feat: Add Windows-compatible file locking for daemon

Replace Unix-only syscall.Flock with gofrs/flock library for
cross-platform file locking. This enables the daemon to run on
Windows in addition to Unix-like systems.

- Add github.com/gofrs/flock v0.13.0 dependency
- Replace syscall.Flock calls with flock.TryLock/Unlock
- Maintain same non-blocking exclusive lock semantics

(gt-5354h)

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
This commit is contained in:
gastown
2026-01-05 00:10:58 -08:00
committed by Steve Yegge
parent b88d3e8ee7
commit 43cca06460
3 changed files with 42 additions and 7 deletions

7
go.mod
View File

@@ -7,6 +7,8 @@ require (
github.com/charmbracelet/bubbles v0.21.0
github.com/charmbracelet/bubbletea v1.3.10
github.com/charmbracelet/lipgloss v1.1.0
github.com/go-rod/rod v0.116.2
github.com/gofrs/flock v0.13.0
github.com/google/uuid v1.6.0
github.com/spf13/cobra v1.10.2
golang.org/x/term v0.38.0
@@ -34,5 +36,10 @@ require (
github.com/rivo/uniseg v0.4.7 // indirect
github.com/spf13/pflag v1.0.9 // indirect
github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e // indirect
github.com/ysmood/fetchup v0.2.3 // indirect
github.com/ysmood/goob v0.4.0 // indirect
github.com/ysmood/got v0.40.0 // indirect
github.com/ysmood/gson v0.7.3 // indirect
github.com/ysmood/leakless v0.9.0 // indirect
golang.org/x/sys v0.39.0 // indirect
)

