add VsockCidAllocator in unsuppported os

Signed-off-by: Allen Sun <[email protected]>

Author: allencloud

Diff for: lib/vsock/vsock_unsupported.go

@@ -5,8 +5,16 @@ package vsock
 import (
 	"fmt"
 	"net"
+	"sync"
 )
 
+type VsockCidAllocator interface {
+	sync.Locker
+	GetCid() (uint32, error)
+	MarkCidInuse(uint32) bool
+	ReleaseCid(uint32)
+}
+
 func Dial(cid uint32, port uint32) (net.Conn, error) {
 	return nil, fmt.Errorf("vsock is not supported")
 }