优先选择带渠道的案例

Question

我有这个功能，这样里面的方法就可以自动运行了。我的问题是第二种情况sigC仅在 case ticker.C 完成后才有效，这并不理想，因为程序运行时带有标志，因此如果我想更改标志并改变程序的行为，我必须等待代码方法完成运行，这可能需要一些时间。

我的目标是当我按下 Ctrl+C 时，程序会立即完成运行。

func report() error {

    ticker := time.NewTicker(timeConfig)

    sigC := make(chan os.Signal, 1)

    signal.Notify(sigC, syscall.SIGHUP, syscall.SIGINT, syscall.SIGTERM, syscall.SIGQUIT, os.Interrupt)

    for range ticker.C {

        select {

        case <-ticker.C:

            connection = connectionInit()

            tagValues, err := fetchLatestTags()

            if err != nil {

                return err

            }

            if len(tagValues) >= threshold {

                metrics, err := fetchMetrics(tagValues)

                if err != nil {

                    return err

                }

                if stdout {

                    err = locally(metrics)

                    if err != nil {

                        return err

                    }

                } else {

                    err = sendMail(metrics)

                    if err != nil {

                        return err

                    }

                }

            }

            connection.Close()

        case <-sigC:

            return nil

        }

    }

    return nil

}

Answer 1

如果我理解正确的话，你想要做的是用无限循环替换 range-over-channel 循环。即for range ticker.C { ... }-> for { ... }。如果您希望程序而不是report函数立即完成而不等待case <-ticker.C:块中的代码完成，您应该在单独的 goroutine 中执行该代码块并将case <-sigC:块从更新return nil为os.Exit(1).func report() {&nbsp; &nbsp; ticker := time.NewTicker(timeConfig)&nbsp; &nbsp; defer ticker.Stop()&nbsp; &nbsp; sigC := make(chan os.Signal, 1)&nbsp; &nbsp; signal.Notify(sigC, syscall.SIGHUP, syscall.SIGINT, syscall.SIGTERM, syscall.SIGQUIT, os.Interrupt)&nbsp; &nbsp; for {&nbsp; &nbsp; &nbsp; &nbsp; select {&nbsp; &nbsp; &nbsp; &nbsp; case <-ticker.C:&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; go func() {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; connection = connectionInit()&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; tagValues, err := fetchLatestTags()&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; if err != nil {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; if len(tagValues) >= threshold {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; metrics, err := fetchMetrics(tagValues)&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; if err != nil {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; if stdout {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; err = locally(metrics)&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; if err != nil {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; } else {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; err = sendMail(metrics)&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; if err != nil {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; connection.Close()&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }()&nbsp; &nbsp; &nbsp; &nbsp; case <-sigC:&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; os.Exit(1)&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; }}