添加 github.com/pion/dtls 代码

dtls-2.0.9/internal/closer/closer.go

@@ -0,0 +1,45 @@
+// Package closer provides signaling channel for shutdown
+package closer
+
+import (
+	"context"
+)
+
+// Closer allows for each signaling a channel for shutdown
+type Closer struct {
+	ctx       context.Context
+	closeFunc func()
+}
+
+// NewCloser creates a new instance of Closer
+func NewCloser() *Closer {
+	ctx, closeFunc := context.WithCancel(context.Background())
+	return &Closer{
+		ctx:       ctx,
+		closeFunc: closeFunc,
+	}
+}
+
+// NewCloserWithParent creates a new instance of Closer with a parent context
+func NewCloserWithParent(ctx context.Context) *Closer {
+	ctx, closeFunc := context.WithCancel(ctx)
+	return &Closer{
+		ctx:       ctx,
+		closeFunc: closeFunc,
+	}
+}
+
+// Done returns a channel signaling when it is done
+func (c *Closer) Done() <-chan struct{} {
+	return c.ctx.Done()
+}
+
+// Err returns an error of the context
+func (c *Closer) Err() error {
+	return c.ctx.Err()
+}
+
+// Close sends a signal to trigger the ctx done channel
+func (c *Closer) Close() {
+	c.closeFunc()
+}