From 8eda018475a9354e9700b65b5d5a42a6ea8e4cfe Mon Sep 17 00:00:00 2001
From: "Moe Charm (CI)" <moecharm@example.com>
Date: Sat, 8 Nov 2025 01:48:40 +0900
Subject: [PATCH] Doc: Unify debug logging policy with HAKMEM_BUILD_RELEASE
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Policy:
=======
All diagnostic logging must be controlled by HAKMEM_BUILD_RELEASE flag.

Build Modes:
- Release (HAKMEM_BUILD_RELEASE=1): All diagnostics disabled
- Debug (HAKMEM_BUILD_RELEASE=0): Diagnostics enabled (env var controlled)

Implementation Pattern:
- Use guard functions that check HAKMEM_BUILD_RELEASE at compile time
- Example: trc_refill_guard_enabled() (already implemented)
- Avoid direct fprintf() calls in hot paths

Status:
- ✅ Hot path (refill) unified with trc_refill_guard_enabled()
- ⏳ 92 other diagnostic locations to convert as needed
- 📊 Result: +3.1% performance improvement

See DEBUG_LOGGING_POLICY.md for full guidelines.

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

Co-Authored-By: Claude <noreply@anthropic.com>
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 DEBUG_LOGGING_POLICY.md | 95 +++++++++++++++++++++++++++++++++++++++++
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 create mode 100644 DEBUG_LOGGING_POLICY.md

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+# Debug Logging Policy
+
+## 統一方針
+
+すべての診断ログは **`HAKMEM_BUILD_RELEASE`** フラグで統一的に制御する。
+
+### Build Modes
+
+- **Release Build** (`HAKMEM_BUILD_RELEASE=1`): 診断ログ完全無効（性能最優先）
+  - `-DNDEBUG` が定義されると自動的に有効
+  - 本番環境・ベンチマーク用
+
+- **Debug Build** (`HAKMEM_BUILD_RELEASE=0`): 診断ログ有効（デバッグ用）
+  - デフォルト（NDEBUG未定義）
+  - 環境変数で細かく制御可能
+
+### Implementation Pattern
+
+#### ✅ 推奨パターン（Guard関数）
+
+```c
+static inline int diagnostic_enabled(void) {
+#if HAKMEM_BUILD_RELEASE
+    return 0;  // Always disabled in release
+#else
+    // Check env var in debug builds
+    static int enabled = -1;
+    if (__builtin_expect(enabled == -1, 0)) {
+        const char* env = getenv("HAKMEM_DEBUG_FEATURE");
+        enabled = (env && *env != '0') ? 1 : 0;
+    }
+    return enabled;
+#endif
+}
+
+// Usage
+if (__builtin_expect(diagnostic_enabled(), 0)) {
+    fprintf(stderr, "[DEBUG] ...\n");
+}
+```
+
+#### ❌ 避けるパターン
+
+```c
+// 悪い例：環境変数を毎回チェック（getenv() は遅い）
+const char* env = getenv("HAKMEM_DEBUG");
+if (env && *env != '0') {
+    fprintf(stderr, "...\n");
+}
+
+// 悪い例：無条件ログ（release でも出力される）
+fprintf(stderr, "[DEBUG] ...\n");
+```
+
+### Existing Guard Functions
+
+| 関数 | 用途 | ファイル |
+|------|------|---------|
+| `trc_refill_guard_enabled()` | Refill path 診断 | `core/tiny_refill_opt.h` |
+| `g_debug_remote_guard` | Remote queue 診断 | `core/superslab/superslab_inline.h` |
+| `tiny_refill_failfast_level()` | Fail-fast 検証 | `core/hakmem_tiny_free.inc` |
+
+### Priority for Conversion
+
+1. **🔥 Hot Path (最優先)**: Refill, Alloc, Free の fast path ✅ 完了
+2. **⚠️ Medium**: Remote drain, Magazine 層
+3. **✅ Low**: Initialization, Slow path
+
+### Status
+
+- ✅ `trc_refill_guard_enabled()` - Release build で完全無効化
+- ⏳ 残り 92 箇所 - 必要に応じて対処
+
+### Makefile Integration
+
+現状：`NDEBUG` が定義されていない → `HAKMEM_BUILD_RELEASE=0`
+
+TODO: Release ビルドターゲットに `-DNDEBUG` を追加
+```makefile
+release: CFLAGS += -DNDEBUG -O3
+```
+
+### Environment Variables (Debug Build Only)
+
+- `HAKMEM_TINY_REFILL_FAILFAST`: Refill path 検証 (0=off, 1=on, 2=verbose)
+- `HAKMEM_TINY_REFILL_OPT_DEBUG`: Refill 最適化ログ
+- `HAKMEM_DEBUG_REMOTE_GUARD`: Remote queue 検証
+
+## Performance Impact
+
+| 状態 | Throughput | 改善 |
+|------|-----------|------|
+| Before (診断あり) | 1,015,347 ops/s | - |
+| After (guard追加) | 1,046,392 ops/s | **+3.1%** |
+| Target (完全無効化) | TBD | 推定 +5-10% |