package timer import ( "time" tmsync "github.com/tendermint/tendermint/libs/sync" ) /* ThrottleTimer fires an event at most "dur" after each .Set() call. If a short burst of .Set() calls happens, ThrottleTimer fires once. If a long continuous burst of .Set() calls happens, ThrottleTimer fires at most once every "dur". */ type ThrottleTimer struct { Name string Ch chan struct{} quit chan struct{} dur time.Duration mtx tmsync.Mutex timer *time.Timer isSet bool } func NewThrottleTimer(name string, dur time.Duration) *ThrottleTimer { var ch = make(chan struct{}) var quit = make(chan struct{}) var t = &ThrottleTimer{Name: name, Ch: ch, dur: dur, quit: quit} t.mtx.Lock() t.timer = time.AfterFunc(dur, t.fireRoutine) t.mtx.Unlock() t.timer.Stop() return t } func (t *ThrottleTimer) fireRoutine() { t.mtx.Lock() defer t.mtx.Unlock() select { case t.Ch <- struct{}{}: t.isSet = false case <-t.quit: // do nothing default: t.timer.Reset(t.dur) } } func (t *ThrottleTimer) Set() { t.mtx.Lock() defer t.mtx.Unlock() if !t.isSet { t.isSet = true t.timer.Reset(t.dur) } } func (t *ThrottleTimer) Unset() { t.mtx.Lock() defer t.mtx.Unlock() t.isSet = false t.timer.Stop() } // For ease of .Stop()'ing services before .Start()'ing them, // we ignore .Stop()'s on nil ThrottleTimers func (t *ThrottleTimer) Stop() bool { if t == nil { return false } close(t.quit) t.mtx.Lock() defer t.mtx.Unlock() return t.timer.Stop() }