package main

import (
	"fmt"
	"sync"
	"sync/atomic"
)

var nextWorkerID uint32

func getNextWorkerID() uint {
	atomic.AddUint32(&nextWorkerID, 1)
	return uint(nextWorkerID)
}

const total = 500

func main() {
	var wg sync.WaitGroup
	var m sync.Map
	for i := 0; i < total; i++ {
		wg.Add(1)
		go func() {
			defer wg.Done()
			id := getNextWorkerID()
			if _, loaded := m.LoadOrStore(id, 0); loaded {
				fmt.Printf("conflict: %d\n", id)
			}
		}()
	}
	wg.Wait()
	var cnt int
	m.Range(func(_, _ interface{}) bool { cnt++; return true })
	if cnt != total {
		fmt.Printf("map size: %d != %d\n", cnt, total)
	}
}