Initial publication of ZFSSA CSI driver

pkg/utils/sync.go

@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2021, Oracle and/or its affiliates.
+ * Licensed under the Universal Permissive License v 1.0 as shown at https://oss.oracle.com/licenses/upl/
+ */
+
+package utils
+
+import (
+	"context"
+	"sync"
+)
+
+type Bolt struct {
+	mutex	sync.Mutex
+	cv		*sync.Cond
+	context	context.Context
+}
+
+func NewBolt() *Bolt {
+	bolt := new(Bolt)
+	bolt.cv = sync.NewCond(&bolt.mutex)
+	return bolt
+}
+
+func (l *Bolt) Lock(ctx context.Context) {
+	l.mutex.Lock()
+	for l.context != nil {
+		l.cv.Wait()
+	}
+	l.context = ctx
+	l.mutex.Unlock()
+}
+
+func (l *Bolt) Unlock(ctx context.Context) {
+	l.mutex.Lock()
+	if l.context != ctx {
+		panic("wrong owner unlocking fs")
+	}
+	l.context = nil
+	l.cv.Signal()
+	l.mutex.Unlock()
+}