可以复现，甚至标准库 http 实现也可以复现。

```

package main

import (
"fmt"
"net/http"
"time"
)

func handler(w http.ResponseWriter, req *http.Request) {
w.Header().Set("Content-Type", "text/plain")

fmt.Println("start")
time.Sleep(10 * time.Second)
fmt.Println("end")
}

func main() {

http.HandleFunc("/", handler)
http.ListenAndServe(":8088", nil)
}


```

同时打开 3 个页面输出：
start
end
start
start
end
start
end
start
end
start
end
end