Heap Walker Reference View - Tree of Outgoing References

     

The tree of outgoing references is one of the view modes in the reference view of the heap walker. For following long chains of references, the tree of outgoing references can be preferable to the reference graph.
  There is always one instance visible at a time whose class name or array type is given above the field table. Above the upper right corner of the table, navigation controls allow to move back and forth through all the instances or arrays in the current object set.

The instance navigation is linked among the following views of the heap walker:

This allows you to easily switch back and forth between these views while keeping the focus on the same object.

  The order of the instances in the object set can be adjusted to
  • unsorted
    The objects are in a random order. This is the default setting.
  • sorted by shallow size
    Objects with a larger shallow size are displayed first.
  • sorted by retained size
    Objects with a larger retained size are displayed first.
  • sorted by allocation time (oldest first)
    Objects with a greater age are displayed first. The "Record object allocation times" feature has to be activated on the "Memory Profiling" tab of the profiling settings dialog, otherwise this sort mode is not available and a warning message is displayed. This sorting only works for recorded objects. Unrecorded objects are appended to the end of the sorted set.
  • sorted by allocation time (newest first)
    Like the above sort mode, only that objects with a smaller age are displayed first.

Please see the key concepts of the heap walker for an explanation of the different size types.

Sorting can take a few seconds, depending on the size of the heap. A progress dialog is shown while the objects are sorted.

After changing the sort order, the displayed index is set to one.

  Above the main view, the the following additional information is displayed:

Please see the key concepts of the heap walker for an explanation of the different size types.

  Each reference node consists of three parts:
  • Field name
    The field name of the object in the parent node that holds the referenced object
  • Reference icon
    The reference icon separates the holder from the referenced object. The icon is one of
    • A regular reference.
    • A reference from an object that is already present as an ancestor node. This indicates a reference cycle. Cycles are more conveniently analyzed in the reference graph
  • Referenced object
    This is the object referenced by the outgoing reference. Direct child references below this node refer to this object.
  Each object is optionally annotate with an object ID. With this ID, you can check whether two objects are the same or not. The display of IDs can be switched of the the context menu, the View menu and the view settings of the heap walker.
  To add a selection step from this view you can select one or multiple objects and click the [Use ...] button above the graph and choose in the popup menu. There is a corresponding entry in the context menu. Multiple objects are selected by keeping the SHIFT key pressed during selection. The following selection modes are available:
  • Selected Objects
    A new object set will be created that contains only the selected instances.
  • Exclusively Referenced Objects
    A new object set will be created that contains all objects that would be garbage collected if the selected objects did not exist.
  • Items in Selected Collection
    This option is only enabled if you select an array of objects or a standard collection from the java.util package. A new object set will be created that contains the objects in the array or collection. If you select a map collection, you are prompted whether you want to include the key objects as well.

After your selection, the view helper dialog will assist you in choosing the appropriate view for the new object set.