Golang——time.Ticker定时器

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Herio 2022-10-22 01:15:21 ©著作权

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Golang——time.Ticker定时器

ticker一般用来作为时间周期执行命令：

func main() {
    ticker := time.NewTicker(time.Second) // 每隔1s进行一次打印
    for {
        <-ticker.C
        fmt.Println("这是ticker的打印")
    }
}

Ticker结构体

// A Ticker holds a channel that delivers ``ticks'' of a clock
// at intervals.
type Ticker struct {
    C <-chan Time // The channel on which the ticks are delivered.
    r runtimeTimer
}

Ticker保管一个通道，并每隔一段时间向其传递"tick"。

创建时钟周期

time.NewTicker()

func NewTicker(d Duration) *Ticker
NewTicker返回一个新的Ticker，该Ticker包含一个通道字段，并会每隔时间段d就向该通道发送当时的时间。它会调整时间间隔或者丢弃tick信息以适应反应慢的接收者。如果d<=0会panic。关闭该Ticker可以释放相关资源

实例1：在11点35分打印"Golang"

func main() {
    myTicker:=time.NewTicker(time.Second)        //设置时间周期
    for{
        nowTime:=<-myTicker.C        //当前时间
        if nowTime.Hour()==11 && nowTime.Minute()==35{
            fmt.Println("Golang")
            break
        }
    }
}

实例2：每秒打印时间，然后10秒后结束。

package main

import (
    "fmt"
    "time"
)

func main() {
    ticker := time.NewTicker(time.Second)
    defer ticker.Stop()
    done := make(chan bool)
    go func() {
        time.Sleep(10 * time.Second)
        done <- true
    }()
    for {
        select {
        case <-done:
            fmt.Println("Done!")
            return
        case t := <-ticker.C:
            fmt.Println("Current time: ", t)
        }
    }
}

输出结果

Current time:  2022-10-21 09:52:47.7603062 +0800 CST m=+1.029829101
Current time:  2022-10-21 09:52:48.7591099 +0800 CST m=+2.028632801
Current time:  2022-10-21 09:52:49.7620993 +0800 CST m=+3.031622201
Current time:  2022-10-21 09:52:50.7534455 +0800 CST m=+4.022968401
Current time:  2022-10-21 09:52:51.7596767 +0800 CST m=+5.029199601
Current time:  2022-10-21 09:52:52.7634561 +0800 CST m=+6.032979001
Current time:  2022-10-21 09:52:53.7499603 +0800 CST m=+7.019483201
Current time:  2022-10-21 09:52:54.7570725 +0800 CST m=+8.026595401
Current time:  2022-10-21 09:52:55.7489688 +0800 CST m=+9.018491701
Done!

使用Tick()方法

// Tick is a convenience wrapper for NewTicker providing access to the ticking
// channel only. While Tick is useful for clients that have no need to shut down
// the Ticker, be aware that without a way to shut it down the underlying
// Ticker cannot be recovered by the garbage collector; it "leaks".
// Unlike NewTicker, Tick will return nil if d <= 0.
func Tick(d Duration) <-chan Time {
    if d <= 0 {
        return nil
    }
    return NewTicker(d).C
}

实例

// 60秒定期更新一次
    tick := time.Tick(60 * time.Second)
    go func() {
        for {
            <-tick
            err  = do_something(...)
            if err != nil {
                panic(err)
            }
        }
    }()