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.
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.
Please see the key concepts of the heap walker for an explanation of the different size types.
For classes there is a special condition that prevents garbage collection: Since each instance has an implicit reference to its class, any live instance prevents a class from being garbage collected. This construct groups all such instances for reasons of conciseness. In this way you can also select all instances of a specific class (rather than a specific class name).
A set of live instances that reference a yellow class object (see above) has a green background.
Classes (objects of java.lang.Class) have a yellow background.
In most circumstances, classes are the last step on the path to the GC root that you are interested in. Classes are not garbage collector roots, but in all situations where no custom classloaders are used it is appropriate and easier to treat them as such. This is JProfiler's default mode when searching for garbage collector roots, you can change this in the path to root options dialog.Class objects have references to
Note that class objects have no reference to their super class.
Classes are garbage collected together with their classloader when
By default, the reference graph only shows the direct incoming and outgoing references of the current instance. You can expand the graph by double clicking on any object. This will expand either the direct incoming or the outgoing references for that object, depending on the direction you're moving in. Selective actions for expanding the graph are available in the view-specific toolbar and the context menu:
If applicable, an instance has
plus and minus signs at the left and the right side to show or hide
incoming and outgoing references. The controls at the left side are
for incoming, the controls at the right side for outgoing references. The plus signs have the same effect
as the Show outgoing references
and the
Show incoming references
actions. A minus sign hides all outgoing references and all objects that are not connected to
the central instance. This can have the effect that the object on which you click the minus sign is hidden
as well.
Additionally, the plus and minus signs give you the following indications:
To reset the graph to its original state, you can choose Reset graph from the context menu.
The reference graph offers a number of navigation and zoom options.
A dialog will ask you whether to search for a single garbage collector root or for all roots. After that, the paths to root are searched. A progress dialog is shown while the paths to root are calculated.
After your selection, the view helper dialog will assist you in choosing the appropriate view for the new object set.