Skip to main content


Eclipse Community Forums
Forum Search:

Search      Help    Register    Login    Home
Home » Eclipse Projects » Memory Analyzer » MAT Heap Dump Comparison Algorithm(Description of the )
MAT Heap Dump Comparison Algorithm [message #1816928] Tue, 12 November 2019 09:50 Go to next message
Porfirio Tramontana is currently offline Porfirio TramontanaFriend
Messages: 1
Registered: November 2019
Junior Member
I am writing a paper about a tool using the comparisons between two heap dumps provided by MAT to characterize potential memory leaks.
I would ask if there are some available documents describing the algorithm implemented by MAT for detecting duplicated objects by the comparison of two different hprof files.

I have found some infos updated at 2010 in the memoryanalyzer blogspot web site but I am still curious to know what algorithm is implemented in the current version of MAT.
Re: MAT Heap Dump Comparison Algorithm [message #1817198 is a reply to message #1816928] Mon, 18 November 2019 13:32 Go to previous messageGo to next message
Andrew Johnson is currently offline Andrew JohnsonFriend
Messages: 205
Registered: July 2009
Senior Member
The comparison facilities are as follows:


  1. Compare to another Heap Dump
    This compares two 'histogram' tables which list all the class names, number of instances of that class and the total shallow heap. The comparison just matches on class names and then shows the delta of the numeric values in each row between each table.
  2. org.eclipse.mat.api:compare batch utility
    This does the same as the first, but generates HTML and CSV reports.
  3. Comparison basket
    This allows the comparison of any two tables or trees. The records are matched by the value of the first column. See https://help.eclipse.org/2019-09/topic/org.eclipse.mat.ui.help/tasks/comparingdata.html. The values of subsequent columns can then be displayed as absolute values, difference from the first table, difference from the preceding table or as percentages. If the comparisons are from the same snapshot then set operations allow selection of objects in one row in one table but not in the corresponding row in the other table (or other set-wise operations).

Re: MAT Heap Dump Comparison Algorithm [message #1823428 is a reply to message #1816928] Thu, 26 March 2020 12:57 Go to previous message
Andrew Johnson is currently offline Andrew JohnsonFriend
Messages: 205
Registered: July 2009
Senior Member
I have improved the comparison feature for MAT. This is still under development but is available as a nightly snapshot build. If you are still interested I could explain more about how duplicated objects from different heap dumps are matched. There is scope for improvement, so any ideas would be welcome.
Previous Topic:Retained heap calculated incorrectly in dominator tree?
Next Topic:Memoryanalyzer.exe won't boot after editing .ini file
Goto Forum:
  


Current Time: Thu Mar 28 16:37:40 GMT 2024

Powered by FUDForum. Page generated in 0.03355 seconds
.:: Contact :: Home ::.

Powered by: FUDforum 3.0.2.
Copyright ©2001-2010 FUDforum Bulletin Board Software

Back to the top