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package v2
import (
"fmt"
"sync/atomic"
"github.com/tendermint/tendermint/libs/log"
)
// TODO
// * revisit panic conditions
// * audit log levels
// * Convert routine to an interface with concrete implmentation
type handleFunc = func(event Event) (Events, error)
type Routine struct {
name string
input chan Event
errors chan error
out chan Event
stopped chan struct{}
rdy chan struct{}
fin chan error
running *uint32
handle handleFunc
logger log.Logger
metrics *Metrics
stopping *uint32
}
func newRoutine(name string, handleFunc handleFunc) *Routine {
return &Routine{
name: name,
input: make(chan Event, 1),
handle: handleFunc,
errors: make(chan error, 1),
out: make(chan Event, 1),
stopped: make(chan struct{}, 1),
rdy: make(chan struct{}, 1),
fin: make(chan error, 1),
running: new(uint32),
stopping: new(uint32),
logger: log.NewNopLogger(),
metrics: NopMetrics(),
}
}
func (rt *Routine) setLogger(logger log.Logger) {
rt.logger = logger
}
func (rt *Routine) setMetrics(metrics *Metrics) {
rt.metrics = metrics
}
func (rt *Routine) start() {
rt.logger.Info(fmt.Sprintf("%s: run\n", rt.name))
starting := atomic.CompareAndSwapUint32(rt.running, uint32(0), uint32(1))
if !starting {
panic("Routine has already started")
}
rt.rdy <- struct{}{}
errorsDrained := false
for {
if !rt.isRunning() {
rt.logger.Info(fmt.Sprintf("%s: breaking because not running\n", rt.name))
break
}
select {
case iEvent, ok := <-rt.input:
rt.metrics.EventsIn.With("routine", rt.name).Add(1)
if !ok {
if !errorsDrained {
rt.logger.Info(fmt.Sprintf("%s: waiting for errors to drain\n", rt.name))
continue // wait for errors to be drainned
}
rt.logger.Info(fmt.Sprintf("%s: stopping\n", rt.name))
rt.stopped <- struct{}{}
rt.terminate(fmt.Errorf("stopped"))
return
}
oEvents, err := rt.handle(iEvent)
rt.metrics.EventsHandled.With("routine", rt.name).Add(1)
if err != nil {
rt.terminate(err)
return
}
rt.metrics.EventsOut.With("routine", rt.name).Add(float64(len(oEvents)))
rt.logger.Info(fmt.Sprintf("%s handled %d events\n", rt.name, len(oEvents)))
for _, event := range oEvents {
rt.logger.Info(fmt.Sprintln("writting back to output"))
rt.out <- event
}
case iEvent, ok := <-rt.errors:
rt.metrics.ErrorsIn.With("routine", rt.name).Add(1)
if !ok {
rt.logger.Info(fmt.Sprintf("%s: errors closed\n", rt.name))
errorsDrained = true
continue
}
oEvents, err := rt.handle(iEvent)
rt.metrics.ErrorsHandled.With("routine", rt.name).Add(1)
if err != nil {
rt.terminate(err)
return
}
rt.metrics.ErrorsOut.With("routine", rt.name).Add(float64(len(oEvents)))
for _, event := range oEvents {
rt.out <- event
}
}
}
}
func (rt *Routine) feedback() {
for event := range rt.out {
rt.trySend(event)
}
}
func (rt *Routine) trySend(event Event) bool {
if !rt.isRunning() || rt.isStopping() {
return false
}
rt.logger.Info(fmt.Sprintf("%s: sending %+v", rt.name, event))
if err, ok := event.(error); ok {
select {
case rt.errors <- err:
rt.metrics.ErrorsSent.With("routine", rt.name).Add(1)
return true
default:
rt.metrics.ErrorsShed.With("routine", rt.name).Add(1)
rt.logger.Info(fmt.Sprintf("%s: errors channel was full\n", rt.name))
return false
}
} else {
select {
case rt.input <- event:
rt.metrics.EventsSent.With("routine", rt.name).Add(1)
return true
default:
rt.metrics.EventsShed.With("routine", rt.name).Add(1)
rt.logger.Info(fmt.Sprintf("%s: channel was full\n", rt.name))
return false
}
}
}
func (rt *Routine) isRunning() bool {
return atomic.LoadUint32(rt.running) == 1
}
func (rt *Routine) isStopping() bool {
return atomic.LoadUint32(rt.stopping) == 1
}
func (rt *Routine) ready() chan struct{} {
return rt.rdy
}
func (rt *Routine) next() chan Event {
return rt.out
}
func (rt *Routine) stop() {
if !rt.isRunning() {
return
}
rt.logger.Info(fmt.Sprintf("%s: stop\n", rt.name))
stopping := atomic.CompareAndSwapUint32(rt.stopping, uint32(0), uint32(1))
if !stopping {
panic("Routine has already stopped")
}
close(rt.input)
close(rt.errors)
<-rt.stopped
}
func (rt *Routine) final() chan error {
return rt.fin
}
func (rt *Routine) terminate(reason error) {
stopped := atomic.CompareAndSwapUint32(rt.running, uint32(1), uint32(0))
if !stopped {
panic("called stop but already stopped")
}
rt.fin <- reason
}