parent/child mode

This commit is contained in:
Egor Aristov 2025-10-23 18:13:12 +03:00
parent ebb37ce5b8
commit 2b67cd1d01
Signed by: egor3f
GPG Key ID: 40482A264AAEC85F

View File

@ -21,138 +21,16 @@ const ipcSocketArg = "--ipc-socket"
type StdioMode int
type ipcMode int
const (
modeParent ipcMode = 1
modeChild ipcMode = 2
)
type KittenIPC struct {
mode ipcMode
cmd *exec.Cmd
type ipcCommon struct {
localApi any
socketPath string
listener net.Listener
conn net.Conn
errCh chan error
nextId int64
pendingCalls map[int64]chan callResult
mu sync.Mutex
}
func NewParent(cmd *exec.Cmd, localApi any) (*KittenIPC, error) {
k := KittenIPC{
mode: modeParent,
cmd: cmd,
localApi: localApi,
pendingCalls: make(map[int64]chan callResult),
errCh: make(chan error, 1),
}
k.socketPath = filepath.Join(os.TempDir(), fmt.Sprintf("kitten-ipc-%d.sock", os.Getpid()))
cmd.Stdout = os.Stdout
cmd.Stderr = os.Stderr
if slices.Contains(cmd.Args, ipcSocketArg) {
return nil, fmt.Errorf("you should not use `%s` argument in your command", ipcSocketArg)
}
cmd.Args = append(cmd.Args, ipcSocketArg, k.socketPath)
k.errCh = make(chan error, 1)
return &k, nil
}
func NewChild(localApi any) (*KittenIPC, error) {
k := KittenIPC{
mode: modeChild,
localApi: localApi,
pendingCalls: make(map[int64]chan callResult),
errCh: make(chan error, 1),
}
socketPath := flag.String("ipc-socket", "", "Path to IPC socket")
flag.Parse()
if *socketPath == "" {
return nil, fmt.Errorf("ipc socket path is missing")
}
k.socketPath = *socketPath
return &k, nil
}
func (k *KittenIPC) Start() error {
if k.mode == modeParent {
return k.startParent()
}
return k.startChild()
}
func (k *KittenIPC) startParent() error {
_ = os.Remove(k.socketPath)
listener, err := net.Listen("unix", k.socketPath)
if err != nil {
return fmt.Errorf("listen unix socket: %w", err)
}
k.listener = listener
defer k.closeSock()
err = k.cmd.Start()
if err != nil {
return fmt.Errorf("cmd start: %w", err)
}
if err := k.acceptConn(); err != nil {
return fmt.Errorf("accept connection: %w", err)
}
return nil
}
func (k *KittenIPC) startChild() error {
conn, err := net.Dial("unix", k.socketPath)
if err != nil {
return fmt.Errorf("connect to parent socket: %w", err)
}
k.conn = conn
k.startRcvData()
return nil
}
func (k *KittenIPC) acceptConn() error {
const acceptTimeout = time.Second * 10
res := make(chan mo.Result[net.Conn], 1)
go func() {
conn, err := k.listener.Accept()
if err != nil {
res <- mo.Err[net.Conn](err)
} else {
res <- mo.Ok[net.Conn](conn)
}
close(res)
}()
select {
case <-time.After(acceptTimeout):
_ = k.cmd.Process.Kill()
return fmt.Errorf("accept timeout")
case res := <-res:
if res.IsError() {
_ = k.cmd.Process.Kill()
return fmt.Errorf("accept: %w", res.Error())
}
k.conn = res.MustGet()
k.startRcvData()
}
return nil
}
type MsgType int
const (
@ -174,40 +52,40 @@ type callResult struct {
err error
}
func (k *KittenIPC) startRcvData() {
scn := bufio.NewScanner(k.conn)
func (ipc *ipcCommon) startRcvData() {
scn := bufio.NewScanner(ipc.conn)
for scn.Scan() {
var msg Message
if err := json.Unmarshal(scn.Bytes(), &msg); err != nil {
k.raiseErr(fmt.Errorf("unmarshal message: %w", err))
ipc.raiseErr(fmt.Errorf("unmarshal message: %w", err))
break
}
k.processMsg(msg)
ipc.processMsg(msg)
}
if err := scn.Err(); err != nil {
k.raiseErr(err)
ipc.raiseErr(err)
}
}
func (k *KittenIPC) processMsg(msg Message) {
func (ipc *ipcCommon) processMsg(msg Message) {
switch msg.Type {
case MsgCall:
k.handleCall(msg)
ipc.handleCall(msg)
