If you’re already familiar with languages that handle concurrency through memory access synchronization, then you’ll probably immediately recognize Mutex. If you don’t count yourself among that group, don’t worry, Mutex is very easy to understand. Mutex stands for “mutual exclusion” and is a way to guard critical sections of your program. If yo…

mutex.go

package main

import (
	"fmt"
	"sync"
)

func main() {
	var count int
	var lock sync.Mutex
	increment := func() {
		lock.Lock()
		defer lock.Unlock()
		count++
		fmt.Printf("Incrementing: %d\n", count)
	}
	decrement := func() {
		lock.Lock()
		defer lock.Unlock()
		count--
		fmt.Printf("Decrementing: %d\n", count)
	}
	// Increment
	var arithmetic sync.WaitGroup
	for i := 0; i <= 5; i++ {
		arithmetic.Add(1)
		go func() {
			defer arithmetic.Done()
			increment()
		}()
	}
	// Decrement
	for i := 0; i <= 5; i++ {
		arithmetic.Add(1)
		go func() {
			defer arithmetic.Done()
			decrement()
		}()
	}
	arithmetic.Wait()
	fmt.Println("Arithmetic complete.")
}