(Sync Commit)

app/proxyman/inbound/unix.go

@@ -23,7 +23,10 @@ type UnixInboundHandler struct {
 func (uih *UnixInboundHandler) Start() {
 	var err error
 	uih.listenerHolder, err = domainsocket.ListenDS(uih.ctx, uih.path)
-	newError(err).AtError().WriteToLog()
+	if err != nil {
+		newError(err).AtError().WriteToLog()
+	}
+
 }
 func (uih *UnixInboundHandler) Close() {
 	if uih.listenerHolder != nil {

transport/internet/domainsocket/listener.go

@@ -3,24 +3,75 @@ package domainsocket
 import (
 	"context"
 	"net"
+	"os"
+	"syscall"
 )
 
 type Listener struct {
-	ln net.Listener
+	ln           net.Listener
+	listenerChan <-chan net.Conn
+	ctx          context.Context
+	path         string
+	lockfile     os.File
 }
 
 func ListenDS(ctx context.Context, path string) (*Listener, error) {
+
+	vln := &Listener{path: path}
+	return vln, nil
+}
+
+func (ls *Listener) Down() error {
+	err := ls.ln.Close()
+	if err != nil {
+		newError(err).AtDebug().WriteToLog()
+	}
+	return err
+}
+
+//Setup systen level Listener
+func (ls *Listener) LowerUP() error {
+
+	if isUnixDomainSocketFileSystemBased(ls.path) && !___DEBUG_IGNORE_FLOCK {
+
+	}
+
 	addr := new(net.UnixAddr)
-	addr.Name = path
+	addr.Name = ls.path
 	addr.Net = "unix"
 	li, err := net.ListenUnix("unix", addr)
 	if err != nil {
-		return nil, err
+		return err
 	}
-	vln := &Listener{ln: li}
-	return vln, nil
+
 }
 
-func (ls *Listener) Down() {
-	ls.ln.Close()
+func isUnixDomainSocketFileSystemBased(path string) bool {
+	//No Branching
+	return path[0] != 0
 }
+
+func AcquireLock(lockfilepath string) (*os.File, error) {
+	f, err := os.Create(lockfilepath)
+	if err != nil {
+		newError(err).AtDebug().WriteToLog()
+		return f, err
+	}
+	err = syscall.Flock(int(f.Fd()), syscall.LOCK_EX)
+	if err != nil {
+		newError(err).AtDebug().WriteToLog()
+		err = f.Close()
+		if err != nil {
+			if ___DEBUG_PANIC_WHEN_ENCOUNTED_IMPOSSIBLE_ERROR {
+				panic(err)
+			}
+			newError(err).AtDebug().WriteToLog()
+		}
+		return nil, err
+	}
+}
+
+//DEBUG CONSTS
+const ___DEBUG_IGNORE_FLOCK = false
+const ___DEBUG_PANIC_WHEN_ERROR_UNPROPAGATEABLE = false
+const ___DEBUG_PANIC_WHEN_ENCOUNTED_IMPOSSIBLE_ERROR = false