// access to shared memory among threads
// controlled using locks. Problem is that the programmer
// is then responsible to locking and unlocking.
//
// The basic idea here is to start a bunch of thread and
// have them all increment a single variable
//
// Author:  gtowell
// Created: August 2022

package main

import (
	"fmt"
	"sync"
)
var (
	mu sync.Mutex
	counter int64
)
func main()  {
	var wg sync.WaitGroup
	threads:= 100
	times := 1000000
	for rz:=0; rz<threads; rz++ {
		wg.Add(1)
		go func(_rr int) {
			defer wg.Done()
			for th:=0; th<times; th++ {
				mu.Lock()
				counter++
				mu.Unlock()
			}
		}(rz)
	}
	wg.Wait()
	fmt.Printf("Counter done   %v\n", counter);	
	fmt.Printf("Counter expect %v\n", (threads*times))
}