Merge pull request #56 from fjl/feature/raceless-eventer

Fix Eventer race
This commit is contained in:
Jeffrey Wilcke 2014-10-10 16:57:50 +02:00
commit 6fec5bd32e
2 changed files with 60 additions and 9 deletions

View File

@ -1,5 +1,7 @@
package eventer
import "sync"
// Basic receiver interface.
type Receiver interface {
Send(Event)
@ -27,17 +29,18 @@ type Event struct {
type Channels map[string][]Receiver
type EventMachine struct {
mu sync.RWMutex
channels Channels
}
func New() *EventMachine {
return &EventMachine{
channels: make(Channels),
}
return &EventMachine{channels: make(Channels)}
}
func (self *EventMachine) add(typ string, r Receiver) {
self.mu.Lock()
self.channels[typ] = append(self.channels[typ], r)
self.mu.Unlock()
}
// Generalised methods for the known receiver types
@ -64,11 +67,11 @@ func (self *EventMachine) RegisterFunc(typ string, f Function) {
func (self *EventMachine) Register(typ string) Channel {
c := make(Channel, 1)
self.add(typ, c)
return c
}
func (self *EventMachine) Post(typ string, data interface{}) {
self.mu.RLock()
if self.channels[typ] != nil {
ev := Event{typ, data}
for _, receiver := range self.channels[typ] {
@ -76,4 +79,5 @@ func (self *EventMachine) Post(typ string, data interface{}) {
receiver.Send(ev)
}
}
self.mu.RUnlock()
}

View File

@ -1,9 +1,13 @@
package eventer
import "testing"
import (
"math/rand"
"testing"
"time"
)
func TestChannel(t *testing.T) {
eventer := New(nil)
eventer := New()
c := make(Channel, 1)
eventer.RegisterChannel("test", c)
@ -17,7 +21,7 @@ func TestChannel(t *testing.T) {
}
func TestFunction(t *testing.T) {
eventer := New(nil)
eventer := New()
var data string
eventer.RegisterFunc("test", func(ev Event) {
@ -31,7 +35,7 @@ func TestFunction(t *testing.T) {
}
func TestRegister(t *testing.T) {
eventer := New(nil)
eventer := New()
c := eventer.Register("test")
eventer.Post("test", "hello world")
@ -44,7 +48,7 @@ func TestRegister(t *testing.T) {
}
func TestOn(t *testing.T) {
eventer := New(nil)
eventer := New()
c := make(Channel, 1)
eventer.On("test", c)
@ -64,3 +68,46 @@ func TestOn(t *testing.T) {
t.Error("Expected function event with data 'hello world'. Got", data)
}
}
func TestConcurrentUsage(t *testing.T) {
rand.Seed(time.Now().Unix())
eventer := New()
stop := make(chan struct{})
recv := make(chan int)
poster := func() {
for {
select {
case <-stop:
return
default:
eventer.Post("test", "hi")
}
}
}
listener := func(i int) {
time.Sleep(time.Duration(rand.Intn(99)) * time.Millisecond)
c := eventer.Register("test")
// wait for the first event
<-c
recv <- i
// keep receiving to prevent deadlock
for {
select {
case <-stop:
return
case <-c:
}
}
}
nlisteners := 200
go poster()
for i := 0; i < nlisteners; i++ {
go listener(i)
}
// wait until everyone has been served
for i := 0; i < nlisteners; i++ {
<-recv
}
close(stop)
}