_BATCH_BG();
 
     // Sync primitives
     pthread_mutex_init(&g_batch_mu, NULL);

core/hakmem_env_cache.h

@@ -87,6 +87,9 @@ typedef struct {
     // ===== Cold Path: Debug/Timing (1 variable) =====
     int timing_enabled;              // HAKMEM_TIMING (default: 0)
 
+    // ===== Cold Path: Batch (1 variable) =====
+    int batch_bg;                    // HAKMEM_BATCH_BG (default: 0)
+
 } HakEnvCache;
 
 // Global cache instance (initialized once at startup)
@@ -278,10 +281,17 @@ static inline void hakmem_env_cache_init(void) {
         g_hak_env_cache.timing_enabled = (e && strcmp(e, "1") == 0) ? 1 : 0;  // default: 0 (OFF)
     }
 
+    // ===== Cold Path: Batch =====
+    {
+        const char* e;
+        e = getenv("HAKMEM_BATCH_BG");
+        g_hak_env_cache.batch_bg = (e && atoi(e) != 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", 48);
+        fprintf(stderr, "[ENV_CACHE_INIT] Parsed %d ENV variables at startup\n", 49);
         fprintf(stderr, "[ENV_CACHE_INIT] Hot path syscalls eliminated: ~2000/sec → 0/sec\n");
         fflush(stderr);
     }
@@ -347,4 +357,7 @@ static inline void hakmem_env_cache_init(void) {
 // Cold path: Debug/Timing
 #define HAK_ENV_TIMING_ENABLED()            (g_hak_env_cache.timing_enabled)
 
+// Cold path: Batch
+#define HAK_ENV_BATCH_BG()                  (g_hak_env_cache.batch_bg)
+
 #endif // HAKMEM_ENV_CACHE_H