Allocation Call Tree

   

  The allocation call tree shows a top-down call tree cumulated for all threads and filtered according to the active filter sets which is similar to the one shown in the call tree view in JProfiler's CPU section except that it shows allocations of class instances and arrays instead of time measurements.

In order to prepare an allocation call tree, you have to click on the  calculate toolbar button or choose View->Calculate allocation call tree from JProfiler's main menu. If an allocation tree has already been calculated, the context sensitive menu also gives access to this action.

Before the allocation call tree is calculated, the allocation options dialog is shown. The class or package selection as well as the selected liveness mode are displayed at the top of the allocation call tree view.

  JProfiler automatically detects J2EE components and displays the relevant nodes in the allocation call tree with special icons that depend on the J2EE component type:

 servlets
 JSPs
 EJBs

For JSPs and EJBs, JProfiler shows a display name:
  • JSPs
    the path of the JSP source file
  • EJBs
    the name of the EJB interface

If URL splitting is enabled, each request URL creates a new node with a  special icon and the prefix URL:, followed by the part of the request URL on which the allocation call tree was split. Note that URL nodes group request by the displayed URL.

You can disable both J2EE component detection as well as URL splitting on the Java Subsystems tab of the profiling settings. Also, the URL splitting method can be customized in the profiling settings or with a custom handler in the profiling API.

  The allocation call tree view has an aggregation level selector. It allows you to switch between
  • methods
    Every node in the tree is a method call. This is the default aggregation level. Special J2EE component methods have their own icon (see above) and display name, the real class name is appended in square brackets.
  • classes
    Every node in the tree is a single class. J2EE component classes have their own icon (see above) and display name, the real class name is appended in square brackets.
  • packages
    Every node in the tree is a single package. Sub-packages are not included.
  • J2EE components
    Every node in the tree is a J2EE component. If the component has a separate display name, the real class names are omitted.

When you switch between two aggregation levels, JProfiler will make the best effort to preserve your current selection. When switching to a a more detailed aggregation level, there may not be a unique mapping and the first hit in the allocation call tree is chosen.

The allocation call tree doesn't display all method calls in the JVM, it only displays

  • unfiltered classes
    Classes which are unfiltered according to your configured filter sets are used for the construction of the allocation call tree.
  • first level calls into unfiltered classes
    Every call into a filtered class that originates from an unfiltered class is used for the construction of the allocation call tree. Further calls into filtered classes are not resolved. This means that a filtered node can include information from other filtered calls. Filtered nodes are painted with a red marker in the top left corner.
  • thread entry methods
    The methods Runnable.run() and the main method are always displayed, regardless of the filter settings.

A particular node is a bridge node if it would normally not be displayed in the view, but has descendant nodes that have to be displayed. The icons of bridge nodes are grayed out. For the allocation call tree view this is the case if the current node has no allocations, but there are descendant nodes that have allocations.

  When navigating through the allocation call tree by opening method calls, JProfiler automatically expands methods which are only called by one other method themselves. To quickly expand larger portions of the allocation call tree, select a method and choose View->Expand 10 levels from the main window's menu or choose the corresponding menu item from the context menu. If you want to collapse an opened part of the allocation call tree, select the topmost method that should remain visible and choose View->Collapse all from the main window's menu or the context menu.
  If a method node is selected, the context menu allows you to quickly add a method trigger for the selected method with the  add method trigger action. A dialog will be displayed where you can choose whether to add the method interception to an existing method trigger or whether to create a new method trigger.
  Nodes in the allocation call tree can be hidden by selecting them and hitting the DEL key or by choosing Hide Selected from the context menu. Percentages will be corrected accordingly as if the hidden node did not exist. All similar nodes in other call stacks will be hidden as well.

When you hide a node, the toolbar and the context menu will get a Show Hidden action. Invoking this action will bring up a dialog where you can select hidden elements to be shown again.

  If enabled in the view settings, every node in the allocation call tree has a percentage bar whose length is proportional to the total number of allocations including all descendant nodes and whose light-red part indicates the percentage of allocations in the current node.
  Every node in the allocation call tree has textual information attached that depends on the allocation call tree settings and shows
  • a percentage number which is calculated with respect to the root of the tree or calling node.
  • a size measurement in bytes or kB which displays the shallow size of those objects which were allocated here (depends on cumulation view setting, see below).
  • an allocation count which shows how many instances of classes and arrays have been allocated here (depends on cumulation view setting, see below).
  • a name which depends on the aggregation level:
    • methods
      a method name that is either fully qualified or relative with respect to to the calling method.
    • classes
      a class name.
    • packages
      a package name.
    • J2EE components
      the display name of the J2EE component.
  • a line number which is only displayed if
    • the aggregation level is set to "methods"
    • line number resolution has been enabled in the profiling settings
    • the calling class is unfiltered

    Note that the line number shows the line number of the invocation and not of the method itself.

The size and the allocation count are either cumulated for all calls below the associated node or not, depending on the corresponding cumulation view setting. Note that allocations performed in calls to filtered classes are consolidated in the first call into a filtered class.

  If garbage collected objects are shown, you can reset the accumulated data by clicking on the reset action in the toolbar or choosing the the Reset garbage collector for this view menu item in the View or context menu. All garbage collector data will be cleared and the view will be empty for the "Garbage collected objects" mode until further objects are garbage collected and a new allocation call tree or allocation hot spots are calculated. Note that you can force garbage collection by clicking on the garbage collector  tool bar button or by selecting Profiler->Run garbage collector from JProfiler's main menu.
  Only recorded objects will be displayed in the allocation call tree view. See the memory section overview for further details on allocation recording.
  The View->Take heap snapshot for selection menu item and the corresponding toolbar entry take a new snapshot, switch to the heap walker view and create an object set with the currently selected class and allocation spot.