Sample mutex 2

02-mutex.go

package main

import (
	"fmt"
	"sync"
)

func main() {
	m := &sync.Mutex{}
	wg := &sync.WaitGroup{}
	wg.Add(100)
	s := make([]int, 0)
	for i := 0; i < 100; i++ {
		go update(&s, m, wg)
	}
	wg.Wait()
	fmt.Println(len(s))
}

func update(s *[]int, m *sync.Mutex, wg *sync.WaitGroup) {
	m.Lock()
	*s = append(*s, 1)
	m.Unlock()
	wg.Done()
}