210. Introducing structured concurrency

If you are as old as I am, then most probably you started programming with a language such as BASIC or a similar unstructured programming language. At that time, an application was just a sequence of lines that defined a sequential logic/behavior via a bunch of GOTO statements, driving the flow by jumping like a kangaroo back and forward between the code lines. Well, in Java, the building blocks of a typical concurrent code are so primitive that the code looks somewhat like unstructured programming because it is hard to follow and understand. Moreover, a thread dump of a concurrent task doesn’t provide the needed answers.

Let’s follow a snippet of Java concurrent code and stop every time we have a question (always check the code below the question). The task is to concurrently load three testers by ID and team them up in a testing team. First, let’s list the server code (we will use this simple code to serve us in this...