tendermint/common/repeat_timer.go

157 lines
3.0 KiB
Go

package common
import (
"sync"
"time"
)
// Ticker is a basic ticker interface.
type Ticker interface {
Chan() <-chan time.Time
Stop()
Reset()
}
// DefaultTicker wraps the stdlibs Ticker implementation.
type DefaultTicker struct {
t *time.Ticker
dur time.Duration
}
// NewDefaultTicker returns a new DefaultTicker
func NewDefaultTicker(dur time.Duration) *DefaultTicker {
return &DefaultTicker{
time.NewTicker(dur),
dur,
}
}
// Implements Ticker
func (t *DefaultTicker) Chan() <-chan time.Time {
return t.t.C
}
// Implements Ticker
func (t *DefaultTicker) Stop() {
t.t.Stop()
t.t = nil
}
// Implements Ticker
func (t *DefaultTicker) Reset() {
t.t = time.NewTicker(t.dur)
}
// ManualTicker wraps a channel that can be manually sent on
type ManualTicker struct {
ch chan time.Time
}
// NewManualTicker returns a new ManualTicker
func NewManualTicker(ch chan time.Time) *ManualTicker {
return &ManualTicker{
ch: ch,
}
}
// Implements Ticker
func (t *ManualTicker) Chan() <-chan time.Time {
return t.ch
}
// Implements Ticker
func (t *ManualTicker) Stop() {
// noop
}
// Implements Ticker
func (t *ManualTicker) Reset() {
// noop
}
//---------------------------------------------------------------------
/*
RepeatTimer repeatedly sends a struct{}{} to .Ch after each "dur" period.
It's good for keeping connections alive.
A RepeatTimer must be Stop()'d or it will keep a goroutine alive.
*/
type RepeatTimer struct {
Ch chan time.Time
mtx sync.Mutex
name string
ticker Ticker
quit chan struct{}
wg *sync.WaitGroup
}
// NewRepeatTimer returns a RepeatTimer with the DefaultTicker.
func NewRepeatTimer(name string, dur time.Duration) *RepeatTimer {
ticker := NewDefaultTicker(dur)
return NewRepeatTimerWithTicker(name, ticker)
}
// NewRepeatTimerWithTicker returns a RepeatTimer with the given ticker.
func NewRepeatTimerWithTicker(name string, ticker Ticker) *RepeatTimer {
var t = &RepeatTimer{
Ch: make(chan time.Time),
ticker: ticker,
quit: make(chan struct{}),
wg: new(sync.WaitGroup),
name: name,
}
t.wg.Add(1)
go t.fireRoutine(t.ticker.Chan())
return t
}
func (t *RepeatTimer) fireRoutine(ch <-chan time.Time) {
for {
select {
case t_ := <-ch:
t.Ch <- t_
case <-t.quit:
// needed so we know when we can reset t.quit
t.wg.Done()
return
}
}
}
// Wait the duration again before firing.
func (t *RepeatTimer) Reset() {
t.Stop()
t.mtx.Lock() // Lock
defer t.mtx.Unlock()
t.ticker.Reset()
t.quit = make(chan struct{})
t.wg.Add(1)
go t.fireRoutine(t.ticker.Chan())
}
// For ease of .Stop()'ing services before .Start()'ing them,
// we ignore .Stop()'s on nil RepeatTimers.
func (t *RepeatTimer) Stop() bool {
if t == nil {
return false
}
t.mtx.Lock() // Lock
defer t.mtx.Unlock()
exists := t.ticker != nil
if exists {
t.ticker.Stop() // does not close the channel
select {
case <-t.Ch:
// read off channel if there's anything there
default:
}
close(t.quit)
t.wg.Wait() // must wait for quit to close else we race Reset
}
return exists
}