go语言中空结构体的实现

type Lamp struct{}

func (l Lamp) On() {
        println("On")

}
func (l Lamp) Off() {
        println("Off")
}

type Lamp struct{}

func main() {
    lamp := Lamp{}
    fmt.Print(unsafe.Sizeof(lamp))
}
// output: 0

func main() {
    ch := make(chan struct{}, 1)
    go func() {
        <-ch
        // do something
    }()
    ch <- struct{}{}
    // ...
}

package main

import (
    "fmt"
    "time"
)

func worker(id int, done chan struct{}) {
    for {
        select {
        case <-done:
            fmt.Printf("Worker %d shutting down\n", id)
            return
        default:
            fmt.Printf("Worker %d working\n", id)
            time.Sleep(500 * time.Millisecond)
        }
    }
}

func main() {
    done := make(chan struct{})
    numWorkers := 3

    // 启动多个工作协程
    for i := 1; i <= numWorkers; i++ {
        go worker(i, done)
    }

    // 模拟一些工作
    time.Sleep(2 * time.Second)

    // 发送关闭信号
    close(done)

    // 等待一段时间以确保所有工作协程都已退出
    time.Sleep(1 * time.Second)
}

package main

import (
    "fmt"
    "sync"
)

func task(id int, wg *sync.WaitGroup, done chan struct{}) {
    defer wg.Done()
    fmt.Printf("Task %d completed\n", id)
    done <- struct{}{} // 发送一个空结构体表示任务完成
}

func main() {
    var wg sync.WaitGroup
    done := make(chan struct{}, 3) // 缓冲区大小为任务数量

    for i := 1; i <= 3; i++ {
        wg.Add(1)
        go task(i, &wg, done)
    }

    // 等待所有任务完成
    go func() {
        wg.Wait()
        close(done)
    }()

    // 接收所有完成信号
    for range done {
        fmt.Println("Received completion signal")
    }

    fmt.Println("All tasks completed")
}