先不运行go main函数

Question

package main
import (
    "bytes"
    "encoding/json"
    "io/ioutil"
    "log"
    "net/http"
    "os"
    "os/signal"
    "strings"
    "unicode/utf8"
    "sync"
    "github.com/robfig/cron"
     cpu "github.com/shirou/gopsutil/cpu"
    "fmt"
)

const NumofResource = 4

// 구조체
type HostInfo struct {
    Hostid string
}

var c *cron.Cron
var lastCPUTimes []cpu.TimesStat

func main() {
    fmt.Println("1.main.go > main() start")
    defer l4g.Close()

var err interface{}
lastCPUTimes, err = cpu.Times(false) //nil
fmt.Println("2.main.go > err", err)
fmt.Println("3.main.go > lastCPUTimes", lastCPUTimes)

if err != nil {
    l4g.Error(err)
}
}

我知道main函数先执行。但是，我们确认首先执行了名为 cpu_windows.go 的库。为什么？

cpu_windows.go : Times(bool) false

cpu_windows.go : common.ProcGetSystemTimes.Call 1

cpu_windows.go : Times(bool) true

cpu_windows.go : return perCPUTimes()

1.main.go : main() start

cpu_windows.go : Times(bool) false

cpu_windows.go : common.ProcGetSystemTimes.Call 1

2.main.go : err

Answer 1

specification says :

If a package has imports, the imported packages are initialized before initializing the package itself.

和

Program execution begins by initializing the main package and then invoking the function main.

接下来是 initialization code在导入的 cpu 包中，在 main 中的任何代码之前执行。