26
go.sum
View File

@@ -27,8 +27,14 @@ github.com/clipperhouse/stringish v0.1.1/go.mod h1:v/WhFtE1q0ovMta2+m+UbpZ+2/HEX
github.com/clipperhouse/uax29/v2 v2.3.0 h1:SNdx9DVUqMoBuBoW3iLOj4FQv3dN5mDtuqwuhIGpJy4=
github.com/clipperhouse/uax29/v2 v2.3.0/go.mod h1:Wn1g7MK6OoeDT0vL+Q0SQLDz/KpfsVRgg6W7ihQeh4g=
github.com/cpuguy83/go-md2man/v2 v2.0.6/go.mod h1:oOW0eioCTA6cOiMLiUPZOpcVxMig6NIQQ7OS05n1F4g=
github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/erikgeiser/coninput v0.0.0-20211004153227-1c3628e74d0f h1:Y/CXytFA4m6baUTXGLOoWe4PQhGxaX0KpnayAqC48p4=
github.com/erikgeiser/coninput v0.0.0-20211004153227-1c3628e74d0f/go.mod h1:vw97MGsxSvLiUE2X8qFplwetxpGLQrlU1Q9AUEIzCaM=
github.com/go-rod/rod v0.116.2 h1:A5t2Ky2A+5eD/ZJQr1EfsQSe5rms5Xof/qj296e+ZqA=
github.com/go-rod/rod v0.116.2/go.mod h1:H+CMO9SCNc2TJ2WfrG+pKhITz57uGNYU43qYHh438Mg=
github.com/gofrs/flock v0.13.0 h1:95JolYOvGMqeH31+FC7D2+uULf6mG61mEZ/A8dRYMzw=
github.com/gofrs/flock v0.13.0/go.mod h1:jxeyy9R1auM5S6JYDBhDt+E2TCo7DkratH4Pgi8P+Z0=
github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
@@ -47,6 +53,8 @@ github.com/muesli/cancelreader v0.2.2 h1:3I4Kt4BQjOR54NavqnDogx/MIoWBFa0StPA8ELU
github.com/muesli/cancelreader v0.2.2/go.mod h1:3XuTXfFS2VjM+HTLZY9Ak0l6eUKfijIfMUZ4EgX0QYo=
github.com/muesli/termenv v0.16.0 h1:S5AlUN9dENB57rsbnkPyfdGuWIlkmzJjbFf0Tf5FWUc=
github.com/muesli/termenv v0.16.0/go.mod h1:ZRfOIKPFDYQoDFF4Olj7/QJbW60Ol/kL1pU3VfY/Cnk=
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/rivo/uniseg v0.4.7 h1:WUdvkW8uEhrYfLC4ZzdpI2ztxP1I582+49Oc5Mq64VQ=
github.com/rivo/uniseg v0.4.7/go.mod h1:FN3SvrM+Zdj16jyLfmOkMNblXMcoc8DfTHruCPUcx88=
github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
@@ -54,8 +62,24 @@ github.com/spf13/cobra v1.10.2 h1:DMTTonx5m65Ic0GOoRY2c16WCbHxOOw6xxezuLaBpcU=
github.com/spf13/cobra v1.10.2/go.mod h1:7C1pvHqHw5A4vrJfjNwvOdzYu0Gml16OCs2GRiTUUS4=
github.com/spf13/pflag v1.0.9 h1:9exaQaMOCwffKiiiYk6/BndUBv+iRViNW+4lEMi0PvY=
github.com/spf13/pflag v1.0.9/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e h1:JVG44RsyaB9T2KIHavMF/ppJZNG9ZpyihvCd0w101no=
github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e/go.mod h1:RbqR21r5mrJuqunuUZ/Dhy/avygyECGrLceyNeo4LiM=
github.com/ysmood/fetchup v0.2.3 h1:ulX+SonA0Vma5zUFXtv52Kzip/xe7aj4vqT5AJwQ+ZQ=
github.com/ysmood/fetchup v0.2.3/go.mod h1:xhibcRKziSvol0H1/pj33dnKrYyI2ebIvz5cOOkYGns=
github.com/ysmood/goob v0.4.0 h1:HsxXhyLBeGzWXnqVKtmT9qM7EuVs/XOgkX7T6r1o1AQ=
github.com/ysmood/goob v0.4.0/go.mod h1:u6yx7ZhS4Exf2MwciFr6nIM8knHQIE22lFpWHnfql18=
github.com/ysmood/gop v0.2.0 h1:+tFrG0TWPxT6p9ZaZs+VY+opCvHU8/3Fk6BaNv6kqKg=
github.com/ysmood/gop v0.2.0/go.mod h1:rr5z2z27oGEbyB787hpEcx4ab8cCiPnKxn0SUHt6xzk=
github.com/ysmood/got v0.40.0 h1:ZQk1B55zIvS7zflRrkGfPDrPG3d7+JOza1ZkNxcc74Q=
github.com/ysmood/got v0.40.0/go.mod h1:W7DdpuX6skL3NszLmAsC5hT7JAhuLZhByVzHTq874Qg=
github.com/ysmood/gotrace v0.6.0 h1:SyI1d4jclswLhg7SWTL6os3L1WOKeNn/ZtzVQF8QmdY=
github.com/ysmood/gotrace v0.6.0/go.mod h1:TzhIG7nHDry5//eYZDYcTzuJLYQIkykJzCRIo4/dzQM=
github.com/ysmood/gson v0.7.3 h1:QFkWbTH8MxyUTKPkVWAENJhxqdBa4lYTQWqZCiLG6kE=
github.com/ysmood/gson v0.7.3/go.mod h1:3Kzs5zDl21g5F/BlLTNcuAGAYLKt2lV5G8D1zF3RNmg=
github.com/ysmood/leakless v0.9.0 h1:qxCG5VirSBvmi3uynXFkcnLMzkphdh3xx5FtrORwDCU=
github.com/ysmood/leakless v0.9.0/go.mod h1:R8iAXPRaG97QJwqxs74RdwzcRHT1SWCGTNqY8q0JvMQ=
go.yaml.in/yaml/v3 v3.0.4/go.mod h1:DhzuOOF2ATzADvBadXxruRBLzYTpT36CKvDb3+aBEFg=
golang.org/x/exp v0.0.0-20231006140011-7918f672742d h1:jtJma62tbqLibJ5sFQz8bKtEM8rJBtfilJ2qTU199MI=
golang.org/x/exp v0.0.0-20231006140011-7918f672742d/go.mod h1:ldy0pHrwJyGW56pPQzzkH36rKxoZW1tw7ZJpeKx+hdo=
@@ -68,3 +92,5 @@ golang.org/x/term v0.38.0/go.mod h1:bSEAKrOT1W+VSu9TSCMtoGEOUcKxOKgl3LE5QEF/xVg=
golang.org/x/text v0.32.0 h1:ZD01bjUt1FQ9WJ0ClOL5vxgxOI/sVCNgX1YtKwcY0mU=
golang.org/x/text v0.32.0/go.mod h1:o/rUWzghvpD5TXrTIBuJU77MTaN0ljMWE47kxGJQ7jY=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

View File

@@ -13,6 +13,7 @@ import (
"syscall"
"time"
"github.com/gofrs/flock"
"github.com/steveyegge/gastown/internal/beads"
"github.com/steveyegge/gastown/internal/boot"
"github.com/steveyegge/gastown/internal/config"
@@ -70,18 +71,19 @@ func (d *Daemon) Run() error {
// Acquire exclusive lock to prevent multiple daemons from running.
// This prevents the TOCTOU race condition where multiple concurrent starts
// can all pass the IsRunning() check before any writes the PID file.
// Uses gofrs/flock for cross-platform compatibility (Unix + Windows).
lockFile := filepath.Join(d.config.TownRoot, "daemon", "daemon.lock")
lock, err := os.OpenFile(lockFile, os.O_CREATE|os.O_RDWR, 0644)
if err != nil {
return fmt.Errorf("opening lock file: %w", err)
}
defer lock.Close()
fileLock := flock.New(lockFile)
// Try to acquire exclusive lock (non-blocking)
if err := syscall.Flock(int(lock.Fd()), syscall.LOCK_EX|syscall.LOCK_NB); err != nil {
locked, err := fileLock.TryLock()
if err != nil {
return fmt.Errorf("acquiring lock: %w", err)
}
if !locked {
return fmt.Errorf("daemon already running (lock held by another process)")
}
defer func() { _ = syscall.Flock(int(lock.Fd()), syscall.LOCK_UN) }()
defer fileLock.Unlock()
// Write PID file
if err := os.WriteFile(d.config.PidFile, []byte(strconv.Itoa(os.Getpid())), 0644); err != nil {