Golang中处理高延迟IO操作的策略

func handleIO(data interface{}, resultChan chan<- interface{}) {
    // 模拟高延迟IO操作
    time.Sleep(time.Second * 5)
    // 处理IO结果
    result := processData(data)
    // 将结果发送到channel
    resultChan <- result
}

func main() {
    dataList := []interface{}{"data1", "data2", "data3"}
    resultChan := make(chan interface{}, len(dataList))

    for _, data := range dataList {
        go handleIO(data, resultChan)
    }

    // 等待所有goroutine完成
    for i := 0; i < len(dataList); i++ {
        result := <-resultChan
        fmt.Println("Result:", result)
    }
}

func processData(data interface{}) interface{} {
    // 模拟数据处理
    return fmt.Sprintf("Processed: %v", data)
}

func fetchData(url string, dataChan chan<- string, errChan chan<- error) {
    resp, err := http.Get(url)
    if err != nil {
        errChan <- err
        return
    }
    defer resp.Body.Close()

    body, err := ioutil.ReadAll(resp.Body)
    if err != nil {
        errChan <- err
        return
    }

    dataChan <- string(body)
}

func main() {
    urls := []string{"https://example.com", "https://google.com", "https://github.com"}
    dataChan := make(chan string)
    errChan := make(chan error)

    for _, url := range urls {
        go fetchData(url, dataChan, errChan)
    }

    for i := 0; i < len(urls); i++ {
        select {
        case data := <-dataChan:
            fmt.Println("Data:", data[:100], "...") // 打印前100个字符
        case err := <-errChan:
            fmt.Println("Error:", err)
        case <-time.After(time.Second * 10): // 超时处理
            fmt.Println("Timeout")
        }
    }
}

func doSomething(ctx context.Context, data interface{}, resultChan chan<- interface{}) {
    select {
    case <-ctx.Done():
        fmt.Println("Cancelled")
        return
    case <-time.After(time.Second * 5): // 模拟耗时操作
        result := processData(data)
        resultChan <- result
    }
}

func main() {
    ctx, cancel := context.WithTimeout(context.Background(), time.Second*3)
    defer cancel()

    data := "some data"
    resultChan := make(chan interface{}, 1)

    go doSomething(ctx, data, resultChan)

    select {
    case result := <-resultChan:
        fmt.Println("Result:", result)
    case <-ctx.Done():
        fmt.Println("Context cancelled:", ctx.Err())
    }
}

func processData(data interface{}) interface{} {
    return fmt.Sprintf("Processed: %v", data)
}

func worker(id int, jobs <-chan int, results chan<- int, wg *sync.WaitGroup) {
    defer wg.Done() // 标记当前goroutine完成

    for j := range jobs {
        fmt.Println("worker", id, "processing job", j)
        time.Sleep(time.Second)
        results <- j * 2
    }
}

func main() {
    jobs := make(chan int, 100)
    results := make(chan int, 100)

    var wg sync.WaitGroup

    for w := 1; w <= 3; w++ {
        wg.Add(1) // 增加一个等待的goroutine
        go worker(w, jobs, results, &wg)
    }

    for j := 1; j <= 9; j++ {
        jobs <- j
    }
    close(jobs) // 关闭jobs channel，worker goroutine会退出

    wg.Wait()   // 等待所有worker goroutine完成
    close(results)

    for a := range results {
        fmt.Println(a)
    }
}

# 收集trace信息
go tool trace -http=:8080 your_program

# 然后在浏览器中访问 http://localhost:8080 查看trace报告