diff --git a/sdks/storage/utils.go b/sdks/storage/utils.go
new file mode 100644
index 0000000..39268dd
--- /dev/null
+++ b/sdks/storage/utils.go
@@ -0,0 +1,13 @@
+package cdssdk
+
+import (
+	"strings"
+)
+
+func JoinObjectPath(comps ...string) string {
+	return strings.Join(comps, ObjectPathSeparator)
+}
+
+func SplitObjectPath(pat string) []string {
+	return strings.Split(pat, ObjectPathSeparator)
+}
diff --git a/utils/sync2/token_pool.go b/utils/sync2/token_pool.go
new file mode 100644
index 0000000..3fda84b
--- /dev/null
+++ b/utils/sync2/token_pool.go
@@ -0,0 +1,60 @@
+package sync2
+
+import "sync"
+
+type TokenPool[T any] struct {
+	tokens []T
+	cond   *sync.Cond
+	closed bool
+}
+
+func NewTokenPool[T any]() *TokenPool[T] {
+	return &TokenPool[T]{
+		tokens: make([]T, 0),
+		cond:   sync.NewCond(new(sync.Mutex)),
+	}
+}
+
+func NewTokenPoolWithTokens[T any](tokens ...T) *TokenPool[T] {
+	b := NewTokenPool[T]()
+	b.tokens = append(b.tokens, tokens...)
+	return b
+}
+
+func (b *TokenPool[T]) Take() (T, bool) {
+	b.cond.L.Lock()
+	defer b.cond.L.Unlock()
+	var ret T
+
+	if b.closed {
+		return ret, false
+	}
+
+	if len(b.tokens) == 0 {
+		b.cond.Wait()
+
+		if len(b.tokens) == 0 {
+			return ret, false
+		}
+	}
+
+	ret = b.tokens[0]
+	b.tokens = b.tokens[1:]
+
+	return ret, true
+}
+
+func (b *TokenPool[T]) Put(t T) {
+	b.cond.L.Lock()
+	b.tokens = append(b.tokens, t)
+	b.cond.L.Unlock()
+	b.cond.Signal()
+}
+
+func (b *TokenPool[T]) Close() {
+	b.cond.L.Lock()
+	b.closed = true
+	b.cond.L.Unlock()
+
+	b.cond.Broadcast()
+}