Memory Analyzer provides a dominator tree of the object graph. The transformation of the object reference graph into a dominator tree allows you to easily identify the biggest chunks of retained memory and the keep-alive dependencies among objects. Below is an informal definition of the terms.
An object x dominates an object y if every path in the object graph from the start (or the root) node to y must go through x.
The immediate dominator x of some object y is the dominator closest to the object y.
A dominator tree is built out of the object graph. In the dominator tree each object is the immediate dominator of its children, so dependencies between the objects are easily identified.
The dominator tree has the following important properties:
- The objects belonging to the sub-tree of x (i.e. the objects dominated by x ) represent the retained set of x .
- If x is the immediate dominator of y , then the immediate dominator of x also dominates y , and so on.
- The edges in the dominator tree do not directly correspond to object references from the object graph.
