What is the main limitation of the Reference Counting garbage collection algorithm?
Reference counting suffers from cyclic references (which never reach count 0), assignment update overhead, and storage space requirements.
The Mark-and-Sweep Garbage Collection algorithm operates in two phases. What occurs during the 'Mark' phase?
The Mark phase follows pointers starting from root references to flag every reachable object in the heap graph.
In a loop in a control flow graph, a node $d$ is said to 'dominate' node $n$ (written $d \text{ dom } n$) if:
Dominance definition: $d \text{ dom } n$ holds if node $d$ appears on all paths from entry to node $n$.
In Control Flow Graphs, what is a 'Back Edge'?
A back edge in a CFG goes from a node $a$ to an ancestor $b$ in the dominance tree ($b \text{ dom } a$), establishing natural loop cycles.
What is a 'Natural Loop' in a Control Flow Graph?
Natural loops have a unique header dominating all loop nodes and at least one back edge leading back to the header.