Add Kmutex

common/kmutex/mutex.go

@@ -0,0 +1,57 @@
+package kmutex
+
+import "sync"
+
+type Kmutex[T comparable] struct {
+	l sync.Locker
+	s map[T]*klock
+}
+
+type klock struct {
+	cond *sync.Cond
+	ref  uint64
+}
+
+// Create new Kmutex
+func New[T comparable]() *Kmutex[T] {
+	l := sync.Mutex{}
+	return &Kmutex[T]{
+		l: &l,
+		s: make(map[T]*klock),
+	}
+}
+
+// Unlock Kmutex by unique ID
+func (km *Kmutex[T]) Unlock(key T) {
+	km.l.Lock()
+	defer km.l.Unlock()
+	kl, ok := km.s[key]
+	if !ok || kl.ref == 0 {
+		panic("unlock of unlocked kmutex")
+	}
+	kl.ref--
+	if kl.ref == 0 {
+		delete(km.s, key)
+		return
+	}
+	kl.cond.Signal()
+}
+
+// Lock Kmutex by unique ID
+func (km *Kmutex[T]) Lock(key T) {
+	km.l.Lock()
+	defer km.l.Unlock()
+	for {
+		kl, ok := km.s[key]
+		if !ok {
+			km.s[key] = &klock{
+				cond: sync.NewCond(km.l),
+				ref:  1,
+			}
+			return
+		}
+		kl.ref++
+		kl.cond.Wait()
+		return
+	}
+}