init: 1.0.0

pkg/syncx/onceguard.go

@@ -0,0 +1,18 @@
+package syncx
+
+import "sync/atomic"
+
+// An OnceGuard is used to make sure a resource can be taken once.
+type OnceGuard struct {
+	done uint32
+}
+
+// Taken checks if the resource is taken.
+func (og *OnceGuard) Taken() bool {
+	return atomic.LoadUint32(&og.done) == 1
+}
+
+// Take takes the resource, returns true on success, false for otherwise.
+func (og *OnceGuard) Take() bool {
+	return atomic.CompareAndSwapUint32(&og.done, 0, 1)
+}