双buffer防止 map读写并发

package main

import (
	"fmt"
	"strconv"
	"sync"
)

var (
	s       [2]map[string]string
	current = 0
	wg      sync.WaitGroup
)

func w(s1 string) {
	tmpIndex := (current + 1) % 2
	if s[tmpIndex] == nil {
		s[tmpIndex] = make(map[string]string)
	}
	s[tmpIndex][s1] = s1
	current = tmpIndex
	fmt.Println(current)
}
func r() {
	for i := 0; i < 100; i++ {
		//fmt.Println(current, s[current])
	}
}

func main() {
	w("1")
	r()

	wg.Add(2)
	go func() {
		defer wg.Done()
		for i := 0; i < 100; i++ {
			//time.Sleep(5)
			r()
		}
	}()

	go func() {
		defer wg.Done()
		for i := 0; i < 5; i++ {
			//time.Sleep(5)
			w(strconv.Itoa(i))
		}
	}()
	wg.Wait()

}