diff --git a/subdomains/safe_map.go b/subdomains/safe_map.go
new file mode 100644
index 0000000..908074b
--- /dev/null
+++ b/subdomains/safe_map.go
@@ -0,0 +1,71 @@
+package subdomains
+
+import "sync"
+
+func InitSafeMap[T any]() SafeMap[T] {
+	return SafeMap[T]{mp: map[string]T{}}
+}
+
+func NewSafeMap[T any]() *SafeMap[T] {
+	return &SafeMap[T]{mp: map[string]T{}}
+}
+
+type SafeMap[T any] struct {
+	mu sync.RWMutex
+	mp map[string]T
+}
+
+func (a *SafeMap[T]) Size() int {
+	a.mu.RLock()
+	size := len(a.mp)
+	a.mu.RUnlock()
+	return size
+}
+
+func (a *SafeMap[T]) GetOk(key string) (T, bool) {
+	a.mu.RLock()
+	val, ok := a.mp[key]
+	a.mu.RUnlock()
+	return val, ok
+}
+
+func (a *SafeMap[T]) Get(key string) T {
+	a.mu.RLock()
+	val := a.mp[key]
+	a.mu.RUnlock()
+	return val
+}
+
+func (a *SafeMap[T]) Set(key string, info T) {
+	a.mu.Lock()
+	a.mp[key] = info
+	a.mu.Unlock()
+}
+
+func (a *SafeMap[T]) Remove(keys ...string) {
+	a.mu.Lock()
+	for _, key := range keys {
+		delete(a.mp, key)
+	}
+	a.mu.Unlock()
+}
+
+func (a *SafeMap[T]) Range(f func(key string, val T) bool) {
+	a.mu.RLock()
+	for key, val := range a.mp {
+		if !f(key, val) {
+			break
+		}
+	}
+	a.mu.RUnlock()
+}
+
+func (a *SafeMap[T]) ClearEmpty(f func(key string, val T) bool) {
+	a.mu.Lock()
+	for key, val := range a.mp {
+		if f(key, val) {
+			delete(a.mp, key)
+		}
+	}
+	a.mu.Unlock()
+}
diff --git a/subdomains/subdomains.go b/subdomains/subdomains.go
index cd631b3..c21ccc3 100644
--- a/subdomains/subdomains.go
+++ b/subdomains/subdomains.go
@@ -1,8 +1,10 @@
 package subdomains
 
 import (
+	"slices"
 	"sort"
 	"strings"
+	"sync/atomic"
 
 	"github.com/admpub/log"
 
@@ -17,8 +19,8 @@ var Default = New()
 
 func New() *Subdomains {
 	s := &Subdomains{
-		Hosts:    map[string][]string{},
-		Alias:    map[string]*Info{},
+		Hosts:    InitSafeMap[*[]string](),
+		Alias:    InitSafeMap[*Info](),
 		Default:  ``,
 		Protocol: `http`,
 	}
@@ -75,9 +77,10 @@ func (info *Info) RelativeURLByName(s *Subdomains, name string, args ...interfac
 type Dispatcher func(r engine.Request, w engine.Response) (*echo.Echo, bool)
 
