Boxify superslab registry, add bench profile, and document C7 hotpath experiments

core/box/shared_pool_box.c

@@ -0,0 +1,50 @@
+#include "shared_pool_box.h"
+
+#include <stdatomic.h>
+#include <stdlib.h>
+#include <string.h>
+
+// 既存の g_shared_pool 配列上に「論理的な上限」だけを被せる。
+static _Atomic uint32_t g_sp_total_limit = 0;       // 0 = 無制限（現行のまま）
+static _Atomic uint32_t g_sp_class_limit = 0;       // 0 = 無制限
+static _Atomic int g_sp_profile_inited = 0;
+
+static void shared_pool_apply_profile(const char* profile) {
+    if (g_sp_profile_inited) {
+        return;
+    }
+    const char* env_profile = profile ? profile : getenv("HAKMEM_PROFILE");
+    int is_bench = (env_profile && strcmp(env_profile, "bench") == 0);
+
+    uint32_t total_limit = 0;
+    uint32_t class_limit = 0;
+    if (is_bench) {
+        // bench 用: ひとまず控えめな論理上限だけ入れる
+        total_limit = 65536;  // 元の 1M よりかなり少ない
+        class_limit = 2048;   // クラスあたりの active slot 上限の目安
+    }
+
+    atomic_store_explicit(&g_sp_total_limit, total_limit, memory_order_relaxed);
+    atomic_store_explicit(&g_sp_class_limit, class_limit, memory_order_relaxed);
+    atomic_store_explicit(&g_sp_profile_inited, 1, memory_order_release);
+}
+
+void shared_pool_box_init(SharedPoolBox* box, const char* profile) {
+    (void)box;
+    shared_pool_apply_profile(profile);
+}
+
+uint32_t shared_pool_effective_total_slots(void) {
+    if (!atomic_load_explicit(&g_sp_profile_inited, memory_order_acquire)) {
+        shared_pool_apply_profile(NULL);
+    }
+    return atomic_load_explicit(&g_sp_total_limit, memory_order_relaxed);
+}
+
+uint32_t shared_pool_effective_class_slots(int class_idx) {
+    (void)class_idx;
+    if (!atomic_load_explicit(&g_sp_profile_inited, memory_order_acquire)) {
+        shared_pool_apply_profile(NULL);
+    }
+    return atomic_load_explicit(&g_sp_class_limit, memory_order_relaxed);
+}