global: begin modularization

device/misc.go

@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2019 WireGuard LLC. All Rights Reserved.
+ */
+
+package device
+
+import (
+	"sync/atomic"
+)
+
+/* Atomic Boolean */
+
+const (
+	AtomicFalse = int32(iota)
+	AtomicTrue
+)
+
+type AtomicBool struct {
+	int32
+}
+
+func (a *AtomicBool) Get() bool {
+	return atomic.LoadInt32(&a.int32) == AtomicTrue
+}
+
+func (a *AtomicBool) Swap(val bool) bool {
+	flag := AtomicFalse
+	if val {
+		flag = AtomicTrue
+	}
+	return atomic.SwapInt32(&a.int32, flag) == AtomicTrue
+}
+
+func (a *AtomicBool) Set(val bool) {
+	flag := AtomicFalse
+	if val {
+		flag = AtomicTrue
+	}
+	atomic.StoreInt32(&a.int32, flag)
+}
+
+func min(a, b uint) uint {
+	if a > b {
+		return b
+	}
+	return a
+}