 type Subdomains struct {
-	Hosts      map[string][]string //{host:name}
-	Alias      map[string]*Info
+	Hosts      SafeMap[*[]string] //{host:name}
+	Alias      SafeMap[*Info]
 	Prefixes   []string
+	hostsNum   atomic.Int32
 	Default    string //default name
 	Protocol   string //http/https
 	Boot       string
@@ -109,13 +112,34 @@ func (s *Subdomains) Add(name string, e *echo.Echo) *Subdomains {
 			hosts = append(hosts, ``)
 		}
 	}
+	var hasRemoved bool
+	var addedHosts int
+	var appendsHosts []string
 	for _, host := range hosts {
-		if _, ok := s.Hosts[host]; !ok {
-			s.Hosts[host] = []string{name}
-		} else if !com.InSlice(name, s.Hosts[host]) {
-			s.Hosts[host] = append(s.Hosts[host], name)
+		if aliases, ok := s.Hosts.GetOk(host); !ok {
+			s.Hosts.Set(host, &[]string{name})
+			addedHosts++
+		} else if !com.InSlice(name, *aliases) {
+			*aliases = append(*aliases, name)
+			appendsHosts = append(appendsHosts, host)
 		}
 	}
+	s.Hosts.Range(func(host string, aliases *[]string) bool {
+		index := slices.Index(*aliases, name)
+		if index > -1 && !com.InSlice(host, hosts) {
+			*aliases = slices.Delete(*aliases, index, index+1)
+			hasRemoved = true
+		}
+		return true
+	})
+	if hasRemoved {
+		s.Hosts.ClearEmpty(func(_ string, val *[]string) bool {
+			return len(*val) == 0
+		})
+	}
+	if addedHosts > 0 || hasRemoved {
+		s.hostsNum.Store(int32(s.Hosts.Size()))
+	}
 	info := &Info{
 		Protocol: `http`,
 		Name:     name,
@@ -135,7 +159,14 @@ func (s *Subdomains) Add(name string, e *echo.Echo) *Subdomains {
 			}
 		}
 	}
-	s.Alias[name] = info
+	s.Alias.Set(name, info)
+	if len(e.Prefix()) > 0 {
+		for _, host := range appendsHosts {
+			if aliases, ok := s.Hosts.GetOk(host); ok {
+				s.sort(*aliases)
+			}
+		}
+	}
 	return s
 }
 
@@ -144,16 +175,17 @@ func (s *Subdomains) Get(args ...string) *Info {
 	if len(args) > 0 {
 		name = args[0]
 	}
-	if e, ok := s.Alias[name]; ok {
+	if e, ok := s.Alias.GetOk(name); ok {
 		return e
 	}
 	return nil
 }
 
 func (s *Subdomains) SetDebug(on bool) *Subdomains {
-	for _, info := range s.Alias {
+	s.Alias.Range(func(key string, info *Info) bool {
 		info.SetDebug(on)
-	}
+		return true
+	})
 	return s
 }
 
@@ -214,46 +246,48 @@ func (s *Subdomains) RelativeURLByName(name string, params ...interface{}) strin
 
 func (s *Subdomains) sort(names []string) []string {
 	sort.Slice(names, func(i, j int) bool {
-		return len(s.Alias[names[i]].Prefix()) > len(s.Alias[names[j]].Prefix())
+		return len(s.Alias.Get(names[i]).Prefix()) > len(s.Alias.Get(names[j]).Prefix())
 	})
 	return names
 }
 
-func (s *Subdomains) sortHosts() {
-	for k := range s.Hosts {
-		s.Hosts[k] = s.sort(s.Hosts[k])
-	}
+func (s *Subdomains) SortHosts() {
+	s.Hosts.Range(func(key string, val *[]string) bool {
+		s.sort(*val)
+		return true
+	})
 }
 
