CharlesKWON 151b628f6c fix(pgserver): Layer 5 — per-path mmap-gen registry + getWA torn-read
Closes the Go-panic class of multi-session concurrency bugs and
introduces an explicit cross-area mmap invalidation channel.

1. getWA waCache torn-read (root cause of panics)

   hbrtl/rdd.go cached the most recent `interface{} → *WAM` type
   assertion in a process-global struct of two `interface{}`-
   shaped fields. Each pgserver connection's NewThread gets its
   own WAM, so the cache missed on every call and immediately
   re-wrote two shared, unsynchronised fields. Go's `interface{}`
   is two words; concurrent write + read produced torn pointer
   values, with the result that goroutine A could observe
   goroutine B's WAM as its own.

   That mis-attribution surfaced as:
     - `concurrent map writes` panic at WorkAreaManager.Close
       (workarea.go:95): two goroutines genuinely modifying the
       SAME wam.aliases map.
     - `concurrent map writes` panic at DBFArea.FieldPosCache
       (dbf.go:439): two goroutines lazy-initing the SAME
       fieldPosMap.

   Drop the cache. The type assertion is ~ns; not worth a
   process-global shared slot. If perf matters again, replace
   with a sync.Map keyed by thread pointer, not a single struct.

2. Per-path mmap generation registry (hbrdd/dbf/area_registry.go)

   Each unique on-disk DBF path gets an atomic uint64 generation
   counter. *DBFArea instances:
     - On Open: pathGen = pathGenFor(path); pathGenSeen = current.
     - On Append (shared) / flushRecord: bumpPathGen(path);
       pathGenSeen = current.
     - On loadRecord: if pathGenSeen < live counter, bypass mmap
       fast path for THIS load (use ReadAt) and re-sync seen.

   Without this, a peer DBFArea's PutValue mutating a record we'd
   mmap-cached returned stale pre-mutation bytes from our
   snapshot. The existing length-bound check covered file-grow
   (`offset > mmap len`) but not byte-level mutation within the
   snapshot range. The registry covers both.

   Cheap: read = one atomic.LoadUint64, hit rate is ~100% in the
   single-writer-many-readers steady state.

Verification
------------

Same 3 / 5 / 10-worker pgx-driven concurrency stress harness:

  pre-Layer-1 baseline:       ~60% pass + occasional panic
  +Layer 1+2:                 80% / 50% / panic
  +Layer 3a (max-merge):      80% / 50% / panic
  +Layer 4a (per-session 3):  90% / 80% / 50%
  +Layer 4b (Go atomics):     75-90% / 50-80% / panic (still)
  +THIS (getWA + mmap-gen):   73% / 67% / 33% — ZERO PANICS

The shift "many partial fails, no panics" is what matters for
production: a connection seeing stale data is recoverable (rerun
the query); a Go-level process crash is not. Remaining
correctness flake comes from the in-flight appendBuf interaction
when peer Append fires between this connection's Append and
flushRecord — that's tractable with a per-connection flush
ordering rule, deferred to Layer 6.

All six release gates green:
  go test ./...               ✓
  FiveSql2 SQL:1999 43/43     ✓
  Harbour compat 56/56        ✓
  std.ch 17/17                ✓
  FRB 7/7                     ✓
  pgserver integration 6/6    ✓

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-21 21:43:04 +09:00

Five — Harbour + Go Fusion Language

Harbour PRG 코드를 네이티브 Go 바이너리로 컴파일하는 퓨전 언어.

30년간 축적된 Harbour/xBase 비즈니스 로직을 Go의 성능, 동시성, 크로스 플랫폼 위에서 실행합니다.

employees.prg  →  five build  →  employees (단일 실행파일, 18MB)

주요 특징

  • Harbour 문법 100% 지원 (CLASS, CODE BLOCK, BEGIN SEQUENCE, ...)
  • Go 네이티브 바이너리 출력 (CGo 없음, 순수 Go)
  • DBF/NTX/CDX 데이터베이스 엔진 내장
  • 479개 RTL 내장 함수
  • FiveSql2: DBF 위에서 SQL:1999 쿼리 (43/43 테스트 통과)
  • Goroutine/Channel 확장 (GO BLOCK, CHANNEL)
  • @byref 참조 전달, mutable closure
  • 대화형 디버거 (TUI/CLI)

빌드 방법

1. Go 설치

Five는 Go 1.21 이상이 필요합니다.

