我有以下代碼：//main.gopackage mainimport ( "edriven/events" "fmt" "math" "time")func main() { fmt.Println("Starting") events.Wg.Add(1) go events.User.Trigger("new", "Hasan") events.Wg.Add(1) go events.User.Trigger("name", []any{"Hasan", "Ali"}) events.Wg.Add(1) go events.User.Trigger("new", "Ali") //for x := range <-events.Publish { // fmt.Println(x) //} for { select { case x := <-events.Publish: fmt.Println(x) default: fmt.Println("waiting for data ...") time.Sleep((time.Duration(math.MaxInt64))) } }}和//events/user.gopackage eventsimport "fmt"var User Eventsfunc init() { User.register("new", func(payload ...any) { fmt.Println(payload[0]) //message := make(map[string]string) //message["new"] = "done new" Publish <- "{'new':'done'}" Wg.Done() }) User.register("name", func(payload ...any) { for index, person := range payload { fmt.Println(person, index) } //message := make(map[string]string) //message["name"] = "done name" Publish <- "{'name':'done'}" //message Wg.Done() })}和//events/setup.gopackage eventsimport "sync"var Wg sync.WaitGroupvar Publish chan stringtype Event struct { Name string Action func(...any) // <-chan string // func(...any) ([]any, error)}type Events struct { handlers []Event}func (e *Events) register(name string, action func(...any)) { e.handlers = append(e.handlers, Event{ Name: name, Action: action, })}func (e *Events) Trigger(name string, payload ...any) { for _, event := range e.handlers { if event.Name == name { event.Action(payload) } }}我得到的輸出如下，沒有通過通道交換任何東西
1 回答
九州編程
TA貢獻(xiàn)1785條經(jīng)驗(yàn) 獲得超4個(gè)贊
這段代碼有問題
for {
select {
case x := <- events.Publish:
fmt.Println(x)
default:
fmt.Println("waiting for data ...")
time.Sleep((time.Duration(math.MaxInt64)))
}
}
當(dāng)select被調(diào)用并假設(shè)Publish通道仍然為空時(shí)，默認(rèn)情況將運(yùn)行并使用該time.Sleep語(yǔ)句永遠(yuǎn)阻塞主循環(huán)。因此，即使Publish通道從另一個(gè) go-routine 接收數(shù)據(jù)，主 go-routine 仍然停留在該 Sleep 語(yǔ)句上。
任何時(shí)候你想將定時(shí)等待與通道事件結(jié)合起來(lái)，你可以這樣做：
timerChannel := time.NewTimer(duration)
select {
case <-timerChannel.C:
{
// time out
}
case x := <-events.Publish:
{
fmt.println(x)
}
}
但是由于您的意圖似乎只是阻止main退出，所以它更簡(jiǎn)單：
for {
x := <- events.Publish: // blocks until Publish channel has data
fmt.Println(x)
}
但是正如你所說的那樣，這會(huì)導(dǎo)致僵局，因?yàn)樵谀愕娜齻€(gè) go-routines 退出后，就沒有什么可做的了。
快速解決：
func main() {
fmt.Println("Starting")
events.Wg.Add(1)
go events.User.Trigger("new", "Hasan")
events.Wg.Add(1)
go events.User.Trigger("name", []any{"Hasan", "Ali"})
events.Wg.Add(1)
go events.User.Trigger("new", "Ali")
exitChannel := make(chan bool)
go func() {
events.Wg.Wait()
close(exitChannel)
}()
canExit := false
for !canExit {
select {
case x := <-events.Publish:
{
fmt.Println(x)
}
case <- exitChannel:
{
canExit = true
}
}
}
}
正如評(píng)論中所討論的，需要初始化通道，缺少make，必須按以下方式完成：
package events
import "sync"
var (
Wg sync.WaitGroup
Publish chan string
)
func init() {
Publish = make(chan string)
}
- 1 回答
- 0 關(guān)注
- 130 瀏覽
添加回答
舉報(bào)
0/150
提交
取消