func doTask(id int) {
    time.Sleep(1 * time.Second) // 模拟耗时操作
    fmt.Printf("任务 %d 完成\n", id)
}
<p>func main() {
for i := 0; i < 5; i++ {
go doTask(i)
}
time.Sleep(2 * time.Second) // 等待所有任务完成
}</p>

func worker(id int, jobs <-chan int, results chan<- int) {
    for job := range jobs {
        fmt.Printf("Worker %d 正在处理任务 %d\n", id, job)
        time.Sleep(500 * time.Millisecond)
        results <- job * 2
    }
}
<p>func main() {
jobs := make(chan int, 10)
results := make(chan int, 10)</p><pre class='brush:php;toolbar:false;'>// 启动 3 个 worker
for w := 1; w <= 3; w++ {
    go worker(w, jobs, results)
}

// 发送 5 个任务
for j := 1; j <= 5; j++ {
    jobs <- j
}
close(jobs)

// 收集结果
for i := 0; i < 5; i++ {
    result := <-results
    fmt.Printf("得到结果: %d\n", result)
}

}

func processItem(item int, wg *sync.WaitGroup) {
    defer wg.Done()
    time.Sleep(300 * time.Millisecond)
    fmt.Printf("处理完成: %d\n", item)
}
<p>func main() {
var wg sync.WaitGroup
items := []int{1, 2, 3, 4, 5}</p><pre class='brush:php;toolbar:false;'>for _, item := range items {
    wg.Add(1)
    go processItem(item, &wg)
}

wg.Wait() // 等待所有任务结束
fmt.Println("所有任务已完成")

}

func limitedParallel(tasks []func(), maxConcurrency int) {
    sem := make(chan struct{}, maxConcurrency)
    var wg sync.WaitGroup
<pre class='brush:php;toolbar:false;'>for _, task := range tasks {
    wg.Add(1)
    go func(t func()) {
        defer wg.Done()
        sem <- struct{}{} // 获取令牌
        t()
        <-sem // 释放令牌
    }(task)
}

wg.Wait()

}