有持续时间的例行公事

Question

这段代码的目的是使用 goroutine 计算我的电脑和 google.com 之间的每个连接时间。但结果似乎错误。为什么时间一直在增加。这是怎么回事？

2013/12/04 16:10:41 www.google.com 597.175072ms

2013/12/04 16:10:41 www.google.com 608.161898ms

2013/12/04 16:10:41 www.google.com 614.527441ms

2013/12/04 16:10:41 www.google.com 620.51907ms

2013/12/04 16:10:41 www.google.com 630.052257ms

2013/12/04 16:10:42 www.google.com 654.539717ms

2013/12/04 16:10:42 www.google.com 659.144724ms

2013/12/04 16:10:42 www.google.com 1.282230659s

2013/12/04 16:10:42 www.google.com 1.353469764s

package main

import (

    "log"

    "net"

    "net/http"

    "time"

    "sync"

)

var wg sync.WaitGroup

func main() {

    url := "http://www.google.com"

    for i := 0; i < 9; i++ {

        wg.Add(1)

        go request(url)

    }

    wg.Wait()

}

func dialTimeout(network, addr string) (net.Conn, error) {

    return net.DialTimeout(network, addr, time.Duration(1*time.Second))

}

func request(url string) {

    var t0, t1 time.Time

    transport := http.Transport{

        Dial: dialTimeout,

    }

    client := http.Client{

        Transport: &transport,

    }

    t0 = time.Now()

    _, err := client.Get(url)

    t1 = time.Now()

    if err != nil {

        log.Println(err)

    }

    log.Println(url +" "+ t1.Sub(t0).String())

    wg.Done()

}