case MsgResponse:
k.handleResponse(msg)
ipc.handleResponse(msg)
}
}
func (k *KittenIPC) handleCall(msg Message) {
func (ipc *ipcCommon) handleCall(msg Message) {
if k.localApi == nil {
k.sendResponse(msg.Id, nil, fmt.Errorf("remote side does not accept ipc calls"))
if ipc.localApi == nil {
ipc.sendResponse(msg.Id, nil, fmt.Errorf("remote side does not accept ipc calls"))
}
localApi := reflect.ValueOf(k.localApi)
localApi := reflect.ValueOf(ipc.localApi)
method := localApi.MethodByName(msg.Method)
if !method.IsValid() {
k.sendResponse(msg.Id, nil, fmt.Errorf("method not found: %s", msg.Method))
ipc.sendResponse(msg.Id, nil, fmt.Errorf("method not found: %s", msg.Method))
return
}
@ -215,7 +93,7 @@ func (k *KittenIPC) handleCall(msg Message) {
argsCount := methodType.NumIn()
if len(msg.Params) != argsCount {
k.sendResponse(msg.Id, nil, fmt.Errorf("argument count mismatch: expected %d, got %d", argsCount, len(msg.Params)))
ipc.sendResponse(msg.Id, nil, fmt.Errorf("argument count mismatch: expected %d, got %d", argsCount, len(msg.Params)))
return
}
@ -233,20 +111,20 @@ func (k *KittenIPC) handleCall(msg Message) {
res = append(res, resVal)
}
k.sendResponse(msg.Id, res, resErr.Interface().(error))
ipc.sendResponse(msg.Id, res, resErr.Interface().(error))
}
func (k *KittenIPC) handleResponse(msg Message) {
func (ipc *ipcCommon) handleResponse(msg Message) {
k.mu.Lock()
ch, ok := k.pendingCalls[msg.Id]
ipc.mu.Lock()
ch, ok := ipc.pendingCalls[msg.Id]
if ok {
delete(k.pendingCalls, msg.Id)
delete(ipc.pendingCalls, msg.Id)
}
k.mu.Unlock()
ipc.mu.Unlock()
if !ok {
k.raiseErr(fmt.Errorf("received response for unknown call id: %d", msg.Id))
ipc.raiseErr(fmt.Errorf("received response for unknown call id: %d", msg.Id))
return
}
@ -259,7 +137,7 @@ func (k *KittenIPC) handleResponse(msg Message) {
close(ch)
}
func (k *KittenIPC) sendResponse(id int64, result []any, err error) {
func (ipc *ipcCommon) sendResponse(id int64, result []any, err error) {
msg := Message{
Type: MsgResponse,
Id: id,
@ -270,12 +148,12 @@ func (k *KittenIPC) sendResponse(id int64, result []any, err error) {
msg.Error = err.Error()
}
if err := k.sendMsg(msg); err != nil {
k.raiseErr(fmt.Errorf("send response for id=%d: %w", id, err))
if err := ipc.sendMsg(msg); err != nil {
ipc.raiseErr(fmt.Errorf("send response for id=%d: %w", id, err))
}
}
func (k *KittenIPC) sendMsg(msg Message) error {
func (ipc *ipcCommon) sendMsg(msg Message) error {
data, err := json.Marshal(msg)
if err != nil {
@ -284,20 +162,20 @@ func (k *KittenIPC) sendMsg(msg Message) error {
data = append(data, '\n')
if _, err := k.conn.Write(data); err != nil {
if _, err := ipc.conn.Write(data); err != nil {
return fmt.Errorf("write message: %w", err)
}
return nil
}
func (k *KittenIPC) Call(method string, params ...any) ([]any, error) {
k.mu.Lock()
id := k.nextId
k.nextId++
func (ipc *ipcCommon) Call(method string, params ...any) ([]any, error) {
ipc.mu.Lock()
id := ipc.nextId
ipc.nextId++
resChan := make(chan callResult, 1)
k.pendingCalls[id] = resChan
k.mu.Unlock()
ipc.pendingCalls[id] = resChan
ipc.mu.Unlock()
msg := Message{
Type: MsgCall,
@ -306,10 +184,10 @@ func (k *KittenIPC) Call(method string, params ...any) ([]any, error) {
Params: params,
}
if err := k.sendMsg(msg); err != nil {
k.mu.Lock()
delete(k.pendingCalls, id)
k.mu.Unlock()
if err := ipc.sendMsg(msg); err != nil {
ipc.mu.Lock()
delete(ipc.pendingCalls, id)
ipc.mu.Unlock()
return nil, fmt.Errorf("send call: %w", err)
}
