Sync with Lock

syncLock.go

package main

import (
	"log"
	"sync"
)

type MyStruct struct {
	field int
}

var lockCached = struct {
	sync.RWMutex
	val *MyStruct
}{}

func initMyStruct() MyStruct {
	return MyStruct{field: 1}
}

func getIntLock(ident int) *MyStruct {
	lockCached.Lock()

	log.Println("lock", ident)
	if lockCached.val == nil {
		log.Println("Initializing GetInt")
		x := initMyStruct()
		lockCached.val = &x
	}

	lockCached.Unlock()
	log.Println("lock freed", ident)

	return lockCached.val
}

func main() {
	var wg sync.WaitGroup
	for x := range []int{0, 1, 2, 3, 4, 5} {
		wg.Add(1)
		go func(ident int) {
			defer wg.Done()
			log.Println(getIntLock(ident))
		}(x)
	}

	wg.Wait()
}