Vendor temporarily

vendor/github.com/mitchellh/cli/ui_concurrent.go

@@ -0,0 +1,54 @@
+package cli
+
+import (
+	"sync"
+)
+
+// ConcurrentUi is a wrapper around a Ui interface (and implements that
+// interface) making the underlying Ui concurrency safe.
+type ConcurrentUi struct {
+	Ui Ui
+	l  sync.Mutex
+}
+
+func (u *ConcurrentUi) Ask(query string) (string, error) {
+	u.l.Lock()
+	defer u.l.Unlock()
+
+	return u.Ui.Ask(query)
+}
+
+func (u *ConcurrentUi) AskSecret(query string) (string, error) {
+	u.l.Lock()
+	defer u.l.Unlock()
+
+	return u.Ui.AskSecret(query)
+}
+
+func (u *ConcurrentUi) Error(message string) {
+	u.l.Lock()
+	defer u.l.Unlock()
+
+	u.Ui.Error(message)
+}
+
+func (u *ConcurrentUi) Info(message string) {
+	u.l.Lock()
+	defer u.l.Unlock()
+
+	u.Ui.Info(message)
+}
+
+func (u *ConcurrentUi) Output(message string) {
+	u.l.Lock()
+	defer u.l.Unlock()
+
+	u.Ui.Output(message)
+}
+
+func (u *ConcurrentUi) Warn(message string) {
+	u.l.Lock()
+	defer u.l.Unlock()
+
+	u.Ui.Warn(message)
+}