Initial QSfera import

Server/vendor/github.com/jonboulle/clockwork/timer.go

@@ -0,0 +1,79 @@
+package clockwork
+
+import "time"
+
+// Timer provides an interface which can be used instead of directly using
+// [time.Timer]. The real-time timer t provides events through t.C which becomes
+// t.Chan() to make this channel requirement definable in this interface.
+type Timer interface {
+	Chan() <-chan time.Time
+	Reset(d time.Duration) bool
+	Stop() bool
+}
+
+type realTimer struct{ *time.Timer }
+
+func (r realTimer) Chan() <-chan time.Time {
+	return r.C
+}
+
+type fakeTimer struct {
+	// The channel associated with the firer, used to send expiration times.
+	c chan time.Time
+
+	// The time when the firer expires. Only meaningful if the firer is currently
+	// one of a FakeClock's waiters.
+	exp time.Time
+
+	// reset and stop provide the implementation of the respective exported
+	// functions.
+	reset func(d time.Duration) bool
+	stop  func() bool
+
+	// If present when the timer fires, the timer calls afterFunc in its own
+	// goroutine rather than sending the time on Chan().
+	afterFunc func()
+}
+
+func newFakeTimer(fc *FakeClock, afterfunc func()) *fakeTimer {
+	var ft *fakeTimer
+	ft = &fakeTimer{
+		c: make(chan time.Time, 1),
+		reset: func(d time.Duration) bool {
+			fc.l.Lock()
+			defer fc.l.Unlock()
+			// fc.l must be held across the calls to stopExpirer & setExpirer.
+			stopped := fc.stopExpirer(ft)
+			fc.setExpirer(ft, d)
+			return stopped
+		},
+		stop: func() bool { return fc.stop(ft) },
+
+		afterFunc: afterfunc,
+	}
+	return ft
+}
+
+func (f *fakeTimer) Chan() <-chan time.Time { return f.c }
+
+func (f *fakeTimer) Reset(d time.Duration) bool { return f.reset(d) }
+
+func (f *fakeTimer) Stop() bool { return f.stop() }
+
+func (f *fakeTimer) expire(now time.Time) *time.Duration {
+	if f.afterFunc != nil {
+		go f.afterFunc()
+		return nil
+	}
+
+	// Never block on expiration.
+	select {
+	case f.c <- now:
+	default:
+	}
+	return nil
+}
+
+func (f *fakeTimer) expiration() time.Time { return f.exp }
+
+func (f *fakeTimer) setExpiration(t time.Time) { f.exp = t }