singleton

singleton.go

package main

import "fmt"

type SingletonCon struct {
    url string
    port string
}

var singletonConInstance *SingletonCon

func GetInstance() *SingletonCon {
    if singletonConInstance == nil {
        fmt.Println("Create singleton instance")
        
        singletonConInstance = &SingletonCon{
            url: "url",
            port: "port",
        }
    } else {
        fmt.Println("Singleton instance already created.")
    }
    return singletonConInstance
}

func main() {
    for i := 0; i < 10; i++ {
        GetInstance() 
        // This will executed 10 times
        // use sync.Once | sync.OnceFunc | sync.Value
        // only execute one time
    }
}