ABSTRACT
The basic principles of concurrent collection were initially devised as a means to reduce pause times for garbage collection on uniprocessors. Early papers used terms such as ‘concurrent’, ‘parallel’, ‘on-the-fly’ and ‘real-time’ interchangeably or inconsistently. In Chapter 14 we defined the modern usage of ‘parallel’. Here, we define the remaining terms. So far, we have assumed that the mutator is suspended while garbage collection proceeds, and that each collection cycle terminates before the mutator can continue. As before, Figure 14.1a illustrates different collection styles by one or more horizontal bars, with time proceeding from left to right, and shows mutator execution in white while each collection cycle is represented as a distinct non-white shade. Thus, grey boxes represent actions of one garbage collection cycle, and black boxes those of the next.
