Gosk中Flask的@before_first_request相当于什么？

Question

We are switching a flask app to golang for performance reasons. In flask, there is "before_first_request" which indicates a function to be run when the app gets started. This function gets run once and only once. I've been reading through the docs but can't find any equivalent in golang....does it exist? (I imagine it doesn't have to be part of the net/http package)

Our flask:

@before_first_request
def before(*args, **kwargs):
    ....
    return

Answer 1

one way to do it is to put your function logic inside the func init() { ... } method of your module.

Otherwise you could use sync.Once

http://play.golang.org/p/SEJxEEDnxt

package main

import (
    "fmt"
    "sync"
)

func main() {
    var once sync.Once
    onceBody := func() {
        fmt.Println("Only once")
    }
    done := make(chan bool)
    for i := 0; i < 10; i++ {
        go func() {
            once.Do(onceBody)
            done <- true
        }()
    }
    for i := 0; i < 10; i++ {
        <-done
    }
}