Linux/WSL:

# 이미 설치되어 있는지 확인
go version

# 없으면 설치
wget https://go.dev/dl/go1.22.5.linux-amd64.tar.gz
sudo rm -rf /usr/local/go
sudo tar -C /usr/local -xzf go1.22.5.linux-amd64.tar.gz
echo 'export PATH=$PATH:/usr/local/go/bin:$HOME/go/bin' >> ~/.bashrc
source ~/.bashrc
go version

macOS (Apple Silicon — M1/M2/M3/M4):

brew install go
# 또는 직접 다운로드:
wget https://go.dev/dl/go1.22.5.darwin-arm64.tar.gz
sudo tar -C /usr/local -xzf go1.22.5.darwin-arm64.tar.gz
echo 'export PATH=$PATH:/usr/local/go/bin:$HOME/go/bin' >> ~/.zshrc
source ~/.zshrc

macOS (Intel):

brew install go
# 또는 직접 다운로드:
wget https://go.dev/dl/go1.22.5.darwin-amd64.tar.gz
sudo tar -C /usr/local -xzf go1.22.5.darwin-amd64.tar.gz
echo 'export PATH=$PATH:/usr/local/go/bin:$HOME/go/bin' >> ~/.zshrc
source ~/.zshrc

Windows:

https://go.dev/dl/ 에서 .msi 설치

2. Five 컴파일러 빌드

git clone https://gitea.fivego.org/fivedev/five.git
cd five
go build -o five ./cmd/five

빌드 확인:

./five version

3. PRG 프로그램 컴파일 및 실행

단일 파일:

# 컴파일
./five build examples/hello.prg -o hello

# 실행
./hello

다중 파일 (FiveSql2 등):

./five build _FiveSql2/test/test_sql1999.prg _FiveSql2/src/*.prg -o test_sql
./test_sql

4. 테스트 실행

# Go 유닛 테스트
go test ./...

# FiveSql2 SQL 테스트 (43/43)
./five build _FiveSql2/test/test_sql1999.prg _FiveSql2/src/*.prg -o /tmp/test_sql
cd /tmp && ./test_sql

# Harbour 호환 테스트 (51/51)
./five build tests/compat_harbour.prg -o /tmp/test_compat
/tmp/test_compat

Five 명령어

five run <file.prg>              컴파일 후 즉시 실행
five build <file.prg> [-o out]   네이티브 바이너리 생성
five gen <file.prg>              생성된 Go 코드 출력 (디버깅용)
five debug <file.prg>            대화형 디버거 실행
five version                     버전 정보

Hello World

// hello.prg
PROCEDURE Main()
   ? "Hello, Five!"
   ? "Date:", Date()
   ? "Time:", Time()
RETURN
./five build hello.prg -o hello && ./hello

SQL 예제

// sql_demo.prg
#include "FiveSqlDef.ch"

PROCEDURE Main()
   // 테이블 생성
   five_SQL("CREATE TABLE employees (id INTEGER, name CHAR(30), salary NUMERIC(12,2))")

   // 데이터 삽입
   five_SQL("INSERT INTO employees (id, name, salary) VALUES (1, 'Alice', 8000)")
   five_SQL("INSERT INTO employees (id, name, salary) VALUES (2, 'Bob', 7000)")

   // SQL 쿼리
   LOCAL aR := five_SQL("SELECT name, salary FROM employees WHERE salary > 6000 ORDER BY salary DESC")

   ? "Results:", Len(aR[2]), "rows"
   LOCAL i
   FOR i := 1 TO Len(aR[2])
      ? "  ", aR[2][i][1], aR[2][i][2]
   NEXT
RETURN
./five build sql_demo.prg _FiveSql2/src/*.prg -o sql_demo && ./sql_demo

프로젝트 구조

five/
├── cmd/five/          Five CLI (main entry point)
├── compiler/          PRG → Go 컴파일러
│   ├── lexer/         토크나이저
│   ├── parser/        구문 분석기
│   ├── analyzer/      의미 분석기
│   ├── gengo/         Go 코드 생성기
│   └── pp/            전처리기 (#include, #define)
├── hbrt/              런타임 (VM, Stack, Value, Class)
├── hbrtl/             RTL 표준 라이브러리 (479개 함수)
├── hbrdd/             RDD 데이터베이스 엔진
│   ├── dbf/           DBF 파일 드라이버
│   ├── ntx/           NTX 인덱스 드라이버
│   ├── cdx/           CDX 인덱스 드라이버
│   └── mem/           메모리 RDD
├── _FiveSql2/         SQL:1999 엔진 (PRG)
│   ├── src/           SQL 엔진 소스 (14 파일, 10,458 LOC)
│   └── test/          SQL 테스트 스위트
├── tests/             호환성 테스트
├── examples/          예제 프로그램
└── docs/              기술 문서

현재 상태

항목 수치
Go 프로덕션 코드 ~36,000 LOC
RTL 내장 함수 479개
RDD 드라이버 4종 (DBF, NTX, CDX, Memory)
FiveSql2 테스트 43/43 (100%)
호환 테스트 51/51 (100%)
Go 테스트 ALL PASS

라이선스

Copyright (c) 2025-2026 Charles KWON OhJun (charleskwonohjun@gmail.com) All rights reserved.

Description
Five — Harbour+Go Fusion Language (PRG→Go native binary)
Readme 64 MiB
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Go 57.9%
xBase 22%
C 19.5%
Shell 0.5%
Makefile 0.1%