Mutexes

If you are working with concurrent applications, you have to deal with more than one resource potentially accessing some memory location. This is usually called race condition.

In simpler terms, a race condition is similar to that moment where two people try to get the last piece of pizza at exactly the same time--their hands collide. Replace the pizza with a variable and their hands with Goroutines and we'll have a perfect analogy.

There is one character at the dinner table to solve this issues--a father or mother. They have kept the pizza on a different table and we have to ask for permission to stand up before getting our slice of pizza. It doesn't matter if all the kids ask at the same time--they will only allow one kid to stand.

Well, a mutex is like our parents. They'll control who can access the pizza--I mean, a variable--and they won't allow anyone else to access it.

To use a mutex, we have to actively lock it; if it's already locked (another Goroutine is using it), we'll have...