 func (s *Subdomains) FindByDomain(host string, upath string) (*echo.Echo, bool) {
 	var (
-		names  []string
+		names  *[]string
 		exists bool
 	)
-	if len(s.Hosts) == 1 && len(s.Hosts[``]) > 0 {
-		names = s.Hosts[``]
-		exists = true
-	} else {
-		names, exists = s.Hosts[host]
+	if s.hostsNum.Load() == 1 {
+		names = s.Hosts.Get(``)
+		exists = names != nil && len(*names) > 0
+	}
+	if !exists {
+		names, exists = s.Hosts.GetOk(host)
 		if !exists {
 			if p := strings.LastIndexByte(host, ':'); p > -1 {
-				names, exists = s.Hosts[host[0:p]]
+				names, exists = s.Hosts.GetOk(host[0:p])
 				if !exists {
-					names, exists = s.Hosts[``]
+					names, exists = s.Hosts.GetOk(``)
 				}
 			}
 		}
 	}
 	var info *Info
-	if exists {
-		for _, name := range names {
-			info, exists = s.Alias[name]
+	if exists && names != nil {
+		for _, name := range *names {
+			info, exists = s.Alias.GetOk(name)
 			if exists && (upath == info.Prefix() || strings.HasPrefix(upath, info.Prefix()+`/`)) {
 				return info.Echo, exists
 			}
 		}
 	}
-	info, exists = s.Alias[s.Default]
+	info, exists = s.Alias.GetOk(s.Default)
 	if exists {
 		return info.Echo, exists
 	}
@@ -277,20 +311,22 @@ func (s *Subdomains) Ready() *Info {
 	if s.dispatcher == nil {
 		s.dispatcher = s.DefaultDispatcher
 	}
-	s.sortHosts()
+	s.hostsNum.Store(int32(s.Hosts.Size()))
+	s.SortHosts()
 	e := s.Get(s.Boot)
 	if e == nil {
-		for _, info := range s.Alias {
+		s.Alias.Range(func(key string, info *Info) bool {
 			e = info
-			break
-		}
+			return false
+		})
 	}
-	for _, info := range s.Alias {
+	s.Alias.Range(func(key string, info *Info) bool {
 		if e == info {
-			continue
+			return true
 		}
 		info.Commit()
-	}
+		return true
+	})
 	return e
 }
 
diff --git a/subdomains/subdomains_test.go b/subdomains/subdomains_test.go
index a142d50..7ea8d35 100644
--- a/subdomains/subdomains_test.go
+++ b/subdomains/subdomains_test.go
@@ -4,6 +4,7 @@ import (
 	"net/http"
 	"testing"
 
+	"github.com/admpub/log"
 	"github.com/stretchr/testify/assert"
 	"github.com/webx-top/echo"
 	"github.com/webx-top/echo/engine"
@@ -14,7 +15,9 @@ func request(method, path string, h engine.Handler, reqRewrite ...func(*http.Req
 	rec := test.Request(method, path, h, reqRewrite...)
 	return rec.Code, rec.Body.String()
 }
+
 func TestSortHosts(t *testing.T) {
+	defer log.Close()
 	a := New()
 	e := echo.New()
 	e.Get(`/`, func(c echo.Context) error {
@@ -32,7 +35,8 @@ func TestSortHosts(t *testing.T) {
 	a.Add(`backend`, e2)
 
 	a.Ready().Commit()
-	assert.Equal(t, []string{`backend`, `frontend`}, a.Hosts[``])
+	assert.Equal(t, []string{`backend`, `frontend`}, *a.Hosts.Get(``))
+	assert.Equal(t, int32(1), a.hostsNum.Load())
 
 	c, b := request(echo.GET, "/", a)
 	assert.Equal(t, http.StatusOK, c)
@@ -49,4 +53,25 @@ func TestSortHosts(t *testing.T) {
 	c, b = request(echo.GET, "/adminindex", a)
 	assert.Equal(t, http.StatusNotFound, c)
 	assert.Equal(t, http.StatusText(http.StatusNotFound), b)
+
+	e3 := echo.New()
+	e3.Get(``, func(c echo.Context) error {
+		return c.String(`backend`)
+	})
+	e3.Get(`/index`, func(c echo.Context) error {
+		return c.String(`backend-index`)
+	})
+	a.Add(`backend@github.com,coscms.com`, e3)
+	assert.Equal(t, []string{`frontend`}, *a.Hosts.Get(``))
+	assert.Equal(t, []string{`backend`}, *a.Hosts.Get(`github.com`))
+	assert.Equal(t, []string{`backend`}, *a.Hosts.Get(`coscms.com`))
+	assert.Equal(t, int32(3), a.hostsNum.Load())
+
+	e4 := echo.New()
+	e4.SetPrefix(`/portal`)
+	e4.Get(`/`, func(c echo.Context) error {
+		return c.String(`portal`)
+	})
+	a.Add(`portal`, e4)
+	assert.Equal(t, []string{`portal`, `frontend`}, *a.Hosts.Get(``))
 }