7. Competition

Javascript is mono-task non-preemptive. These words mean that the evaluator does only one thing at a time, and only that thing until it is completed. Two major consequences:

• each run can be considered to be in the critical section, since nothing can prevent it from being completed;

• an infinite loop will never end.

On the other hand, Javascript's primitive execution library (e.g. the one provided by browsers) can perform parallel actions such as fetching pages, images and scripts, and processing them appropriately once their content has been obtained. Communication between these two worlds takes place via events and callbacks. The term callback can also be translated as "return function", but this is less light-hearted than "suite", which will be adopted here. English-language...