Question

我遇到了一个问题，其中time.Since（）产生0。谁能突然解释为什么会发生这种情况？我正在尝试衡量Web服务器调用的执行时间。

func handle(f http.HandlerFunc) http.HandlerFunc {
    return func(w http.ResponseWriter, r *http.Request) {
        log.Println(r.URL.Path)
        start := time.Now()
        f(w, r)
        elapsed := time.Since(start)
        log.Printf("took %s", elapsed)
    }
}

它产生此输出，有时会给出“ took 0s” 。我在这里想念东西吗？

2019/01/24 23:28:45 /hello
2019/01/24 23:28:45 took 1.9878ms
2019/01/24 23:28:45 /hello
2019/01/24 23:28:45 took 998.6µs
2019/01/24 23:28:46 /hello
2019/01/24 23:28:46 took 1.0007ms
2019/01/24 23:28:46 /hello
2019/01/24 23:28:46 took 0s
2019/01/24 23:28:46 /hello
2019/01/24 23:28:46 took 0s
2019/01/24 23:28:46 /hello
2019/01/24 23:28:46 took 998.8µs
2019/01/24 23:28:47 /hello
2019/01/24 23:28:47 took 0s
2019/01/24 23:28:47 /hello
2019/01/24 23:28:47 took 0s

Answer 1

我用一个简单的函数复制了您的场景，该函数的执行时间为微秒 (µs)。

package main

import (
    "fmt"
    "math/rand"
    "time"
)

func main() {
    fmt.Println("Start")

    for i := 0; i < 10; i++ {
        start := time.Now()

        var i = rand.Float64() * 100

        time.Sleep(time.Duration(i) * time.Microsecond)

        elapsed := time.Since(start)
        fmt.Printf("took %s", elapsed)
        fmt.Println()

    }

}

但是我没有得到 0s

输出：

Start
took 60µs
took 94µs
took 66µs
took 43µs
took 42µs
took 68µs
took 6µs
took 15µs
took 9µs
took 30µs

time.Since（）给出0

1 个答案: