Invisible Concurrency

We've seen in the previous exercise, the effects of concurrency through race conditions, but we want to see them in practice. It is easy to understand that concurrency problems are difficult to visualize as they do not manifest in the same way every time we run a program. That's why we are focusing on finding ways to synchronize concurrent work. One easy way to visualize it, however, but that is difficult to use in tests, is to print out each concurrent routine and see the order in which these routines are called. In the previous exercise, for example, we could have sent another parameter with a name and printed the name of the function at each iteration in the for loop.

If we want to see the effects of concurrency and still be able to test it, we could use the atomic package again, this time with strings so that we can build a string containing a message from each Goroutine. For this scenario, we will use the sync package again, but we will not make...