在 go 例程中更新后未返回更新值

Question

我遇到了一个问题，即返回的整数值与一组相同，即使在 go 子例程中更新了值之后也是如此。我似乎无法弄清楚出了什么问题。

//HostUptimeReporter - struct

type HostUptimeReporter struct {

    updateInterval int

    uptime int

    shutdownSignal chan bool

}

//NewHostUpTimeReporter - create reporter instance

func NewHostUpTimeReporter(updateIntervalInSeconds int) HostUptimeReporter {

    instance := HostUptimeReporter{updateInterval: updateIntervalInSeconds, shutdownSignal: make(chan bool), uptime:59}

    ticker := time.NewTicker(time.Duration(updateIntervalInSeconds) * time.Second)

    go func() {

        for {

            select {

            case <-ticker.C:

                instance.uptime += updateIntervalInSeconds          

                fmt.Printf("updated uptime:%v\n", instance.uptime)

            case <-instance.shutdownSignal:

                ticker.Stop()

                return

            }

        }

    }()

    return instance

}

//Shutdown - shuts down the go routine

func (hupr *HostUptimeReporter) Shutdown(){

    hupr.shutdownSignal <- true

}

func main() {

    hurp := NewHostUpTimeReporter(2)

    defer hurp.Shutdown()

    fmt.Printf("current uptime:%v\n", hurp.uptime)

    time.Sleep(3*time.Second)

    fmt.Printf("new uptime:%v\n", hurp.uptime)

}

https://play.golang.org/p/ODjSBb0YugK

任何指针表示赞赏。

Answer 1

启动 goroutine 的函数返回一个HostUptimeReporter：func NewHostUpTimeReporter(updateIntervalInSeconds int) HostUptimeReporter {像这样返回一个完整的结构会返回该结构的副本，因此 goroutine 和调用NewHostUpTimeReporter者正在查看不同的东西。你想返回一个指针以便他们共享数据：// -----------------------------------------------------vfunc NewHostUpTimeReporter(updateIntervalInSeconds int) *HostUptimeReporter {&nbsp; &nbsp; instance := &HostUptimeReporter{updateInterval: updateIntervalInSeconds, shutdownSignal: make(chan bool), uptime:59}&nbsp; &nbsp; // ---------^&nbsp; &nbsp; ...