Go 1.23中Timer无buffer的实现方式详解

package main

import (
	"fmt"
	"time"
)

func main() {
	// 创建一个 Timer，设置 2 秒后触发
	timer := time.NewTimer(2 * time.Second)

	// 等待 Timer 触发
	<-timer.C
	fmt.Println("Timer expired")

	// 如果你想要停止 Timer，可以使用 Stop() 方法
	// timer.Stop()
}

package main

import (
	"fmt"
	"time"
)

func main() {
	// 使用 time.After 创建一个无缓冲的 Timer
	timerCh := time.After(2 * time.Second)

	// 等待 Timer 触发
	<-timerCh
	fmt.Println("Timer expired")
}

package main

import (
	"fmt"
	"time"
)

type MyTimer struct {
	duration time.Duration
	timer    *time.Timer
	resetCh  chan time.Duration
	stopCh   chan struct{}
}

func NewMyTimer(duration time.Duration) *MyTimer {
	t := &MyTimer{
		duration: duration,
		resetCh:  make(chan time.Duration),
		stopCh:   make(chan struct{}),
	}
	t.timer = time.NewTimer(duration)
	go t.run()
	return t
}

func (t *MyTimer) run() {
	for {
		select {
		case <-t.timer.C:
			fmt.Println("Timer expired")
			return
		case newDuration := <-t.resetCh:
			if !t.timer.Stop() {
				<-t.timer.C
			}
			t.timer.Reset(newDuration)
		case <-t.stopCh:
			if !t.timer.Stop() {
				<-t.timer.C
			}
			return
		}
	}
}

func (t *MyTimer) Reset(duration time.Duration) {
	t.resetCh <- duration
}

func (t *MyTimer) Stop() {
	t.stopCh <- struct{}{}
}

func main() {
	timer := NewMyTimer(2 * time.Second)

	time.Sleep(1 * time.Second)
	timer.Reset(3 * time.Second)

	time.Sleep(2 * time.Second)
	timer.Stop()
	fmt.Println("Timer stopped")
}