kubernetes/staging/src/k8s.io/apimachinery/pkg/util/wait/delay.go

type DelayFunc …

// Timer takes an arbitrary delay function and returns a timer that can handle arbitrary interval changes.
// Use Backoff{...}.Timer() for simple delays and more efficient timers.
func (fn DelayFunc) Timer(c clock.Clock) Timer { … }

// Until takes an arbitrary delay function and runs until cancelled or the condition indicates exit. This
// offers all of the functionality of the methods in this package.
func (fn DelayFunc) Until(ctx context.Context, immediate, sliding bool, condition ConditionWithContextFunc) error { … }

// Concurrent returns a version of this DelayFunc that is safe for use by multiple goroutines that
// wish to share a single delay timer.
func (fn DelayFunc) Concurrent() DelayFunc { … }