Using the Memory Statistics view

The Memory Statistics views displays statistics about the application heap. It provides detailed information such as the number of classes loaded, the number of instances that are alive, and the memory size allocated by every class. Memory statistics are available at the package, class, and instance level.

Prerequisites:

The Memory Statistics view provides a number of controls to allow you to manipulate the information shown within the view:

Working with display modes

There are three display modes are available based on the three object types: packages, classes, and instances.

  1. To switch between the package, class, and instance modes, select one of the following toolbar controls:
  2. The data values displayed can also be shown as percentages. To display the data as percentages, select Show as Percentage % in the toolbar.

The data displayed depends what object type is selected. The following table summarizes the data available in each display mode.

Column heading Package statistics 
Icon for package
Class statistics
Icon for package
Instance statistics
Icon for package
Total Instances: The total number of instances that had been created of the selected package, class, or method. Accumulated by package Accumulated by class Count
Live Instances: The number of instances of the selected package, class, or method, where no garbage collection has taken place. Accumulated by package Accumulated by class Count
Collected: The number of instances of the selected package, class, or method, that were removed during garbage collection. Accumulated by package Accumulated by class Count
Total Size: The total size (in bytes) of the selected package, class, or method, of all instances that were created for it, including whatever has been removed through garbage collection. Accumulated by package Accumulated by class Size
Active Size: The summed size of all live instances.  Accumulated by package Accumulated by class Size

Note: The totals shown in this view represent only the data that has been collected since you started monitoring your process. If you start monitoring your process half way through the execution, you will only see the totals from the point that you started monitoring. As well, in the package mode, only the totals of the collected classes for that package are shown. Classes that you have filtered out will not be included in the totals.

Working with columns

There are different controls available that allow you to manipulate the columns displayed in this view.

  1. To specify which columns to display in the view, select the Choose Column Choose column icon button in the toolbar.
  2. In the Choose Columns dialog, select the columns that you want displayed in the view. Click OK to apply the changes.
  3. To show the change in each numeric column since the last refresh, select Show Delta Columns Show Delta icon in the toolbar.
  4. To sort column data, click the title of a column. Click the title of the column again to sort it in reverse order. The title of the column is prefixed with < if the column is sorted in ascending order or with > if it is sorted in descending order.

Filtering profiling data

Profiling filters can be applied to the Memory Statistics view to reduce the amount of data shown in the view. Profiling filters can be used across different profiling views as long as the view supports the filter. See the topic on Applying profiling filters for more details.

Opening other views

Other profiling views and source code views can be opened from the Memory Statistics view.

  1. To open the object references of a selected object, right-click and select Show Object References Show object references. The Object References view will be opened and populated with data for the selected object.
  2. To open the source code view of a selected object, right-click and select Open Source Open source icon.

Exporting the data in the view

The data within the Memory Statistics view can be exported to an HTML document.

  1. To export the data in the view, select Export to HTML Export HTML icon in the toolbar.
  2. In the Export to HTML dialog, specify the file name that the data will be saved to.
  3. Click OK to save the data.

Refreshing the view

The Memory Statistics view can be refreshed using the Refresh Refresh Views icon button in the toolbar. When the view is refreshed, changes are marked with delta icons:

 


Related concepts
Overview of the Profiling Tool
Profiling resources

Related tasks
Profiling an application
Identifying memory-intensive classes


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