@ -317,38 +195,111 @@ func (k *KittenIPC) Call(method string, params ...any) ([]any, error) {
return result.result, result.err
}
func (k *KittenIPC) raiseErr(err error) {
func (ipc *ipcCommon) raiseErr(err error) {
select {
case k.errCh <- err:
case ipc.errCh <- err:
default:
}
}
func (k *KittenIPC) closeSock() error {
if err := k.listener.Close(); err != nil {
type ParentIPC struct {
*ipcCommon
cmd *exec.Cmd
listener net.Listener
}
func NewParent(cmd *exec.Cmd, localApi any) (*ParentIPC, error) {
p := ParentIPC{
ipcCommon: &ipcCommon{
localApi: localApi,
pendingCalls: make(map[int64]chan callResult),
errCh: make(chan error, 1),
socketPath: filepath.Join(os.TempDir(), fmt.Sprintf("kitten-ipc-%d.sock", os.Getpid())),
},
cmd: cmd,
}
cmd.Stdout = os.Stdout
cmd.Stderr = os.Stderr
if slices.Contains(cmd.Args, ipcSocketArg) {
return nil, fmt.Errorf("you should not use `%s` argument in your command", ipcSocketArg)
}
cmd.Args = append(cmd.Args, ipcSocketArg, p.socketPath)
p.errCh = make(chan error, 1)
return &p, nil
}
func (p *ParentIPC) Start() error {
_ = os.Remove(p.socketPath)
listener, err := net.Listen("unix", p.socketPath)
if err != nil {
return fmt.Errorf("listen unix socket: %w", err)
}
p.listener = listener
defer p.closeSock()
err = p.cmd.Start()
if err != nil {
return fmt.Errorf("cmd start: %w", err)
}
if err := p.acceptConn(); err != nil {
return fmt.Errorf("accept connection: %w", err)
}
return nil
}
func (p *ParentIPC) acceptConn() error {
const acceptTimeout = time.Second * 10
res := make(chan mo.Result[net.Conn], 1)
go func() {
conn, err := p.listener.Accept()
if err != nil {
res <- mo.Err[net.Conn](err)
} else {
res <- mo.Ok[net.Conn](conn)
}
close(res)
}()
select {
case <-time.After(acceptTimeout):
_ = p.cmd.Process.Kill()
return fmt.Errorf("accept timeout")
case res := <-res:
if res.IsError() {
_ = p.cmd.Process.Kill()
return fmt.Errorf("accept: %w", res.Error())
}
p.conn = res.MustGet()
p.startRcvData()
}
return nil
}
func (p *ParentIPC) closeSock() error {
if err := p.listener.Close(); err != nil {
return fmt.Errorf("close socket listener: %w", err)
}
return nil
}
func (k *KittenIPC) Wait() error {
if k.mode == modeParent {
return k.waitParent()
}
return k.waitChild()
}
func (k *KittenIPC) waitParent() error {
func (p *ParentIPC) Wait() error {
waitErrCh := make(chan error, 1)
go func() {
waitErrCh <- k.cmd.Wait()
waitErrCh <- p.cmd.Wait()
}()
select {
case err := <-k.errCh:
case err := <-p.errCh:
runtimeErr := fmt.Errorf("runtime error: %w", err)
killErr := k.cmd.Process.Kill()
killErr := p.cmd.Process.Kill()
return mergeErr(runtimeErr, killErr)
case err := <-waitErrCh:
if err != nil {
@ -359,8 +310,42 @@ func (k *KittenIPC) waitParent() error {
return nil
}
func (k *KittenIPC) waitChild() error {
err := <-k.errCh
type ChildIPC struct {
*ipcCommon
}
func NewChild(localApi any) (*ChildIPC, error) {
c := ChildIPC{
ipcCommon: &ipcCommon{
localApi: localApi,
pendingCalls: make(map[int64]chan callResult),
errCh: make(chan error, 1),
},
}
socketPath := flag.String("ipc-socket", "", "Path to IPC socket")
flag.Parse()
if *socketPath == "" {
return nil, fmt.Errorf("ipc socket path is missing")
}
c.socketPath = *socketPath
return &c, nil
}
func (c *ChildIPC) Start() error {
conn, err := net.Dial("unix", c.socketPath)
if err != nil {
return fmt.Errorf("connect to parent socket: %w", err)
}
c.conn = conn
c.startRcvData()
return nil
}
func (c *ChildIPC) Wait() error {
err := <-c.errCh
if err != nil {
return fmt.Errorf("ipc error: %w", err)
}